Hecheng xiangjiao gongye (May 2023)
Modification method and reinforcing effect of waste tire pyrolytic carbon black on natural rubber
Abstract
A planetary ball mill was used to treat the pyrolytic carbon black (CBp) of waste tire by dry modification with 3 types of modified resins, PA, PF-203 and Polstal-PC as the modifiers, the changes of physico-chemical properties and structure of CBp before and after modification were explored, and the effects of modified CBp on curing characteristics, cross-linking density, mechanical properties and dynamic mechanical properties of natural rubber were investigated. The results showed that the particle size of CBp decreased with the extension of milling time. The mo-dified resin Polstal-PC had the most obvious grinding effect, and compared with unmodified CBp, the total specific surface area of CBp modified by Polstal-PC increased from 65.1 m2/g to 97.4 m2/g and the specific surface area of the outer surface increased from 63.0 m2/g to 71.6 m2/g. All of the 3 type of modifiers contributed to vulcanization of natural rubber, and CBp modified by Polstal-PC could significantly improve tensile strength, modulus at 300% and cross-linking density of natural rubber vulcanizate, and the addition of CBp modified by tackifying resin PA could cause the decrease of modulus and cross-linking density. CBp modified by Polstal-PC had the best enhancement effect on natural rubber, and natural rubber vulcanizate showed the best comprehensive performance when the addition amount of CBp modified by Polstal-PC was 2 phr (mass, similarly hereinafter), and as far as CBp modified by Polstal-PC was concerned, the improvement of rolling resistance of natural rubber vulcanizate was better than the loss of wet skid resistance. However, storage modulus of natural rubber vulcanizate increased significantly when the addition amount of CBp modified by Polstal-PC was more than 3 phr.
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