BIDIRECTIONAL SHAPE-MEMORY POLYMER, METHOD OF ITS PRODUCTION AND ITS USE

摘要

The present invention relates to an article consisting of or comprising a bidirectional shape-memory polymer (bSMP), the bSMP comprising: first phase-segregated domains (AD) having a first transition temperature (Tt,AD) corresponding to a crystallization transition or glass transition of the first domains (AD), second phase-segregated domains (SD) having a second transition temperature (Tt,SD) corresponding to a crystallization transition or glass transition of the second domains (SD), the second transition temperature (Tt,SD) being higher than the first transition temperature (Tt,AD), and covalent or physical bonds cross-linking the polymer chains of the bSMP, and in this way interconnecting the first and second domains (AD, SD), wherein the second phase-separated domains (SD) form a skeleton which is at least partially embedded in the first phase-segregated domains (AD), and wherein polymer chain segments of the bSMP forming the first domains (AD) are substantially orientated in a common direction, such that the bSMP is able to undergo a reversible shape-shift between a first shape (A) at a first temperature (Thigh) and a second shape (B) at a second temperature (Tlow) upon variation of temperature between the first and second temperature (Thigh, Tlow) driven by the crystallization and melting or vitrification and melting of the first phase-separated domains (AD) and without application of an external stress, with Tlow < Tt,AD < Thigh < Tt,SD.