Fully Biobased Shape Memory Material Based on Novel
Cocontinuous Structure in Poly(Lactic Acid)/Natural Rubber TPVs Fabricated
via Peroxide-Induced Dynamic Vulcanization and in Situ Interfacial
Compatibilization
- Publication date
- Publisher
Abstract
Shape
memory polymers (SMPs) based on fully biobased poly(lactide) (PLA)/natural
rubber (NR) thermoplastic vulcanizates (TPVs) were fabricated via
peroxide-induced dynamic vulcanization. Simultaneously, in situ reactive
compatibilization was achieved by PLA molecule grafting onto NR chains.
Differing from the general concept of spherical rubber particles being
formed after dynamic vulcanization, the cross-linked NR was found
to be a “netlike” continuous phase in the PLA matrix.
This novel structure explained the surprising shape memory property
of PLA/NR TPVs well (shape fixities ∼ 100%, shape recoveries
> 95%, and fast recovery speed < 15 s at the switching temperature,
∼60 °C): the cross-linked NR continuous phase offers strong
resilience and the PLA phase serves as the heat-control switch. We
envision that the “green” raw materials and excellent
shape memory properties of the dynamically vulcanized PLA/NR SMPs
will open up a wide range of potential applications in intelligent
medical devices