不同动态硫化设备NBR/PA12热塑性硫化胶的制备和性能研究

Preparation and properties of nitrile rubber/nylon 12 thermoplastic vulcanizate by different dynamic vulcanization equipment

采用开炼机、Haake密炼机和双螺杆挤出机3种动态硫化设备制备了丁腈橡胶(NBR)/尼龙12(PA12)热塑性硫化胶(TPV),研究了在相同配方下3种不同设备对NBR/PA12TPV微观相态结构、物理性能、热力学性质的影响,并考察了开炼机设备制备的TPV的重复加工性能。结果表明,3种设备制备的TPV为两相"海岛"结构,NBR为分散相,PA12为连续相;开炼机制备的TPV的NBR平均粒径最小且分布均匀,物理性能最佳;双螺杆挤出机制备的TPV的NBR硫化和剪切破碎不充分,平均粒径最大且分布宽,熔融焓最大;开炼机制备的TPV具有优异的重复加工性能,返炼次数增加,TPV的硬度逐渐增加,拉伸强度、撕裂强度先增加而后减小,耐油性能提高。

The nitrile rubber（NBR） /nylon12（PA12） thermoplastic vulcanizates（TPV） were prepared by two-mill,Haake internal mixer and twin screw extruder.The morphological structure,physical property and thermodynamic behavior were investigated under the same formulation,and the repetitive processing property of NBR/PA12 TPV prepared by two-mill was also discussed.The results showed that the TPV behaved as two-phase sea-island structure with PA 12 as continuous phase and NBR as dispersed phase.The TPV prepared by two-mill had the minimum particle size,the best dispersion of NBR vulcanizate and the most excellent physical property.While the TPV prepared by twin screw extruder had the maximal particle size,and the distribution of particle size was broad due to inadequate curing and mixing,but it had the maximal melting enthalpy.The TPV prepared by two-mill exhibited excellent repetitive processing property,with increasing the repetitive processing times,the Shore A hardness and oil resistance increased,and the tensile strength and tear strength initially increased and then decreased.