Fast-Scan and Temperature-Modulated Calorimetry of Recrystallization of Poly(ethylene terephthalate)

Publication date: Available online 14 September 2019Source: Thermochimica ActaAuthor(s): Akihiko TodaAbstractThe recrystallization behavior of poly(ethylene terephthalate), PET, in the melting region was examined by Fast-Scan and Temperature-Modulated Calorimetry. In addition to the prior results of Fast-Scan Calorimetry, FSC, evidence that recrystallization caused double PET melting peaks was obtained. An exothermic recrystallization peak was directly observed in the second heating run of FSC after the lower-temperature melting peak was eliminated through rapid heating and cooling. FSC was then performed with a temperature protocol of a periodic step-wise jump in temperature, a mode of temperature modulated FSC, T-M FSC. A broad and large peak of the effective dynamic heat capacity of complex quantity was observed in the melting region during T-M FSC analysis, which proved that melting occurred in the temperature range between the double melting peaks. A broad negative peak in the phase angle of the dynamic heat capacity was observed in the melting region at a low underlying heating rate with long modulation periods, which indicated that recrystallization and melting occurred simultaneously.
Source: Thermochimica Acta - Category: Chemistry Source Type: research

Related Links:

Wavefront shaping makes it possible to form a focus through opaque scattering materials. In some cases, this focus may be scanned over a ...
Source: Optics Letters - Category: Physics Authors: Source Type: research
Publication date: Available online 16 October 2019Source: Biocatalysis and Agricultural BiotechnologyAuthor(s): Bahgat Fayed, Hoda S. El-Sayed, Amira Abood, Amal M. Hashem, Nayra S.H. MehannaAbstractThe potential application for the multiparticulate synbiotic microcapsule in yoghurt production was presented in the current study. Initially, three different formulae were fabricated to investigate the mechanism of action. This was followed by characterization the size of both of the nanoparticles and the final multiparticulate microcapsule. The yoghurt was then formed and the formulae were added and subjected to 4 weeks stora...
Source: Biocatalysis and Agricultural Biotechnology - Category: Biotechnology Source Type: research
In this study, new peripheral tetra-4-butylmorpholine substituted zinc(II) phthalocyanine was synthesized through C–C bond formation using the palladium catalyzed Suzuki-Miyaura coupling reaction. Its structure was characterized by elemental analysis, FT-IR, 1H NMR, 13C NMR, UV–vis, fluorescence, and MALDI-TOF-mass spectroscopic techniques. Its thermal property were evaluated by thermogravimetric analysis and differential scanning calorimetry. In addition, the photophysical properties of the zinc(II) phthalocyanine were also investigated in DMSO.
Source: Journal of Molecular Structure - Category: Molecular Biology Source Type: research
Publication date: Available online 16 October 2019Source: Process BiochemistryAuthor(s): Raedah A.S. Alatawi, M. Monier, Nadia H. ElsayedAbstractIn this work, a photo-responsive hydrogel membrane based on cinnamate-modified hyaluronic acid (HA-CM) was developed and safely cross-linked under UV light curing. The obtained material was effectively utilized for immobilization of horseradish peroxidase (HRP) enzyme via encapsulation and entrapment strategy with efficiency above 95%. The prepared HA-CM biopolymer was investigated before the UV curing using instrumental and spectral techniques including Fourier transform infrared...
Source: Process Biochemistry - Category: Biochemistry Source Type: research
Publication date: Available online 16 October 2019Source: Reactive and Functional PolymersAuthor(s): Xia Wang, Qihui Chen, Yangqing Zheng, Maochun Hong, Heqing FuAbstractFirst, Layered double hydroxide (LDH) was modified by toluene diisocyanate (TDI), 2-hydroxyethyl acrylate (HEA), and LDH-TDI-HEA was prepared. Then LDH-TDI-HEA was modified by vinyl triethoxysilane (VTES), and LDH-TDI-HEA-VTES composites were obtained. Finally, acrylate was modified by LDH-TDI-HEA-VTES, and flame retarded LDH-TDI-HEA-VTES-Acrylate composites were successfully synthesized by in situ polymerization. The structures of LDH, LDH-TDI-HEA, LDH-TD...
Source: Reactive and Functional Polymers - Category: Chemistry Source Type: research
Publication date: Available online 17 October 2019Source: PolymerAuthor(s): Subramaniyan Ramasundaram, Ashiqur Rahaman, Byungki KimAbstractA 96% β-crystalline poly(vinylidene fluoride) nanofibers (PVDF NFs) were prepared by collecting electrospun NFs on a roller operated at 5000 rpm, followed by annealing at 150 °C. Dodecylamine functionalized non-polar silver nanoparticles (Ag NPs) were synthesized. The Ag NPs were brush coated on a PVDF NFs support and used as an electrode to demonstrate a piezoelectric sensor (PS). PVDF NFs was characterized with Fourier-transform infrared spectroscopy (FTIR), X-ray diffrac...
Source: Polymer - Category: Chemistry Source Type: research
Publication date: Available online 15 October 2019Source: Microchemical JournalAuthor(s): Cong Liao, Xiao-Ru Zhao, Xin-Yu Jiang, Jie Teng, Jin-Gang YuAbstractThree-dimensional (3D) graphene oxide-pentaerythritol (GO-PER) composites with abundant oxygen-containing functional groups (such as carboxyl, hydroxyl, carbonyl, epoxy) were successfully prepared by a hydrothermal self-assembly method. The enrichment performances of GO-PER composites for rare earth elements (REEs) and phenols were investigated by batch adsorption experiments. The adsorption of REEs and phenols could reach equilibrium in 30 min and 60 min at room temp...
Source: Microchemical Journal - Category: Chemistry Source Type: research
Publication date: Available online 15 October 2019Source: Microchemical JournalAuthor(s): Hossein Abdolmohammad-Zadeh, Zahra Ayazi, Safa HosseinzadehAbstractIn this research, a solid-phase extraction (SPE) method based on application of cobalt oxide nanoparticles (Co3O4 NPs) as a novel nano-sorbent was developed for preconcentration and extraction of zinc(II) ions from various real samples followed by flame atomic absorption spectrometric (FAAS) detection. Co3O4 NPs were simply synthesized via a thermal treatment of cobalt hydroxide after a precipitation method, and its structure and morphological properties were studied b...
Source: Microchemical Journal - Category: Chemistry Source Type: research
Publication date: Available online 15 October 2019Source: Microchemical JournalAuthor(s): Mahsa N. Sheikholeslami, Maryam Vosough, Hadi M. EsfahaniAbstractLiquid chromatography triple-quadrupole mass spectrometry (LC–MS/MS) in multiple reaction monitoring (MRM) mode is a commonly used approach for quantification of target compounds in complex samples. Regarding the multivariate advantages that can be obtained in the light of full spectra recording, the potential and performance of a smart strategy which is a post-processing of LC-MS full scan data sets with multivariate curve resolution-alternating least squares (MCR...
Source: Microchemical Journal - Category: Chemistry Source Type: research
Publication date: Available online 14 October 2019Source: Microchemical JournalAuthor(s): A. Parsa, H. HeliAbstractWrinkled nanostructure of nickel was electrodeposited from a deep eutectic solvent comprising choline chloride and urea (reline) under golvanostatic conditions. Field emission scanning electron microscopic images were taken to evaluate the shape and size of the nickel nanostructure. The nickel nanostructure was then converted into the corresponding oxides, and the kinetics of charge transfer across the interface of the nanostructured oxides/an alkaline electrolyte was then studied. The electron transfer coeffi...
Source: Microchemical Journal - Category: Chemistry Source Type: research
More News: Chemistry | PET Scan