(1) Monoalkoxy type: This is the most widely used titanate coupling agent at present. It is especially suitable for filler systems without free water, such as calcium carbonate and alumina hydrate in full exercise. Those containing chemical or physical bonding water are beneficial for coupling. The typical representative of this kind of coupling agent is isopropyl triisostearoyl titanate (TTS).

(2) Monoalkoxypyrophosphate type: This kind of coupling agent is insensitive to water and can be used for inorganic fillers with high moisture content, such as clay, talc powder, etc. Because they can be combined with the filler surface by alkoxy breaking and pyrophosphate hydrolysis, as well as the phosphate ester group formed by pyrophosphate hydrolysis. Its representative variety is isopropyl tri (dioctyl pyrophosphate) titanate (TTOPP-38 or KR-38S).

(3) Chelating type: This kind of coupling agent has good hydrolysis resistance. Titanate coupling agent can therefore be used in high humidity conditions, suitable for wet silica, talc powder, clay, silica couples, carbon black and water treatment glass fibers. Its representative varieties are oxoacetyloxy and dioxyethylene.

(4) Ligand type: This kind of titanate coupling agent has the similar function with monoalkyl type, and its performance is relatively stable. It will not transesterify with resin or other auxiliaries. It is suitable for epoxy resin, PVC, polyester, polyurethane and other filling systems. Its representative variety is tetra-isopropyl (lauryl phosphite) titanate (KR-36S).