Effect of core–shell rubber toughening on mechanical, thermal, and morphological properties of poly(lactic acid)/multiwalled carbon nanotubes nanocomposites

Abstract

The effect of core–shell rubber (CSR) toughening on mechanical and thermal properties of poly(lactic acid)/multiwalled carbon nanotubes (PLA/CNT) nanocomposites were investigated. The nanocomposites were prepared by direct melt blending method in a counter‐rotating twin‐screw extruder. The contents of CSR were varied between 5 and 20 wt % while the content of CNT was kept at 5 phr. The extruded samples were injection molded into the desired test specimens for mechanical and thermal properties analysis. The impact strength of PLA/CNT increased with increasing CSR content with concomitant decrease in tensile strength and modulus. Interestingly, the flexural strength increased at low CSR content before decreasing at 15 and 20% content. Differential scanning calorimetry analysis on the second heating cycle shows no crystallinity content for PLA/CNT and all CSR toughened PLA/CNT nanocomposites, while thermogravimetric analysis shows lower thermal degradation of all CSR toughened PLA/CNT as compared to PLA/CNT nanocomposite. This study reveals significant correlation between CSR loading with the mechanical and thermal properties of the nanocomposites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47756.

Toughened Poly(lactic acid)/BEP Composites with Good Biodegradability and Cytocompatibility

“…Both crazing initiation and crazing extension can consume energy. Accordingly, the polymer absorbs a high amount of energy and avoids a highly localized strain process, which leads to higher elongation at break and impact strength [37,38]. On the other hand, crazing extension will terminate when they meet with some other BEPs, thereby preventing the generation of cracking in the PLA matrix and increasing the toughness of the PLA/BEP composites [39].…”

Thermal, Dynamic Mechanical Analysis and Mechanical Properties of Polybutylene Terephthalate/Polyethylene Terephthalate Blends

“…Since there is no known value of ∆Ho of the PBT/PET blends, the Xc of each blend are calculated separately corresponding to PBT and PET individually. The calculation of Xc is presented in Equation 1 [20].…”

Stereocomplex Crystallization Induced Significant Improvement in Transparency and Stiffness–Toughness Performance of Core‐Shell Rubber Nanoparticles Toughened Poly(l‐lactide) Blends

“…[ 21–23 ] Compared with the complex interfacial modification methods of reactive compatibilizing or synthesizing copolymer compatibilizers, in recent years, toughening PLLA with core‐shell rubber nanoparticles has attracted much more attention due to their good interfacial modification effect, low cost, and easy industrialized production. [ 24–31 ] Generally, core‐shell rubber nanoparticles contain a cross‐linked rubbery core to enhance the toughness of polymer and a hard plastic shell (grafted to the rubbery core) to impart good compatibility to polymer/rubber blend and then improve interfacial interaction. [ 27–32 ] The prominent feature of core‐shell rubber nanoparticles is that their particle size, composition, structure, and morphology can be designed and controlled according to the requirements, and moreover, these characters are unaffected by the melt‐processing procedures.…”

“…[ 24–31 ] Generally, core‐shell rubber nanoparticles contain a cross‐linked rubbery core to enhance the toughness of polymer and a hard plastic shell (grafted to the rubbery core) to impart good compatibility to polymer/rubber blend and then improve interfacial interaction. [ 27–32 ] The prominent feature of core‐shell rubber nanoparticles is that their particle size, composition, structure, and morphology can be designed and controlled according to the requirements, and moreover, these characters are unaffected by the melt‐processing procedures. [ 28–30,32 ] In this respect, utilizing core‐shell rubber nanoparticles to toughen PLLA can provide favorable conditions for solving the problems that lie in the rubber toughened PLLA blends, like weak interfacial attraction, the contradiction between transparency and mechanical properties, and the regulation of the structure and properties of PLLA/rubber blends.…”