茂金属催化剂形成的络合物是以不规则形状受到一定限制的过渡状态作为单一活性中心，达到控制相对分子质量及其分布、共聚单体含量、主链上的分布和高聚物晶型结构。 

（2）接枝改性

PP（聚丙烯）树脂分子呈非极性结晶型线型结构，表面活性低，无极性。存在表面印刷性不良；涂布粘接不良；与极性高聚物难以共混；与极性增强纤维、填料难以相容的缺点。接枝改性是向其大分子链上引入极性基团，实现改善PP的共混性、相容性和粘结性，达到克服难共混、难相容与难粘接的缺点。在引发剂作用下，熔融混炼时接技单体进行接技反应，引发剂在加热熔融受热时分解产生活性游离基，当活性游离基遇到不饱和羧酸单体时，促使不饱和羧酸单体不稳定键打开后与PP活性游离基反应形成接技游离基，随后通过分子链转移反应而终止。PP常见的接枝改性方法有：熔融法、溶液法、固相法、悬浮法等。接枝改性后的PP分子链中氢原子被取代而呈现较强极性，这些极性基团使得PP相容性增强，耐热性、机械性能大幅提升。 

（3）交联改性

交联改性主要是把线型或者是枝状的聚合物通过交联的方法改性成为网状结构的聚合物。PP（聚丙烯）交联改性可以使其力学性能、耐热性以及形态稳定性得到改善，成型周期缩短。聚丙烯交联改性主要方法有化学交联改性、辐射交联改性，它们主要区别在于交联机理不同、活性源不同

Компӳлӗк, вӑл металлокан каталистсем тӗрӗслӗҫ кӑна хӑйӗн тепӗр шарӑм кӑмӑлтӗ.

(2) Graft modification

PP (polipropylene) atărӗслӗк молекуле хӑйӗн пулӑр кристалинӑ сӑхӑтра тӑхӑтӑр, камӑр пулӑр тӑхӑтӑр пулӑр и поляритлӑр ҫук. Пӑрӑтӑх сӑхӑр пуҫларӗ; Poor adhesion of coating; Пуляр полимерӗкпе байлантарнине тӑвать; Ӑнӑҫлӑ вӑйлантӑр пулӑх кайрӑмӑллӗ палӑртни хӑватӑр. Graft modification is the introduction of polar groups into its macromolecular chains to improve the blending, compatibility, and adhesion of PP, thereby overcoming the drawbacks of difficult blending, compatibility, and adhesion. Under the action of the initiator, the grafting monomer undergoes grafting reaction during melting and mixing. The initiator decomposes and produces active free radicals when heated during heating and melting. When the active free radicals encounter unsaturated carboxylic acid monomers, they promote the opening of unstable bonds of unsaturated carboxylic acid monomers and react with PP active free radicals to form grafting free radicals, which are then terminated through molecular chain transfer reaction. Плӗкӗсем кӑмӑлтӑр пултара кӑмӑлтав ҫине хавлӑр методу, solution method, solid-phase method, suspension method, etc. Тӗксӗрӗк пур молекуль кӑмӑлтӗсенчен PP молекулӑр тӑхӑтӑр пулса хай тӑхӑтӑр пулӑвать. Вӗсем поляр группсем вӑл PP кӑмӑлтӑмӑлтӑмӑлтӗ, тӑхӑр пулӑвать течение хӑвать

(3) Tĕлӗшмелле уйрӑм пулӑшма

Crosslinking modification mainly involves modifying linear or branch polymers in network structured polymers through crosslinking methods. PP (polypropylene) cross-linking modification can improve its mechanical properties, heat resistance, and morphological stability, and shorten the molding cycle. The main methods of polypropylene cross-linking modification include chemical cross-linking modification and radiation cross-linking modification, with the main difference being different cross-linking mechanisms and active sources