Preparation And Application Of Macromolecular Coupling Agent For Rubber Inorganic Filler

The rubber and plastic materials are affected by the performance of their own structure,the inorganic filler often cannot meet the use requirements of rubber and plastic materials due to the different polarity.Therefore,the surface modification of the inorganic filler is the main aspect of improving the performance of the matrix material.Since the interaction force between the inorganic filler and the organic matrix is small after the surface modification of the small molecule coupling agent,the performance of the composite material can’t be improved and can’t meet the requirements of use.Therefore,the modification of the filler by the macromolecular coupling agent is gradually developed.Not only can macromolecular coupling agents with different structures and molecular weights be designed according to requirements,but also a strong chemical bond is formed between the macromolecular chain and the polymer matrix,which can strengthen the interface structure between the polymer matrix and the filler.In this paper,macromolecular coupling agents with different molecular weights and structures were independently designed and prepared.Spray method was used to study the performance improvement of SBR filled with kaolin after surface modification.By improving the interface bonding between materials with different polarities,the macromolecular coupling agent can control and optimize the interface structure between inorganic fillers and rubber-plastic materials,and improve the strength,modulus and performance of composite materials.The specific research contents are as follows:1、First,the compound of P[Isoprene-co-3-(Methacrylate oxygen)propyltrimethoxysilane)](PIPMSI)was synthesized by activity controlled reversible addition-fragmentation chain transfer(RAFT).Secondly,the PIPMSI solution was sprayed on the surface of the kaolin and dried to obtain the modified kaolin(MSi-Kaol).Adding MSi-Kaol and pure kaolin into SBR to obtain SBR/MSi-Kaol and SBR/Kaol.It was found that the storage modulus(G’)of SBR/Kaol under low strain condition is much lower than that of SBR/MSi-Kaol compound,and the vulcanization rate of SBR/MSi-Kaol compound is much lower than that of SBR/Kaol.The dispersion and distribution of kaolin in SBR/MSi-Kaol is significantly better than that of SBR/Kaol compound.MSi-Kaol significantly improved the tear and tensile properties of SBR matrix after filling.2、Firstly,Poly(Isoprene-co-Maleic anhydride)random copolymer(PIPMA)was synthesized by RAFT polymerization.Secondly,PIPMA was dissolved and sprayed on the surface of kaolin to obtain modified kaolin(PM-Kaol).It was found that the storage modulus(G’)of SBR/Kaol compound under low strain condition is much lower than that of SBR/PM-Kaol,and the vulcanization rate of SBR/PM-Kaol compound is much lower than that of SBR/Kaol compound.The SEM image shows that the dispersion effect of kaolin in SBR/PM-Kaol vulcanizate is better than that of SBR/Kaol vulcanizate.The experimental data showed that the macromolecular coupling agent PIPMA was successfully polymerized by raft,and the interaction,stretching,fracture and tearing of the filler-matrix were significantly improved after PM-Kaol filling into the SBR matrix.3、Firstly,Poly[methyl methacrylate-co-3-(methacrylate oxygen)propyltrimethoxysilane)](PTMA)random copolymer with molecular weight of 20 K and 10 K was synthesized by RAFT polymerization.Secondly,the random block copolymers poly[methyl methacrylate-co-3-(Methacryloyloxy)propyltrimethoxysilane-b-polyisoprene](PTMAIP)with different molecular weights were synthesized by RAFT polymerization of polyisoprene(PIP)with molecular weights of 40 K and20K and PTMA with molecular weights of 20 K and 10 K,respectively.Finally,the macromolecular silane coupling agent PTMAIP with different molecular weight blocks is dissolved and sprayed into kaolin to form modified kaolin,namely PP-Kaol(40k-20k)and PP-Kaol(20k-10k).SBR/PP-Kaol and SBR/Kaol were obtained by adding PP-Kaol and pure Kaol modified by macromolecular coupling agents with different molecular weights into SBR at the same time.The storage modulus(G’)of SBR/Kaol compound is much lower than that of SBR/PP-Kaol;The vulcanization rate of SBR/PP-Kaol compound was slightly lower than that of SBR/Kaol compound;The dispersion effect of kaolin in SBR/PP-Kaol vulcanizate is better than that in SBR/Kaol vulcanizate.Compared with SBR/Kaol,the filler dispersion,filler rubber interaction and mechanical properties of SBR/PP-Kaol were significantly improved.