生物基腰果酚的官能化与聚乳酸高性能化应用基础研究

Polylactic acid (PLA) is a plant derived and degradable polymer material. It has great significance for the harmonious development of human and nature, but its crystallization rate is slow and its toughness is not good. Cardanol has the characteristics of phenolic and aliphatic compounds. When applying cardanol into PLA, a new biobased materials with high performance could be found. The following problems remain to be solved in the current research: 1) how to realize the functionalization of cardanol and improve its reactivity with PLA, thereby improving the compatibility between the two phases; 2) the internal relationship between structure, process and properties of PLA modified by cardanol has not been clearly identified yet..The project starting from the chemical structure of cardanol, intends to focus on: 1) preparing of functionalized cardanol by the method of epoxidation, alcoholization and enzymatic polymerization, studying on cardanol structure and reaction activity on compatibility with PLA, by reactive blending; 2) force field and temperature field under the conditions of the cardanol functionalized /PLA blend process study, changes of sample mechanical properties, thermal stability, crystallization behavior, morphology, structure and material of the basic construction of the relationship between process performance, new technology, this paper presents a new method for preparing high performance PLA materials; 2) researching the influence of force field and temperature field of blending process on sample mechanical properties, thermal stability, crystallization behavior, morphology, establishing the relationship of structure, processing and performance, presenting new method, new technology for preparing high performance PLA materials.

聚乳酸（PLA）是一种植物来源且具有可降解特性的高分子材料，对于人与自然的和谐发展具有重要意义，但是结晶速率慢，韧性不佳。腰果酚具有酚类化合物的特征和脂肪族化合物的柔性，将其用于PLA共混改性，有望制备新型生物基高性能材料。目前的研究尚存在以下问题有待解决：1）如何实现腰果酚的官能化并提高其与PLA的反应活性，进而提高二者相容性；2）尚未明确腰果酚改性PLA材料的结构-工艺-性能的内在联系。.本项目从腰果酚的化学结构特点出发，拟重点开展：1）环氧化、多元醇化、酶促聚合等手段，制备多种官能化腰果酚，采用反应共混的方式，研究腰果酚结构及反应活性变化对相容性影响规律；2）研究官能化腰果酚/PLA共混过程中在外力场、温度场等条件下，样品力学性能、热稳定性、结晶行为、微观形貌等的变化规律，构建材料基本的结构-工艺-性能关系，提出制备高性能PLA材料的新方法、新工艺。

本项目以腰果酚为起始原料，通过化学修饰官能化腰果酚，使其具有新的反应活性，然后与聚乳酸熔融共混，使官能化的腰果酚与聚乳酸发生界面反应，或者在相应催化剂或外在条件下促进其与聚乳酸的界面反应，生成与聚乳酸具有良好相容性的共聚物，以及改进的微观结构形貌，研究在熔融共混过程中的工艺条件对反应活性、分散状态及相容性、结构演变影响。.研究团队开展了三方面的研究工作。在“聚乳酸/腰果酚反应增容共混体系”研究工作中，添加不同含量的过氧化二异丙苯引发聚乳酸与腰果酚的接枝反应，并对共混物力学性能、热性能进行表征。当在共混物中引入过氧化二异丙苯时，只需15wt.%腰果酚即可显著提高缺口冲击强度至65kJ/m2。根据热行为测试结果，腰果酚接枝到聚乳酸链上可能是在较少腰果酚含量的情况下提高冲击强度的原因。.在“聚乳酸/亚麻纤维/腰果酚(或环氧化腰果酚)共混体系”研究工作中，环氧化腰果酚对聚乳酸/亚麻纤维共混物具有较好的增韧效果。聚乳酸/亚麻纤维/环氧化腰果酚(80/10/10 )共混物的缺口冲击强度达到10.42±0.61kJ/m2，是聚乳酸/亚麻纤维(90/10)共混物(5.18±0.23kJ/m2)的2倍。聚乳酸/亚麻纤维/环氧化腰果酚( 85/5/10)共混物的断裂伸长率提升至43.76±8.58%，是聚乳酸/亚麻纤维(95/5)共混物(9.94±1.65%)的4倍以上。由环氧化腰果酚引起的界面相容性的改善被认为是韧性优异的原因。.在“腰果酚基聚氨酯”研究工作中，将腰果酚原料的酚羟基通过化学反应依次环氧化、水解，制备成腰果酚二元醇，再与二异氰酸酯加成聚合，制备出不同结构的腰果酚基聚氨酯，有望用于增韧聚乳酸。.通过以上研究工作，为进一步利用腰果酚增韧聚乳酸材料打下了理论基础。