Epoxy-Modified Pyrophyllite as a Multifunctional Chain Extender for Poly(latic acid)

Pyrophyllite (Prl), an aluminosilicate with a balanced mineral structure and extremely small particle size, appears to be an ideal filler but is rarely used in polymers. Herein, a method for the application of pyrophyllite in polymers is reported. A multifunctional filler is prepared by epoxy-modified pyrophyllite and incorporated into poly(latic acid) (PLA) to enhance its processability and crystallization properties. Results show the effectiveness of epoxy-modified Prl in composite film with a significant reduction in glass transition temperature, and noteworthy increment in crystallinity and spherulite growth rate. Water vapor barrier properties of PLA composite films increase over 30% with a range of Prl Loading. Furthermore, an enhancement of the tensile strength is increased by 30% and strain at break by 337.1% for PLA composite films compared to neat PLA. This work provides a new idea to prepare the functionalized pyrophyllite fillers and a theoretical basis to develop the application of pyrophyllite for polymers.