Linear Shape Memory Polyester with Programmable Splitting of Crystals. Issue 10 (20th June 2021)

• Record Type: Journal Article
• Authors: Zhou, Ziting; Meng, Yue; Wei, Cong; Bai, Ying; Wang, Xiaoying; Quan, Daping; Zhou, Jing
• Is Part Of: Macromolecular materials and engineering. Volume 306:Issue 10(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-06-20
• Subjects: crystallization -- polyesters -- shape memory materials; Plastics -- Periodicals; Polymers -- Periodicals; Polymerization -- Periodicals; 547.705
• DOI: 10.1002/mame.202100254
• Languages: English
• ISSNs: 1438-7492

Abstract

Abstract: Shape memory polymers (SMPs)are widely used owing to their ability to change shapes under external stimuli. Conventional covalently crosslinked SMPs have limitations in biomedical applications. This article presents a linear shape memory biodegradable polyester without chemical crosslinks or multiblock structures. A new programming protocol is developed to split the crystals into two parts with different melting transitions through partial melting/recrystallization. The split crystals play different roles in fixation and recovery process to complete a shape memory cycle. The ratio between the partitioned crystals affects the fixed rate and recovery rate. The shape memory performance can be optimized by controlling the partial melting temperature and pre‐stretching of the sample. Examples of complicated shape changes demonstrate the effectiveness of the proposed technique. The method is applicable to crystallizable linear polymers and has potential applications in implantation devices. Abstract : A biodegradable linear polymer displays shape memory transition through novel programming protocol of partial melting/recrystallization. The crystals are split into different parts with different melting points. The molten/recrystallized polymer chains act as switches while the unmolten crystals memorize the original shape. The partition between the two parts is controllable for optimization of shape shifting performance.