Zhang Dawei, Giese Melissa L, Prukop Stacy L, Grunlan Melissa A
Department of Biomedical Engineering, Material Science and Engineering Program, Texas A&M University, College Station, TX 77843.
J Polym Sci A Polym Chem. 2011 Feb 1;49(3):754-761. doi: 10.1002/pola.24488. Epub 2010 Dec 16.
Thermoresponsive shape memory polymers (SMPs) are stimuli-responsive materials that return to their permanent shape from a temporary shape in response to heating. The design of new SMPs which obtain a broader range of properties including mechanical behavior is critical to realize their potential in biomedical as well as industrial and aerospace applications. To tailor the properties of SMPs, "AB networks" comprised of two distinct polymer components have been investigated but are overwhelmingly limited to those in which both components are organic. In this present work, we prepared inorganic-organic SMPs comprised of inorganic polydimethyl-siloxane (PDMS) segments of varying lengths and organic poly(ε-caprolactone) (PCL) segments. PDMS has a particularly low T(g) (-125 °C) which makes it a particularly effective soft segment to tailor the mechanical properties of PCL-based SMPs. The SMPs were prepared via the rapid photocure of solutions of diacrylated PCL(40)-block-PDMS(m)-block-PCL(40) macromers (m = 20, 37, 66 and 130). The resulting inorganic-organic SMP networks exhibited excellent shape fixity and recovery. By changing the PDMS segment length, the thermal, mechanical, and surface properties were systematically altered.
热响应形状记忆聚合物（SMPs）是一种刺激响应材料，可在加热时从临时形状恢复到永久形状。设计具有更广泛性能（包括机械性能）的新型SMPs对于实现其在生物医学以及工业和航空航天应用中的潜力至关重要。为了定制SMPs的性能，由两种不同聚合物组分组成的“AB网络”已被研究，但绝大多数仅限于两种组分均为有机组分的情况。在本工作中，我们制备了由不同长度的无机聚二甲基硅氧烷（PDMS）链段和有机聚（ε-己内酯）（PCL）链段组成的无机-有机SMPs。PDMS具有特别低的玻璃化转变温度（T(g)）（-125°C），这使其成为定制基于PCL的SMPs机械性能的特别有效的软链段。通过对二丙烯酸化的PCL(40)-嵌段-PDMS(m)-嵌段-PCL(40)大分子单体（m = 20、37、66和130）溶液进行快速光固化来制备SMPs。所得的无机-有机SMP网络表现出优异的形状固定性和恢复性。通过改变PDMS链段长度，热性能、机械性能和表面性能被系统地改变。
