Grafting of wheat straw fibers with poly (ε-caprolactone) via ring-opening polymerization for poly(lactic acid) reinforcement

Abstract

The use of natural materials has grown in the last years in the plastics industry. Natural lignocellulose fibers derived from agricultural waste present potential to be used as a replacement for glass fibers for polymer reinforcement, leading to lower CO 2 footprint products. This work focuses on the modification of the cellulose fibers in order to improve the compatibility with poly(lactic acid) (PLA). The scoured wheat straw fibers were grafted with polycaprolactone (PCL) through ring opening polymerization. Thermal stability of the wheat straw fibers improved after chemical modifications enabling higher processing temperatures. Flexural and tensile moduli were improved by 23% and 15%, respectively, compared with neat PLA, using 20 wt% modified fibers. An improvement of 20% in the impact strength was obtained using PCL grafted fibers because of entanglements and molecular interactions between PCL grafted on the wheat straw fibers and PLA molecules.

A Review on Natural Fiber Bio-Composites, Surface Modifications and Applications

“…Polybutylene succinate (PBS), polylactic acid (PLA) [ 9 , 37 ], poly hydroxyalkanotes (PHA) [ 38 ], and poly( ε -caprolactone) (PCL) [ 39 ] are commonly used biodegradable matrices in bio-composites. Synthetic matrix materials are not biodegradable.…”

The morphological, mechanical, rheological, and thermal properties of PLA/PBAT blown films with chain extender

“…Melt‐blending PLA in an extruder with other flexible polymers is an excellent method to modify PLA. Poly(lactide acid) was blended with ductile modifiers such as poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate), poly(ε‐caprolactone), poly(butylenes succinate), and poly(butylene adipate‐co‐terephthalate) (PBAT) to make fully bio‐based and/or biocompostable materials.…”

Toughening modification of PLLA with PCL in the presence of PCL‐b‐PLLA diblock copolymers as compatibilizer

“…In order to obtain PLLA/PCL blends with high toughness, several strategies had been employed to improve the compatibility between PLLA and PCL . Reactive blending was an effective route to enhance compatibility for PLLA/PCL blends through using lysine triisocyanate or dicumyl peroxide, because the PLA‐based block or graft polymers were directly obtained in the process .…”

“…[23][24][25] In order to obtain PLLA/PCL blends with high toughness, several strategies had been employed to improve the compatibility between PLLA and PCL. [26][27][28][29][30] Reactive blending was an effective route to enhance compatibility for PLLA/PCL blends through using lysine triisocyanate or dicumyl peroxide, because the PLA-based block or graft polymers were directly obtained in the process. 26,27 Tensile toughness of these blends was significantly enhanced through reactive processing, but the application of these blends was limited in the fields with high biomedical safety requirements, because of possible toxicities derived from the residual triisocyanate incorporated.…”