天然橡胶与其环氧化物并用胶基复合材料的黏弹阻尼性能

为改善天然橡胶（NR）的阻尼性能，在密炼机中以质量比20：80混合不同环氧度环氧化天然橡胶（ENR）与天然橡胶制备ENR-NR并用橡胶基体，在橡胶基体的混炼与开炼过程加入其他填充组分（硫磺、促进剂2，2'-二硫代二苯并噻唑（DM）、促进剂N-环己基-2-苯并噻唑次磺酰胺（CZ）、ZnO、硬脂酸、炭黑）得到了宽温域阻尼ENR-NR基复合材料。采用橡胶加工分析仪和动态力学热分析仪，研究了ENR-NR混炼胶和硫化胶的动态力学和阻尼性能。结果表明：NR环氧化增强了分子链局部刚性，改善了胶体与填料的黏结性，但ENR吸附较多炭黑后不易均匀分散于连续相NR中。因此，ENR-NR并用混炼胶的黏度和储能模量随ENR环氧度增大而增加；在NR中加入ENR可改善硫化胶的弹性和阻尼性能。ENR-NR并用胶的有效阻尼温度范围拓宽到较高温度，环氧度为25的ENR与NR并用后，有效阻尼温度范围为-57~1℃，明显宽于NR的-57~-20℃，但高环氧度并用胶则出现阻尼失效区。加入少量ENR对NR的硬度、模量和断裂伸长率影响不大。

Viscoelastic damping properties of natural rubber-epoxidized natural rubber composites

In order to improve the damping performance of natural rubber (NR), it was blended in mass ratio of 20:80 with epoxidized natural rubber (ENR) of different epoxidation degrees in a mixer to obtain blend rubber matrix of ENR-NR. The ENR-NR matrix was further filled in mixing and smelting process with other components (sulfur, accelerator 2,2'-dibenzothiazole disulfde(DM), promoter N-cyclohexylbenzothiazde-2-sulphenamide(CZ), ZnO, stearic acid, carbon black) to prepare a wide temperature-range damping ENR-NR matrix composites. The dynamic mechanical properties and the damping characteristics of the plasticized ENR-NR mixtures and their vulcanized rubbers were tested by rubber processing analyzer (RPA) and DMA. The results show that epoxidation of NR enhances the rigidity local molecular chain and improves the adhesion between the matrix and the fillers while ENR adsorbing more carbon black is inhomogeneously dispersed in the continuous phase NR. ENR and its blend rubber with NR exhibit higher viscosity and storage modulus for ENR with higher epoxied degree. The combination of ENR into NR can obtain materials with better elastic and damping performances for vulcanizates when damping range is widened to higher temperature for ENR-NR compound rubber. The effective range is -57-1℃ for ENR-NR with epoxidation degree 25 in comparison with -57--20℃ for NR although there is ineffective damping zone for composite rubber when natural rubber being epoxidized to higher degree. However, the addition of a small amount of ENR has little effect on the hardness, modulus and elongation at break of NR matrix composite.