Effective stress transferring interface and mechanical property enhancement of poly(L-lactide)/multi-walled carbon nanotubes fibers

Publication date: Available online 4 June 2019Source: Materials Chemistry and PhysicsAuthor(s): Qi-hao Yu, Fan Zhu, Juan-juan Su, Jian HanAbstractThe poly(L-lactide) grafted multi-walled carbon nanotubes (MWNT-g-PLLA) was firstly prepared, and a maximum grafting amount of 31wt% was obtained by optimizing grafting reaction conditions. Then the PLLA/MWNT-g-PLLA composite fibers were fabricated by melt spinning, and showed significant enhancement of tensile strength and elongation at break, comparing with the unmodified PLLA/MWNTs or pure PLLA ones. Structure analysis of as-spun fibers revealed uniform dispersion of MWNT-g-PLLA in PLLA matrix on account of good interfacial compatibility, which could prevent premature interface damage and ensure the continuous deformation of fibers under stress. The crystal morphology of strain hardening before unbroken fibers were expressly observed, suggesting a possible stretching induced formation of nano-hybrid shish-calabash similar to structure in which the PLLA lamellae growing onto the MWNT-g-PLLA axis. This interface crystallization greatly improved the interfacial stress transferring between PLLA and MWNT-g-PLLA, thus resulted in notable promoted tensile strength and elongation at break.
Source: Materials Chemistry and Physics - Category: Materials Science Source Type: research