天然胶乳中蛋白质和磷脂对橡胶分子结构的影响

The Effect of Protein and Phospholipid on Natural Rubber Latex Molecular Structure

采用碱性蛋白酶和磷脂酶处理天然胶乳,制备脱蛋白胶乳和脱脂胶乳,结合原子吸收光谱仪、核磁共振交联密度仪、凝胶色谱(GPC)等仪器对处理前后的天然胶乳进行了分析。通过对比分析,发现酶处理后胶乳分子量降低,分子量分布变宽,金属离子浓度、凝胶含量和交联密度均降低。结果表明,金属离子与天然橡胶中的蛋白质、磷脂间存在着物理的或化学的作用力;蛋白质、磷脂在天然橡胶中起到节点的作用,有利于形成分子间交联,增大天然橡胶分子量,形成分子间网络结构。

Natural rubber latex was firstly treated with alkaline protease or phospholipase.Then the effect of protein and phospholipid on natural rubber molecular structure was investigated by the combination of atomic absorption spectroscopy,nuclear magnetic resonance crosslinking density meter and gel permeation chromatography.The results indicated that the molecular weight,molecular weight distribution,the concentration of metal ions and crosslinking density,and the gel content of natural rubber presented a significant decrease after the treatment with alkaline protease or phospholipase,which are due to that there exist physical forces or chemical bond between the metal ions and protein,phospholipid in the natural rubber.The presence of protein and phospholipid contributes to the formation of intermolecular cross-linking,increasing molecular and intermolecular network structure.