具有“钢筋混凝土”双连续相结构的PLA/NR动态硫化共混材料的结构形成调控及其形状记忆行为研究

Polylactide (PLA) has a promising application in biomedical field due to its excellent biodegradability, nontoxicity and shape-memory effect. However, the inherent brittleness of PLA limited its shape-memory use, and moreover, the shape-memory property of neat PLA is difficult to satisfy the various applications. Therefore, modifying PLA to improve its shape-memory property and toughness is always a hot topic in the field of functional application. Differing to the typical sea-island structure, we obtained a novel phase structure in dynamically vulcanized PLA/natural rubber (NR) blend that a continuous network-like morphology structure of crosslinked NR phase throughout the PLA continuous phase, forming a “Reinforced Concrete” bi-continuous phase structure. The continuous and crosslinked NR phase had stronger elasticity which endowed PLA/NR blend excellent shape-memory behavior and super-toughness. In this project, the formation of this novel bi-continuous phase structure will be controlled to better fulfill the shape-memory behavior of dynamically vulcanized PLA/NR blends. The mechanism of shape-memory behavior will be systemic studied. This project will enrich the formation control of phase structure of blends in dynamic vulcanization and open up an avenue for designing shape-memory blend materials.

聚乳酸(PLA)具有良好的生物降解性、无毒性与形状记忆性，在生物医学领域极具应用前景。然而PLA固有的脆性限制了其形状记忆特性的施展，纯PLA的形状记忆效应亦不足以胜任各种实际应用。因此针对PLA的各种改性以提高形状记忆性能与韧性一直为功能应用领域的前沿热点。不同于经典的“海-岛”结构，我们前期基于PLA与天然橡胶(NR)动态硫化获得了类网状且交联的NR连续相贯穿在PLA连续相中，形成类似“钢筋混凝土”的双连续相结构，拥有相比分散的橡胶颗粒更强有力的回弹性，可望赋予PLA优异的形状记忆功能。本课题就此种特殊的相形貌结构对其形成演变进行调控以获得更优异的形状记忆功能，并对PLA/NR共混材料的形状记忆性能及其机理进行系统研究。项目的实施，有助于丰富动态硫化技术调控共混物形貌结构的科学研究体系，同时亦为共混型形状记忆功能材料的制备提供新思路。

聚乳酸(PLA)具有良好的生物降解性、无毒性与形状记忆性，在生物医学领域极具应用前景。然而PLA固有的脆性限制了其形状记忆特性的施展，纯PLA的形状记忆效应亦不足以胜任各种实际应用。因此针对PLA的各种改性以提高形状记忆性能与韧性一直为功能应用领域的前沿热点。不同于经典的“海-岛”结构，我们前期基于PLA与天然橡胶(NR)动态硫化获得了类网状且交联的NR连续相贯穿在PLA连续相中，形成类似“钢筋混凝土”的双连续相结构，拥有相比分散的橡胶颗粒更强有力的回弹性，赋予PLA优异的形状记忆功能。本课题就此种特殊的相形貌结构对其形成演变进行调控以获得更优异的形状记忆功能，并对PLA/NR共混材料的形状记忆性能及其机理进行系统研究。项目的实施，有助于丰富动态硫化技术调控共混物形貌结构的科学研究体系，同时亦为共混型形状记忆功能材料的制备提供新思路。l