In Situ Constructed Nanocrystal Structure and Its Contribution in Shape Memory Performance of Pure Polylactide

Abstract

Crystal size plays an essential role in the performance of polymers. Generally, direct processing of common spherulites into nanocrystals (NCs) is hardly applied since polymer spherulites always shape into fibrous crystals and are hard to flow again. In this study, polylactide (PLA) lamellae of spherulites are first diluted by amorphous PLA. Then, PLA NCs are constructed in situ by intense stress, which is transferred by the amorphous polylactide in a high elastic state. The NCs and their network formed in bulk endow pure polylactide with excellent shape memory features. A strong shape recovery initiation force (around 4−5 MPa) and an enhancement of 41.6% in the shape recovery ratio with 30 wt % NCs in PLA are achieved compared with traditional PLA. This study presents a new common methodology for the industrial production of polymer NCs.

Highly Efficient Dispersion of Individual Multiwalled Carbon Nanotubes by Polylactide in High Elastic State

“…A conventional two-roll mill is used to apply adequate flow stress and strain. The similar method was used to separate spherulites to nanocrystals in our previous work . The debundling of primary agglomerates and the dispersion of individual MWCNTs at different contents (up to 30 wt %) are studied.…”