Interfacial confinement in semi-crystalline shape memory polymer towards sequentially dynamic relaxations.

Liu, Jingyun, Xing, Ziyu, Wang, Xiaodong, Lu, Haibao and Fu, Yong Qing (2022) Interfacial confinement in semi-crystalline shape memory polymer towards sequentially dynamic relaxations. International Journal of Applied Mechanics. ISSN 1758-8251 (In Press)

[img]
Preview
Text
ijam_final.pdf - Accepted Version

Download (931kB) | Preview

Abstract

Sequential glass and melting transitions in semi-crystalline shape memory polymers (SMPs) provide great opportunities to design and generate multiple shape-memory effects (SMEs) for practical applications. However, the complexly dynamic confinements of coexisting amorphous and crystalline phases within the semi-crystalline SMPs are yet fully understood. In this study, an interfacial confinement model is formulated to describe dynamic relaxation and shape memory behavior in the semi-crystalline SMPs undergoing sequential phase/state transitions. A confinement entropy model is firstly established to describe the glass transition behavior of amorphous phase within the SMPs based on the free volume theory, where the free volume is critically confined by the crystalline phase. An extended Avrami model is then formulated using the frozen volume theory to characterize the melting and crystallization transitions of the crystalline phase in the SMPs, whose interfacial confinement with the amorphous phase has been identified as the driving force for the supercooled regime. Furthermore, an extended Maxwell model is formulated to describe the effect of dynamic confinement of two phases on the multiple SMEs and shape recovery behaviors in the semi-crystalline SMPs. Finally, effectiveness of the newly proposed model is verified using the experimental data reported in the literature. This study aims to provide a new methodology for the dynamic confinements and cooperative principles in the semi-crystalline SMP towards multiple SMEs.

Item Type: Article
Additional Information: Funding information: This work was financially supported by the National Natural Science Foundation of China (NSFC) under Grant No. 11725208 and 12172107, and International Exchange Grant (IEC/NSFC/201078) through Royal Society and NFSC.
Uncontrolled Keywords: shape memory polymer; semi-crystalline; dynamic confinement
Subjects: F100 Chemistry
F200 Materials Science
H800 Chemical, Process and Energy Engineering
Department: Faculties > Engineering and Environment > Mathematics, Physics and Electrical Engineering
Depositing User: Elena Carlaw
Date Deposited: 07 Jan 2022 13:49
Last Modified: 07 Jan 2022 14:00
URI: http://nrl.northumbria.ac.uk/id/eprint/48099

Actions (login required)

View Item View Item

Downloads

Downloads per month over past year

View more statistics