Synergistic Effects of Nucleating Agents and Plasticizers on the Crystallization Behavior of Poly(lactic acid)

Molecules

Xuetao Shi¹  Guangcheng Zhang¹  Thanh Vu Phuong²  Andrea Lazzeri² 

[1] Department of Applied Chemistry, School of Science, Northwestern Polytechnical University, 127# Youyi XiLu, Xi’an 710072, China; E-Mail:;Department of Chemical Engineering, Industrial Chemistry and Materials Science, University of Pisa, via Diotisalvi 2, Pisa 56126, Italy; E-Mail:

关键词: poly(lactic acid);    nanoparticles;    particle-reinforced composites;    synergism;   

DOI  :  10.3390/molecules20011579

来源: mdpi

【 摘 要 】

The synergistic effect of nucleating agents and plasticizers on the thermal and mechanical performance of PLA nanocomposites was investigated with the objective of increasing the crystallinity and balancing the stiffness and toughness of PLA mechanical properties. Calcium carbonate, halloysite nanotubes, talc and LAK (sulfates) were compared with each other as heterogeneous nucleating agents. Both the DSC isothermal and non-isothermal studies indicated that talc and LAK were the more effective nucleating agents among the selected fillers. Poly(d-lactic acid) (PDLA) acted also as a nucleating agent due to the formation of the PLA stereocomplex. The half crystallization time was reduced by the addition of talc to about 2 min from 37.5 min of pure PLA by the isothermal crystallization study. The dynamic mechanical thermal study (DMTA) indicated that nanofillers acted as both reinforcement fillers and nucleating agents in relation to the higher storage modulus. The plasticized PLA studied by DMTA indicated a decreasing glass transition temperature with the increasing of the PEG content. The addition of nanofiller increased the Young’s modulus. PEG had the plasticization effect of increasing the break deformation, while sharply decreasing the stiffness and strength of PLA. The synergistic effect of nanofillers and plasticizer achieved the balance between stiffness and toughness with well-controlled crystallization.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.