界面相容剂在塑料合金及塑料填充改性中具有极为重要的界面改性作用,是聚合物共混、 塑料合金设计的关键,特别是反应型界面相容剂,由于分子链中引入了可与基体相反应的官 能团,共混时添加少量便可极大地提高界面改性效果。反应型界面相容剂多为反应性单体, 如马来酸酑、丙烯酸等接枝改性的聚烯烃,目前此类界面相容剂多采用是熔融挤出法制备, 但此方法普遍存在接枝支链短、接枝率低、加工过程中聚合物降解严重并伴有交联等问题, 因而严重影响了界面相容剂的界面改性效果和界面相容剂本身的力学性能。溶液法则由于在 溶液均相体系中进行自由基接枝聚合,反应温度远低于聚合物熔融温度,加之溶剂的隔离保 护作用,极大地减少了聚合物因高温、氧气等因素引起的降解;并且溶液体系较之于熔融体 系最大的优点在于溶剂化作用削弱了聚合物大分子间的相互作用,使得分子间距增大,更有 利于单体等小分子的扩散,提高了接枝过程中单体小分子与大分子自由基的碰撞几率,使接枝反应进行得更均匀、充分,而且溶液体系黏度较熔融体系低得多,热量传递和物料混合都 更容易实现,因而溶液法制得的界面相容剂的接枝率比熔融法高。
The interfacial compatibilizer has a very important interfacial modification in plastic alloy and plastic filling modification, which is the key to the design of polymer blending and plastic alloy, especially the reactive interface compatibilizer. Because of the introduction of the functional groups that can react with the matrix in the molecular chain, the addition of a small amount can greatly improve the interface modification. Sexual effect. Reactive monomers are reactive monomers, such as polyolefin, such as maleic acid, acrylic acid, etc., and most of these interfacial compatibilizer is prepared by melt extrusion. However, there are many problems such as short grafting chain, low grafting rate, serious degradation of polymer during processing and cross-linking. The interface modification effect of interface compatibilizer and mechanical properties of interface compatibilizer are seriously affected. The solution rule, due to the free radical grafting polymerization in the solution homogeneous phase system, is much lower than the melting temperature of the polymer and the isolation and protection of the solvent, which greatly reduces the degradation of the polymer due to high temperature and oxygen, and the solution system has the greatest advantage over the melting system because of the solvation. The interaction between macromolecules is weakened, and the interaction between large molecules is increased, the diffusion of the monomers and other small molecules is increased, the collision probability of small molecules with large molecular free radicals in the grafting process is improved, and the grafting reaction is more uniform and sufficient, and the viscosity of the solution system is much lower than that of the molten system. Heat transfer and material mixing are easier to achieve, so the grafting ratio of the interfacial compatibilizer prepared by solution is higher than that of melting method.