受阻酚功能化二氧化硅的制备及在天然橡胶中的应用

Preparation of Hindered Phenol Functionalized Silica and Its Application in Natural Rubber

采用γ-巯丙基三甲氧基硅烷(KH590)对二氧化硅进行表面改性引入巯基,然后利用巯基与2-叔丁基-6-(3-叔丁基-5-甲基-2-羟)苯(GM)上的C=C双键进行加成反应,制得受阻酚功能化二氧化硅(GM-g-Si O2)。通过红外光谱、热重法和亲油性实验对其进行了表征,采用扫描电镜对其在天然橡胶硫化胶中的分散状态进行了观察,并研究了其对硫化胶抗热氧老化性能和耐抽提性能的影响。结果表明,GM在二氧化硅表面的接枝率为7.3%。与未改性二氧化硅相比,GM-gSi O2的亲油性以及在硫化胶中的分散性得到提高,并能改善天然橡胶的硫化特性。添加GM-g-Si O2的硫化胶具有优良的抗热氧老化性能和耐抽提性能。

Hindered phenol functionalized silica was prepared through the reaction between C = C double bonds of 2-tert-butyl-6-（3-tert-butyl-2-hydroxy-5-methylbenzyl）-4-methyphenyl acrylate（ GM） and mercapto group of γ-mercaptopropyl trimethoxysilane（ KH590） modified silica. Hindered phenol functionalized silica was characterized by FT-IR,thermogravimetry（ TG） and lipophilicity test,and its dispersion in natural rubber（ NR） vulcanizates was observed by SEM. The thermal-oxidative aging resistance and extraction resistance of NR vulcanizates with hindered phenol functionalized silica were also studied. The results show that the grafting rate of GM on silica is 7. 3%. Contrast to neat silica,the lipophilicity of the functionalized silica and its dispersion in NR vulcanizates increase,and the vulacanizing properties of NR could be improved obviously. The NR vulcanizates with hindered phenol functionalized silica exhibit excellent thermal-oxidative aging resistance and extraction resistance.