Hydrolytic degradation of branched PLA produced by reactive extrusion
Publication date: Available online 9 November 2018Source: Polymer Degradation and StabilityAuthor(s): Heather Simmons, Marianna KontopoulouAbstractReactive extrusion using dicumyl peroxide (DCP) and a tri-functional coagent, triallyl trimesate (TAM) is implemented to introduce long-chain branching (LCB) in poly(lactic acid) (PLA). The effects of this modification on the long-term hydrolysis of PLA are assessed by monitoring the mass, molar mass distributions, and thermal properties of specimens exposed to hydrolytic degradation at a temperature of 60 °C. A slow initial rate of mass loss coupled with an immediate and ...
Source: Polymer Degradation and Stability - November 10, 2018 Category: Chemistry Source Type: research

Synergistic effect of (3-Aminopropyl)Trimethoxysilane treated ZnO and corundum nanoparticles under UV-irradiation on UV-cutoff and IR-absorption spectra of acrylic polyurethane based nanocomposite coating
Publication date: Available online 9 November 2018Source: Polymer Degradation and StabilityAuthor(s): Mhd Abd Cader Mhd Haniffa, Yern Chee Ching, Cheng Hock Chuah, Kuan Yong Ching, Liou Nai-ShangAbstractZnO and corundum (α–Al2O3) nanoparticles were successfully synthesized by aqueous precipitation and sintering techniques respectively. ZnO nanoparticles were effectively coated with (3-aminopropyl)trimethoxysilane (APTMS) by polycondensation method to prevent the photocatalytic activity of ZnO during a UV-weathering study. X-ray diffractogram and FTIR were used to confirm the crystalline structure of as prepared...
Source: Polymer Degradation and Stability - November 10, 2018 Category: Chemistry Source Type: research

Effects of chemical composition on the in vitro degradation of micelles prepared from poly(D,L-lactide-co-glycolide)-poly(ethylene glycol) block copolymers
Publication date: Available online 9 November 2018Source: Polymer Degradation and StabilityAuthor(s): Feng Su, Chenglong Li, Rongye Li, Peng Yun, Yuandou Wang, Laishun Xi, Yangsheng Chen, Suming LiAbstractIn this work, a series of poly(D,L-lactide-co-glycolide)-poly(ethylene glycol) (PLGA-PEG) diblock copolymers with relatively short PLGA blocks were synthesized by ring-opening polymerization of D,L-lactide and glycolide in the presence of monomethoxy PEG with Mn of 2000. Spherical micelles were obtained by self-assembly of copolymers using direct dissolution method. The degradation of the micelles was investigated under i...
Source: Polymer Degradation and Stability - November 10, 2018 Category: Chemistry Source Type: research

Editorial Board
Publication date: November 2018Source: Polymer Degradation and Stability, Volume 157Author(s): (Source: Polymer Degradation and Stability)
Source: Polymer Degradation and Stability - November 8, 2018 Category: Chemistry Source Type: research

A comparative study on in vitro degradation behavior of PLLA-based copolymer monofilaments
Publication date: Available online 7 November 2018Source: Polymer Degradation and StabilityAuthor(s): Daokun Shi, Yahong Kang, Guoyi Zhang, Chenguang Gao, Wei Lu, Caihong Yang, Hua Zou, Hongyan JiangAbstractThree kinds of high molecular weight polymers were synthesized by ring-opening polymerization with various monomer feeding ratios (named as PLLA, PLCL 95/5 and PLGC 80/15/5, respectively). Then oriented monofilament was produced through melt-extrusion and tensile orientation based on each kind of polymer. In vitro degradation properties of the monofilaments were studied over a range of degradation time from 1 to 21 days...
Source: Polymer Degradation and Stability - November 8, 2018 Category: Chemistry Source Type: research

Corrigendum to “Radiation stability of silicon-organic varnish modified with nanoparticles” [Polym. Degrad. Stabil. 153 185–191]
Publication date: Available online 7 November 2018Source: Polymer Degradation and StabilityAuthor(s): M.M. Mikhailov, V.V. Neshchimenko, A.V. Grigorevskiy, A.N. Sokolovskiy, A.S. Bakhtaulova, I.S. Vaschenkov (Source: Polymer Degradation and Stability)
Source: Polymer Degradation and Stability - November 8, 2018 Category: Chemistry Source Type: research

Effects of heat treatment on the chemical compositions and thermal decomposition kinetics of Japanese cedar and beech wood
This study investigated variations in the chemical compositions and thermal decomposition kinetics of Japanese cedar and beech wood during heat treatment. Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectra revealed that various reactions, such as hemicellulose deacetylation, condensation reactions causing lignin cross-linking, and reductions in cellulose amorphous regions, were carried out during the heat treatment process. In addition, combinations of FTIR spectra and principal component analysis (PCA) succeeded in discriminating the major changes in functional groups of wood at various heat tr...
Source: Polymer Degradation and Stability - November 8, 2018 Category: Chemistry Source Type: research

Application of an in vitro plant ecotoxicity test to unused biodegradable mulches
Publication date: December 2018Source: Polymer Degradation and Stability, Volume 158Author(s): H. Serrano-Ruíz, L. Martín-Closas, A.M. PelachoAbstractBiodegradable plastics have emerged as an encouraging alternative to reduce the production of plastic waste, especially for agricultural mulches. However, degradation of these plastics in the field may involve the release of products from the mulch into the soil, before and during the in-soil biodegradation. The present work aims to assess the potential effects on two agricultural plant species (Lactuca sativa L. –lettuce-, and Lycopersicon esculentum Mill...
Source: Polymer Degradation and Stability - November 8, 2018 Category: Chemistry Source Type: research

Consolidation of degraded polyurethane foams by means of polysiloxane mixtures: Polycondensation study and application treatment
Publication date: December 2018Source: Polymer Degradation and Stability, Volume 158Author(s): Céline Daher, Isabelle Fabre-Francke, Nathalie Balcar, Gilles Barabant, Sophie Cantin, Odile Fichet, Hervé Chéradame, Bertrand Lavédrine, Agnès Lattuati DerieuxAbstractPolyurethane (PUR) ester foams are found in 20th century museum collections in a variety of artworks and objects. Unfortunately PUR ester foams are prone to degradation, and present – among other plastic materials – important conservation issues. They are very sensitive to moisture, and their hydrolysis leads to severa...
Source: Polymer Degradation and Stability - November 7, 2018 Category: Chemistry Source Type: research

A preliminary study on the physicochemical properties of pigmented Sty/nBA/MMA emulsion films: The effect of thermal ageing
Publication date: Available online 3 November 2018Source: Polymer Degradation and StabilityAuthor(s): T. Fardi, E. Kampasakali, Z. Terzopoulou, V. Pintus, E. Pavlidou, M. Schreiner, D. Bikiaris, G. KyriacouAbstractThe effect of temperature and humidity on the physicochemical and mechanical properties of pigmented Sty/nBA/MMA emulsion polymers containing synthetic organic pigments was studied. Thin films of artist's commercial paints from Liquitex (U.S.A.) and Rembrandt (NL) containing Azo yellow (PY3), diketopyrrolopyrrole red (PR264), phthalocyanine blue (PB15) and phthalocyanine green (PG7) were naturally dried and subje...
Source: Polymer Degradation and Stability - November 4, 2018 Category: Chemistry Source Type: research

Consolidation of degraded polyurethane foams by mean of polysiloxane mixtures: Polycondensation study and application treatment
Publication date: Available online 2 November 2018Source: Polymer Degradation and StabilityAuthor(s): Céline Daher, Isabelle Fabre-Francke, Nathalie Balcar, Gilles Barabant, Sophie Cantin, Odile Fichet, Hervé Chéradame, Bertrand Lavédrine, Agnès Lattuati DerieuxAbstractPolyurethane (PUR) ester foams are found in 20th century museum collections in a variety of artworks and objects. Unfortunately PUR ester foams are prone to degradation, and present – among other plastic materials – important conservation issues. They are very sensitive to moisture, and their hydrolysis leads to...
Source: Polymer Degradation and Stability - November 3, 2018 Category: Chemistry Source Type: research

A novel star-shaped, cardanol-based bio-prepolymer: Synthesis, UV curing characteristics and properties of cured films
Publication date: Available online 2 November 2018Source: Polymer Degradation and StabilityAuthor(s): Jun-Jie Li, Jian Sun, Yong-Xin Xie, Chen Zhao, Hong-Xia Ma, Cheng-Mei LiuAbstractStarting from renewable Cardanol, a novel inherently fire-retardant UV curable bio-based prepolymer (AEHCPP) with phosphazene core and six Cardanol arms are prepared in this report. The chemical structure of all newly prepared intermediates compounds and AEHCPP are well-characterized using nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR). UV-curable mixture consisting of AEHCPP and different diluents were for...
Source: Polymer Degradation and Stability - November 3, 2018 Category: Chemistry Source Type: research

A predictive model for polyethylene cable insulation degradation in combined thermal and radiation environments
Publication date: Available online 3 November 2018Source: Polymer Degradation and StabilityAuthor(s): Anna Vykydalová, Tibor Dubaj, Zuzana Cibulková, Gabriela Mizerová, Michal ZavadilAbstractReliable prediction of material service lifetime is important for ensuring safe operation in safety-critical systems such as nuclear facilities. Materials in these environments degrade due to several simultaneous effects, most important stressors are heat and radiation. In this work, samples of medium density polyethylene cable insulation were subjected to thermal (110 °C) and γ-radiation stress (500 ...
Source: Polymer Degradation and Stability - November 3, 2018 Category: Chemistry Source Type: research

Assessment of localization and degradation of ZnO nano-particles in the PLA/PCL biocompatible blend through a comprehensive rheological characterization
Publication date: Available online 1 November 2018Source: Polymer Degradation and StabilityAuthor(s): Yeganeh Ahmadzadeh, Amir Babaei, Alireza GoudarziAbstractThe aim of this work was to investigate the effect of addition of various amounts of zinc oxide (ZnO) nanoparticles on the polylactide/polycaprolactone (PLA/PCL) blend prepared by melt mixing method. The morphological, rheological and degradation of prepared nanocomposites were studied. The morphology was characterized as dispersed PCL droplets into the PLA matrix, and according to Young's equation, zinc oxide nanoparticles (ZnO-NPs) was anticipated to preferentially...
Source: Polymer Degradation and Stability - November 2, 2018 Category: Chemistry Source Type: research

Cutinases catalyze polyacrylate hydrolysis and prevent their aggregation
Publication date: Available online 31 October 2018Source: Polymer Degradation and StabilityAuthor(s): Ruoyu Hong, Lingqia Su, Jing WuAbstractDuring the recycling of waste paper, the accumulation of polyacrylates present in the waste paper causes the formation of tacky substances known as stickies. Deposition of these stickies on the machinery decreases the quality of the recycled paper and increases the usage of circulating water. Enzymes that hydrolyze these polyacrylates can minimize or eliminate the deposition of stickies. In initial experiments, the abilities of the cutinases from Humicola insolens, Fusarium solani and...
Source: Polymer Degradation and Stability - November 1, 2018 Category: Chemistry Source Type: research

Wear-induced mechanical degradation of plastics by low-energy wet-grinding
Publication date: Available online 31 October 2018Source: Polymer Degradation and StabilityAuthor(s): Kartik Ravishankar, Praneeth Srivanth Ramesh, Balaji Sadhasivam, Dhamodharan RaghavachariAbstractMechanical degradation of polymers reported so far, utilize cutting, impact or attrition for size reduction, which is very different from the low-magnitude forces experienced by the polymers during their service life. In this work, we have studied the effect of such low-magnitude forces, on the polymeric articles, using a low-energy rolling compression-type wet-grinder. The rolling compression action produces shear and compress...
Source: Polymer Degradation and Stability - October 31, 2018 Category: Chemistry Source Type: research

Extrusion of wood fibre reinforced poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) biocomposites: Statistical analysis of the effect of processing conditions on mechanical performance
In this study, we show that commercially-relevant mechanical properties of a wood-poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) composite can be achieved through extrusion processing, even at temperatures as high as 190 °C, by adjusting screw speed and feeding rate, and consequently the induced shear rate and residence time. Moreover, the mechanical properties of 40 wt% wood-PHBV were found to be superior to properties previously reported in the literature. Relative to neat PHBV, a 73% increase in modulus and 80% retention of tensile strength was achieved. A Taguchi approach to experimental design was adopted to ...
Source: Polymer Degradation and Stability - October 31, 2018 Category: Chemistry Source Type: research

Degradation of poly(5-hydroxy-trimethylene carbonate) in aqueous environments
Publication date: Available online 31 October 2018Source: Polymer Degradation and StabilityAuthor(s): Fei Chen, Ronghui Qi, Locke Davenport Huyer, Brian G. AmsdenAbstractPoly(5-hydroxy-trimethylene carbonate) (PHTMC) was synthesized through ring-opening polymerization of 5-benzyloxy trimethylene carbonate followed by debenzylation. The water solubility of the resulting homopolymer was measured as a function of its molecular weight, and its degradation in acidic (pH 2.0), and basic (pH 12.0) solutions of deionized water, as well as in phosphate buffered saline (PBS, pH 7.4) assessed. PHTMC exhibited notable hydrophilicity, ...
Source: Polymer Degradation and Stability - October 31, 2018 Category: Chemistry Source Type: research

In vivo studies of novel scaffolds with tannic acid addition
Publication date: December 2018Source: Polymer Degradation and Stability, Volume 158Author(s): Beata Kaczmarek, Alina Sionkowska, I. Otrocka-Domagała, I. PolkowskaAbstractScaffolds based on chitosan, collagen, and hyaluronic acid supplemented with nano-hydroxyapatite and tannic acid were obtained by using the freeze-drying method. Biocompatibility was studied by the in vivo implantation into proximal tibial bones of rabbits. The bones were drilled and the biomaterial was introduced by filling the pre-drilled space. The histological studies were carried out three months after the implantation.The results showed low st...
Source: Polymer Degradation and Stability - October 31, 2018 Category: Chemistry Source Type: research

Correlation between the chemical structure and enzymatic hydrolysis of Poly(butylene succinate), Poly(butylene adipate), and Poly(butylene suberate)
Publication date: Available online 29 October 2018Source: Polymer Degradation and StabilityAuthor(s): Zhenhui Bai, Ke Shi, Tingting Su, Zhanyong WangAbstractPoly(butylene succinate) (PBS), poly(butylene adipate) (PBA), and poly(butylene suberate) (PBSub) were synthesized and enzymatic hydrolysis was performed in the presence of cutinase. The residues degraded at different times were characterized with respect to their molecular, thermal, crystalline, and chemical structures. The results showed that the degradation behavior of the three polyesters highly depends on their CH2/CO ratio, morphology, and thermal characteristics...
Source: Polymer Degradation and Stability - October 30, 2018 Category: Chemistry Source Type: research

Significantly reduced pre-oxidation period of PAN fibers by continuous electron beam irradiation: Optimization by monitoring radical variation
Publication date: Available online 30 October 2018Source: Polymer Degradation and StabilityAuthor(s): Wenli Zhang, Mouhua Wang, Wenfa Zhang, Weihua Liu, Chenguang Yang, Rongfang Shen, Guozhong WuAbstractA self-shielded electron beam (EB) accelerator was connected to the front of a pre-oxidation furnace to evaluate the effect of radiation on the pre-oxidation of polyacrylonitrile (PAN) fibers; with this setup, PAN fibers could be irradiated and pre-oxidized in sequence to obtain stabilized fibers. Radiation effects during different temperature stages of the pre-oxidation process were analyzed by differential scanning calori...
Source: Polymer Degradation and Stability - October 30, 2018 Category: Chemistry Source Type: research

Biodegradable plastic designed to improve the soil quality and microbiological activity
Publication date: Available online 28 October 2018Source: Polymer Degradation and StabilityAuthor(s): Amanda Aleixo Moreira, Suzana Mali, Fabio Yamashita, Ana Paula Bilck, Maria Tereza de Paula, Aline Merci, André Luiz Martinez de OliveiraAbstractBiodegradable plastic composites were produced from mixtures of polyvinyl alcohol (PVA) and starch, which were mixed with different natural fillers [sugarcane bagasse (SB), oat hulls (OH) or silkworm exuvia (SE)] and nutrients to stimulate the biodegrading microbiota. The physicochemical and biodegradability characteristics of the produced materials were studied, in additio...
Source: Polymer Degradation and Stability - October 29, 2018 Category: Chemistry Source Type: research

Thermal stability of bacteriocin nisin in polylactide-based films
Publication date: Available online 26 October 2018Source: Polymer Degradation and StabilityAuthor(s): Pavlina Holcapkova, Anna Hurajova, Pavel Bazant, Martina Pummerova, Vladimir SedlarikAbstractThis work investigates the thermal stability of bacteriocin nisin in polylactide (PLA) and polylactide/polyethylene glycol (PLA/PEG) blends at temperatures of 90 °C–180 °C. The samples were prepared by solvent cast technique and characterized according to their mechanical and thermal properties. Research on the thermal stability of nisin in the PLA and PLA/PEG systems was carried out by exposing the given films to...
Source: Polymer Degradation and Stability - October 27, 2018 Category: Chemistry Source Type: research

Application of an in vitro plant ecotoxicity test to unused biodegradable mulches
Publication date: Available online 26 October 2018Source: Polymer Degradation and StabilityAuthor(s): H. Serrano-Ruíz, L. Martín-Closas, A.M. PelachoAbstractBiodegradable plastics have emerged as an encouraging alternative to reduce the production of plastic waste, especially for agricultural mulches. However degradation of these plastics in the field may involve the release of products from the mulch into the soil, before and during the in-soil biodegradation. The present work aims to assess the potential effects on two agricultural plant species (Lactuca sativa L.–lettuce-, and Lycopersicon esculentum...
Source: Polymer Degradation and Stability - October 27, 2018 Category: Chemistry Source Type: research

Single and hybrid electromagnetic absorbing coatings on polyacrylonitrile precursor to motivate the microwave pre-oxidation
Publication date: Available online 25 October 2018Source: Polymer Degradation and StabilityAuthor(s): Tienah H.H. Elagib, Elwathig A.M. Hassan, Cheng Fan, Keqing Han, Muhuo YuAbstractNano silicon carbide was used separately and as an auxiliary absorber for the modification of the PAN precursor fibers to upgrade their microwave absorbability in order to undergo the subsequent pre-oxidization by using microwave. Surface coatings were successfully applied to the PAN precursor and the coated fibers were pre-oxidized over the microwave furnace for 60 min. To study the effect of the coatings on the pre-oxidized fibers, a serie...
Source: Polymer Degradation and Stability - October 26, 2018 Category: Chemistry Source Type: research

Polylactide-based self-reinforced composites biodegradation: Individual and combined influence of temperature, water and compost
Publication date: Available online 25 October 2018Source: Polymer Degradation and StabilityAuthor(s): O. Gil-Castell, J.D. Badia, S. Ingles-Mascaros, R. Teruel-Juanes, A. Serra, A. Ribes-GreusAbstractSelf-reinforced polymer composites (SRCs) are proposed as a suitable alternative for composite development, based in the combination of a polymeric matrix and a polymeric fibre made of the same polymer. SRCs based in polylactide (PLA) could be fully biodegradable and presumably their valorisation routes could be assimilated to those for neat PLA. In this sense, the aim of this study was to develop new self-reinforced PLA-based...
Source: Polymer Degradation and Stability - October 26, 2018 Category: Chemistry Source Type: research

In vivo studies of novel scaffolds with tannic acid addition
Publication date: Available online 25 October 2018Source: Polymer Degradation and StabilityAuthor(s): Beata Kaczmarek, Alina Sionkowska, I. Otrocka-Domagała, I. PolkowskaAbstractScaffolds based on chitosan, collagen, and hyaluronic acid supplemented with nano-hydroxyapatite and tannic acid were obtained by using the freeze-drying method. Biocompatibility was studied by the in vivo implantation into proximal tibial bones of rabbits. The bones were drilled and the biomaterial was introduced by filling the pre-drilled space. The histological studies were carried out three months after the implantation.The results showed low ...
Source: Polymer Degradation and Stability - October 25, 2018 Category: Chemistry Source Type: research

Assessment of polyethylene degradation after aging through anaerobic digestion and composting
This study is aimed at evaluating the quality of low density polyethylene after being exposed to anaerobic digestion, composting or both processes sequentially, in order to assess for the optimum post-processing of these plastic fractions, eventually undergoing recycling processes. The alteration in the polymer's quality was first analyzed by non-destructive optical methods, including FTIR, NIR, SEM and EDX. These tests were followed by thermal and mechanical properties' assessment.The surface of the specimens showed signs of degradation, yet the extent of the changes was microscopic. The FTIR and NIR spectra showed higher...
Source: Polymer Degradation and Stability - October 22, 2018 Category: Chemistry Source Type: research

Thermal degradation of poly(alkyl methacrylate) synthesized via ATRP using 2,2,2-tribromoethanol as initiator
Publication date: Available online 18 October 2018Source: Polymer Degradation and StabilityAuthor(s): Ana Paula Rodrigues Camilo, Paula de Almeida, Cesar Liberato Petzhold, Maria Isabel FelisbertiAbstractPoly(alkyl methacrylate)s (alkyl = methyl, ethyl, n-butyl and n-hexyl) synthesized by Atom Transfer Radical Polymerization (ATRP) using 2,2,2 tribromoethanol as initiator present a first mass loss below 200 °C in thermogravimetric experiments. In order to investigate the possible mechanism of this degradation step, the polymers were subjected to thermal treatment at 150 °C under argon atmosphere. The volati...
Source: Polymer Degradation and Stability - October 19, 2018 Category: Chemistry Source Type: research

Designing reliable silicone elastomers for high-temperature applications
Publication date: Available online 12 October 2018Source: Polymer Degradation and StabilityAuthor(s): Elisa Ogliani, Liyun Yu, Piotr Mazurek, Anne L. SkovAbstractReliability and durability are strict requirements for silicone elastomers employed in high-temperature applications, if long-time device performance is desired. Improving the thermal stability of silicone elastomers is a major challenge, addressed by both the scientific and the industrial community. Nevertheless, traditional methods such as adding heat-resistant fillers or chemical modifications still suffer from considerable shortcomings. Here, it is demonstrate...
Source: Polymer Degradation and Stability - October 14, 2018 Category: Chemistry Source Type: research

Biobased flame retardants from tartaric acid and derivatives
Publication date: Available online 12 October 2018Source: Polymer Degradation and StabilityAuthor(s): Bob A. Howell, Wenxiao SunAbstractBiobased flame retardants represent attractive alternatives to traditional organohalogen compounds which are persistent in the environment, tend to bioaccumulate and may pose risks to human health. Tartaric acid is generated annually in great abundance as a by-product of wine making. It is nontoxic and widely used as a food ingredient. It is tetrafunctional which provides broad opportunity for conversion to a wide spectrum of useful materials. It has been used as a base for the generation ...
Source: Polymer Degradation and Stability - October 14, 2018 Category: Chemistry Source Type: research

Influence of network structure on the degradation of poly(ether)amine-cured epoxy resins by inorganic acid
Publication date: Available online 11 October 2018Source: Polymer Degradation and StabilityAuthor(s): Jonathon D. Tanks, Masatoshi Kubouchi, Yoshihiko AraoAbstractIn this paper, we investigate the case of bisphenol-type epoxy crosslinked with poly(ether)amine, immersed in sulfuric acid at elevated temperature. The results show that very high equilibrium mass-change (up to 40%) is observed, and that amine protonation is largely responsible for this behavior. When the acid solution concentration is 5mass% or higher, alcohol dehydration and aromatic ether cleavage reactions occur by excess acid (after amine protonation). A me...
Source: Polymer Degradation and Stability - October 12, 2018 Category: Chemistry Source Type: research

Pyrolysis mechanism of Poly(lactic acid) for giving lactide under the catalysis of tin
Publication date: Available online 9 October 2018Source: Polymer Degradation and StabilityAuthor(s): Lidong Feng, Songyang Feng, Xinchao Bian, Gao Li, Xuesi ChenAbstractIn order to obtain the mechanisms of the pyrolysis reaction that poly (lactic acid) (PLA) gives lactide in the presence of Sn, the four types of low molecular weight PLAs (L-PLA) with different end-groups were prepared, including HO-L-PLA-COOH, R-L-PLA-OH, R-L-PLA-COOH, and R-L-PLA-R, and depolymerized by thermogravimetry at different heating rates. As for the pyrolysis reactions of the L-PLAs, their activation energy (Ea) were estimated by the several isoc...
Source: Polymer Degradation and Stability - October 11, 2018 Category: Chemistry Source Type: research

Facile melt processing technique for the preparation of super ductile PLA–PEG multiblock copolymers: The roles of catalyst and antioxidant loadings
Publication date: Available online 9 October 2018Source: Polymer Degradation and StabilityAuthor(s): Wasin Koosomsuan, Pranee Phinyocheep, Kalyanee SirisinhaAbstractThe unprecedented use of chain-scission reaction to constitute a facile and one-pot approach for the preparation of multiblock copolymers consisting of poly(lactic acid) (PLA) and poly(ethylene glycol) (PEG) from high molecular weight PLA was demonstrated. This involves two consecutive steps including melt transesterification (1) of PLA with PEG catalyzed by nontoxic titanium-based catalyst in an internal mixer to form short-chain block copolymers, followed by ...
Source: Polymer Degradation and Stability - October 11, 2018 Category: Chemistry Source Type: research

Chain extension of poly (butylene adipate-co-terephthalate) and its microcellular foaming behaviors
Publication date: Available online 9 October 2018Source: Polymer Degradation and StabilityAuthor(s): Jingsi Song, Jianguo Mi, Hongfu Zhou, Xiangdong Wang, Yuxia ZhangAbstractA facile chain extension and solid-phase batch foaming method was proposed to prepare microcellular poly (butylene adipate-co-terephthalate) (PBAT) foams in the presence of supercritical CO2. Branching structure and micro cross-linking structure were generated in modified PBAT with styrene-acrylonitrile-glycidyl methacrylate terpolymer (SAG) as chain extender, which was confirmed by Fourier transform infrared spectra, gel permeation chromatography and ...
Source: Polymer Degradation and Stability - October 9, 2018 Category: Chemistry Source Type: research

Bio-inspired engineering of boron nitride with iron-derived nanocatalyst toward enhanced fire retardancy of epoxy resin
Publication date: Available online 9 October 2018Source: Polymer Degradation and StabilityAuthor(s): Zhi Li, Sara Isabel Montero Lira, Lu Zhang, Daniel Fernández Expósito, Vignesh Babu Heeralal, De-Yi WangAbstractAiming at improving fire retardancy of epoxy resin (EP), the thermal-exfoliated boron nitride nanosheets (BN) underwent the bio-inspired polydopamine (PDA) nano-coating and in-situ interfacial growth of iron-derived nanocatalyst (Fe) to prepare nanohybrid (BN@PDA@Fe). The design complied with principles: 1) PDA promoted the dispersion of BN in EP matrix and offered active sites for functionalization ...
Source: Polymer Degradation and Stability - October 9, 2018 Category: Chemistry Source Type: research

Degradation and related changes in supermolecular structure of poly(caprolactone) in vivo conditions
Publication date: November 2018Source: Polymer Degradation and Stability, Volume 157Author(s): P. Sajkiewicz, M.K. Heljak, A. Gradys, E. Choińska, S. Rumiński, T. Jaroszewicz, I. Bissenik, W. ŚwięszkowskiAbstractThe degradation in vivo and its effect on the supermolecular structure of poly(caprolactone) was examined. Poly(caprolactone) (PCL) samples were prepared in the form of porous scaffolds implanted into rat calvarial defects. The degradation was investigated by means of gel permeation chromatography, wide angle X-ray scattering (WAXS), scanning electron microscopy (SEM) and differential scanning calorimetry ...
Source: Polymer Degradation and Stability - October 7, 2018 Category: Chemistry Source Type: research

Editorial Board
Publication date: October 2018Source: Polymer Degradation and Stability, Volume 156Author(s): (Source: Polymer Degradation and Stability)
Source: Polymer Degradation and Stability - October 6, 2018 Category: Chemistry Source Type: research

Processing, thermo-mechanical characterization and gas permeability of thermoplastic starch/poly(butylene trans-1,4-cyclohexanedicarboxylate) blends
Publication date: Available online 5 October 2018Source: Polymer Degradation and StabilityAuthor(s): Laura Genovese, Franco Dominici, Matteo Gigli, Ilaria Armentano, Nadia Lotti, Elena Fortunati, Valentina Siracusa, Luigi Torre, Andrea MunariAbstractIn this contribution, binary blends of thermoplastic starch (TPS) and poly(butylene trans-1,4-cyclohexanedicarboxylate) (PBCE) have been prepared by melt extrusion. The effect of different amounts of PBCE and the presence of citric acid as compatibilizer have been studied with respect to the blend behavior. In particular, morphological and thermal studies allowed for the determ...
Source: Polymer Degradation and Stability - October 6, 2018 Category: Chemistry Source Type: research

Accelerated aging of polyethylene pipe grades in aqueous chlorine dioxide at constant concentration
Publication date: Available online 24 September 2018Source: Polymer Degradation and StabilityAuthor(s): M. Bredács, A. Frank, A. Bastero, A.Stolarz, G. PinterAbstractThe impact of disinfected water on the degradation of polyethylene (PE) was investigated with immersion tests of two PE pipe materials in 10 and 5 ppm chlorine dioxide (ClO2) medium at 60 °C. Aging experiments in 1 ppm ClO2 at 60, 50 and 40 °C were also carried out to study the effect of different aging temperatures. During conditioning, the pH was kept at 6.8. A specific exposure device with continuous concentration control and adjustme...
Source: Polymer Degradation and Stability - October 5, 2018 Category: Chemistry Source Type: research

Impact of thermal oxidation of polymers on features of fluorescent probes
Publication date: Available online 26 September 2018Source: Polymer Degradation and StabilityAuthor(s): Géraldine Rapp, Eric-Aimé Poutougnigni, Jean-Luc Gardette, Pierre-Olivier Bussiere, Sandrine TheriasAbstractThe aim of this work was to evaluate the potential of 2-dimethylamino-6-propionylnaphthalene (denoted Prodan®) as a sensitive fluorophore for monitoring the oxidation of polymers at low extent of oxidation within the “induction period” and for characterizing the chemical modification of polymers induced by thermal oxidation. The fluorophore was introduced into polyethylene films (85 mi...
Source: Polymer Degradation and Stability - October 5, 2018 Category: Chemistry Source Type: research

Early-stage photodegradation of aromatic poly(urethane-urea) elastomers
Publication date: Available online 26 September 2018Source: Polymer Degradation and StabilityAuthor(s): Tianlong Zhang, Fengwei Xie, Julius Motuzas, Peter Bryant, Valsala Kurusingal, John M. Colwell, Bronwyn LaycockAbstractThe photooxidative stability of an aromatic segmented poly(urethane-urea) (PUU) elastomer, stabilised with a range of carbon black fillers, was assessed after very low UVA doses as a means to identify components that are highly susceptible to UV degradation, and suggest better design of such materials. Fourier-transform infrared (FTIR) analysis indicated rapid degradation of the urea bonds in the hard se...
Source: Polymer Degradation and Stability - October 5, 2018 Category: Chemistry Source Type: research

Degradation and related changes in supermolecular structure of poly(caprolactone) in vivo conditions
Publication date: Available online 1 October 2018Source: Polymer Degradation and StabilityAuthor(s): P. Sajkiewicz, M.K. Heljak, A. Gradys, E. Choińska, S. Rumiński, T. Jaroszewicz, I. Bissenik, W. ŚwięszkowskiAbstractThe degradation in vivo and its effect on the supermolecular structure of poly(caprolactone) was examined. Poly(caprolactone) (PCL) samples were prepared in the form of porous scaffolds implanted into rat calvarial defects. The degradation was investigated by means of gel permeation chromatography, wide angle X-ray scattering (WAXS), scanning electron microscopy (SEM) and differential scanning calorimetry...
Source: Polymer Degradation and Stability - October 5, 2018 Category: Chemistry Source Type: research

Synthesis and application of a benzoxazine-type phosphorus-containing monomer on epoxy/benzoxazine copolymer: Thermal stability and compatibility with liquid oxygen
Publication date: Available online 2 October 2018Source: Polymer Degradation and StabilityAuthor(s): Cong Peng, Chang Gao, Yuhuan Yuan, Zhanjun Wu, Dayu zhouAbstractAlkene-terminated monofunctional benzoxazine monomer (A-BA) was synthesized using allylamine, phenol and paraformaldehyde. Subsequently, the phosphorous-containing benzoxazine monomer (PBA) was obtained through the addition reaction between 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and A-BA in toluene. Finally, epoxy/benzoxazine copolymer with chemically-bonded DOPO was prepared using the synthesized PBA as hardener of DGEBA. DMA results showed...
Source: Polymer Degradation and Stability - October 5, 2018 Category: Chemistry Source Type: research

Discoloration of poly(vinyl acetate) (PVAc) gluelines in wood assemblies
Publication date: Available online 2 October 2018Source: Polymer Degradation and StabilityAuthor(s): Fabio Chiozza, Ilaria Santoni, Benedetto PizzoAbstractThe bondline chromatic alteration of poly(vinyl acetate) (PVAc) in wood assemblies has an appreciable impact on the aesthetic characteristic of these products (mostly important for panels used in furniture). While the origin of this phenomenon has been explained for the cases of pure polymers and wood substrates alone, present work investigates about the origin of discoloration for the case of bondlines prepared with selected wood species (cherry and maple) and two comme...
Source: Polymer Degradation and Stability - October 5, 2018 Category: Chemistry Source Type: research

Synergistic crosslink of double bond and nitrile group of nitrile rubber in H2S environment
This study investigated the corrosion test of nitrile-butadiene rubber (NBR) in H2S. Butadiene rubber (BR) and hydrogenated nitrile-butadiene rubber (HNBR) were used to simulate the structural units of 1,4-polybutadiene and polyacrylonitrile in NBR. The characterizations of infrared spectra, CHNS elemental analysis, and XPS may indicate that when double bonds and nitrile groups coexist, NBR has the highest reactivity with H2S and crosslinks of monosulfur and disulfide appear inside the rubber. However, the reactivity of BR and HNBR was reduced and no crosslinking was produced when both were isolated. Therefore, double bond...
Source: Polymer Degradation and Stability - October 5, 2018 Category: Chemistry Source Type: research

A weak infrared light strengthens anoxygenic photosynthetic bacteria activated sludge for the anaerobic biodegradation of polylactic acid in microbial fuel cell systems
This study explored that a weak infrared (IR) (850 nm) light emitting diode (LED) strengthened anoxygenic photosynthetic bacteria (APB) activated sludge for the anaerobic biodegradation of PLA in MFC systems. The results showed that MFC system with IR and PLA could generate a sustained bioelectricity and achieve the anaerobic biodegradation of PLA textiles based on bioelectrochemistry, FT-IR and SEM analysis. The microbial community structure analysis suggested that an APB consortium can be enriched using the MFC with IR illumination. Moreover, the existence of IR light could not only prevent algae growth in MFC system b...
Source: Polymer Degradation and Stability - October 5, 2018 Category: Chemistry Source Type: research

Degradation of waste polycarbonate via hydrolytic strategy to recover monomer (bisphenol A) catalyzed by DBU-based ionic liquids under metal- and solvent-free conditions
Publication date: November 2018Source: Polymer Degradation and Stability, Volume 157Author(s): Mengshuai Liu, Jiao Guo, Yongqiang Gu, Jun Gao, Fusheng LiuAbstractThe application of ionic liquids in chemical recycling of waste polycarbonate (PC) via the simple hydrolytic strategy has shown great potential. Herein, a series of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) based ILs were facilely synthesized and characterized, and could efficiently catalyze the hydrolysis of PC in the absence of transition metal and solvent. The catalyst structures and reaction conditions were optimized, and 100% PC conversion with 97% bisphenol A...
Source: Polymer Degradation and Stability - October 5, 2018 Category: Chemistry Source Type: research

Characterization of the secondary structure of degummed Bombyx mori silk in modern and historical samples
Publication date: November 2018Source: Polymer Degradation and Stability, Volume 157Author(s): Diego Badillo-Sanchez, David Chelazzi, Rodorico Giorgi, Alessandra Cincinelli, Piero BaglioniAbstractUnderstanding the degradation mechanisms of silk is essential for improving preventive conservation measures, and developing consolidation materials to restore the degraded fibers. Here, modern and historical silk samples were analyzed with an inclusive set of analytical techniques, in order to investigate the changes in the protein secondary structure that occurred upon natural aging or manufacturing processes. FTIR 2D Imaging-Ch...
Source: Polymer Degradation and Stability - October 5, 2018 Category: Chemistry Source Type: research

Use of ion-assisted sputtering technique for producing photocatalytic titanium dioxide thin films: Influence of thermal treatments on structural and activity properties based on the decomposition of stearic acid
Publication date: Available online 21 September 2018Source: Polymer Degradation and StabilityAuthor(s): V. Vishnyakov, P.J. Kelly, J. Humblot, R.J. Kriek, N.S. Allen, N. MahdjoubAbstractTitanium dioxide thin films were deposited by the reactive ion-assisted sputtering method from titanium targets at various partial pressures and deposition parameters. The films were deposited onto substrates at temperatures ranging from room-temperature conditions to 722 K. A selection of thin films was post-deposited annealed at temperatures up to 972 K for 10 min and characterized by micro-Raman spectroscopy and scanning electron m...
Source: Polymer Degradation and Stability - September 22, 2018 Category: Chemistry Source Type: research