Poly(lactic acid)/vermiculite-g-polyisoprene nanocomposites based on thiol-ene click chemistry: performance, shear crystallization and Rheonaut technology analysis

Vermiculite (VMT) grafted polyisoprene (PIP) (VMT-g-PIP) was synthesized by thiol-ene click chemistry. An orthogonal experiment and range analysis showed that the optimum reaction parameters of VMT-g-PIP were as follows: reaction time 9 h, reaction temperature 60 degrees C, initiator azodiisobutyronitrile dosage 0.025 g and mass ratio of isoprene to VMT-SH 3:1. Due to the strong interfacial compatibility between poly(lactic acid) (PLA) and VMT-g-PIP, the impact strength and elongation at break of PLA/VMT-g-PIP (0.7 wt%) nanocomposites were increased by 1.33 and 5.20 times, respectively, compared with pure PLA. Thermogravimetric analysis and cone calorimeter analysis demonstrated that the thermal stability and fire resistance effect of PLA/VMT-g-PIP nanocomposites had been improved to a certain extent. Differential scanning calorimetry and Rheonaut technology for simultaneous rheometry and Fourier transform infrared spectroscopy demonstrated that the synergistic effect of shear field and heterogeneous nucleation of VMT-g-PIP induced faster crystallization of PLA. Accordingly, the crystallization properties of PLA were clearly improved, which enhanced its toughness. Enzymatic degradation behavior showed that VMT-g-PIP inhibited the biodegradation of PLA to a certain extent. (c) 2021 Society of Industrial Chemistry.

Automated summary

VMT-g-PIP nanocomposites were synthesized by thiol-ene click chemistry, enhancing the impact strength and elongation at break of PLA, improving thermal stability and fire resistance, accelerating crystallization of PLA, improving toughness, and inhibiting the biodegradation of PLA.