利用二乙醇胺和丙烯酸甲酯合成的N,N-二羟乙基-3-胺基丙酸甲酯作为AB2型单体,以纳米SiO_2为核,通过其表面羟基与单体的反应,制得SiO_2接枝超支化聚酯的纳米粒子(SiO_2-HBP);再利用超支化端羟基与α-己内酯进行开环反应,合成了含柔性长链的二氧化硅-长链超支化聚酯杂化物(SiO_2-HBP-L);然后将杂化物与丁苯橡胶共混,制备了SiO_2-HBP-L/SBR纳米复合材料.FTIR、XPS和TGA测试证实改性后纳米SiO_2表面接枝了含长链超支化聚酯.SEM测试结果表明,相对于未改性的纳米SiO_2,SiO_2-HBP-L在乙醇和橡胶基体中分散性较好,且改性后纳米SiO_2与复合材料的相容性明显提高.硫化性能测试表明,SiO_2-HBP-L能大大缩短胶料的正硫化时间,增大总交联密度;同时SiO_2-HBP-L/SBR纳米复合材料的力学性能和耐磨性能有较大的提高,很好地实现了补强.
N,N-Di-hydroxyethyl amine-3-propionic acid methyl ester was prepared in a nitrogen atmosphere.And SiO_2-HBP-L was in situ synthesized by grafting from with the monomers and α-caprolactone. The structure and morphology were characterized by FTIR,XPS and TG analysis. The results show that the hyperbranched polyester is successfully grafted at the surface of nano-SiO_2. Compared with the nano-SiO_2,the SEM shows that the dispersion and compatibility of SiO_2-HBP-L in the ethanol and rubber matrix is better. Then SiO_2-HBP-L/SBR composites were prepared by using the direct mixing method. Vulcanization performance tests show that the curing time( T90) of the composites are much shorter and the composites' total crosslinking density is increased with respect to SiO_2/SBR composites. When the composites with 30 phr SiO_2-HBP-L,the T90 was reduced to 3. 30 min. What is more,SiO_2-HBP-L/SBR composites have a great improvement of mechanical properties and wear resistance. It shows that the tensile strength,elongation at break,tear strength and wear resistance of the composites are increasing with the increase of contents of SiO_2-HBP-L. The tensile strength,elongation at break of the composites with 30 phr SiO_2-HBP-L were 14. 8 MPa and 22. 2 k N/m2,and its wear resistance decreased to 289. 4 mm3. Nano-SiO_2 modified with long-subchain hyperbranched polyester( SiO_2-HBP-L) was used in the preparation of SiO_2-HBP-L/SBR composites. The results show that the performance of SiO_2-HBP-L is better than that of nano-SiO_2 in the reinforcement of SBR.