Polymer design for high temperature shape memory: Low crosslink density polyimides

被引：93

作者：

Koerner, Hilmar ^{[1
]}

Strong, Robert J. ^{[1
]}

Smith, Matthew L. ^{[1
]}

Wang, David H. ^{[1
]}

Tan, Loon-Seng ^{[1
]}

Lee, Kyung Min ^{[1
]}

White, Timothy J. ^{[1
]}

Vaia, Richard A. ^{[1
]}

机构：

[1] Air Force Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA

来源：

POLYMER | 2013年 / 54卷 / 01期

关键词：

Shape memory; Polyimide; Nanocomposite; THERMOMECHANICAL BEHAVIOR; CONSTITUTIVE THEORY; POLYURETHANE; NETWORKS; NANOCOMPOSITES; COMPOSITES; RECOVERY; MODEL;

D O I：

10.1016/j.polymer.2012.11.007

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

Shape memory in polymers is a process whereby mechanical energy is microscopically stored, and reversibly recovered within the polymer. Consideration of the viscoelastic and glassy dynamics necessary for each step of the process reveals key molecular characteristics that may improve performance, including a rigid polymer backbone with narrow molecular weight distribution between a low fraction of crosslinks. With this insight to guide high temperature polymer design, aromatic CP2 polyimide and associated single wall carbon nanotube (SWNTs) nanocomposites are shown to have excellent shape memory performance at 220 degrees C with rapid recovery (<10 s), excellent fixity (>98%), good cyclability and outstanding creep resistance. A narrow glass transition temperature regime (<10 degrees C) and high fragility (m similar to 117) affords a narrow triggering window and the ability to spatially localize recovery with a temperature gradient. The addition of up to 3 vol% of dispersed SWNTs improves the rubbery modulus and blocking force without substantially impacting these crucial characteristics. The structure-performance relationships in this material system reinforce the key molecular characteristics for the design of polymers for shape memory. Published by Elsevier Ltd.

引用

页码：391 / 402

页数：12