天然橡胶-氢化丁腈橡胶的共硫化及性能研究

天然橡胶(NR)和氢化丁腈橡胶(HNBR)因不饱和度和极性的差异,存在硫化速度不匹配、填料分散等问题,难以实现两胶的并用。本文通过先制备不同硫黄/促进剂比例的NR和HNBR母炼胶,再将母炼胶并用制备NR/HNBR复合材料,解决了NR和HNBR共硫化的问题。研究了NR/HNBR的相态结构和填料在NR和HNBR两相的分散状态,结合相态结构和填料分散分析了NR/HNBR并用比对复合材料硫化特性、动静态力学性能、耐磨性和压缩温升的影响。结果表明:并用HNBR的复合材料混炼胶的门尼黏度增大,焦烧时间和正硫化时间缩短;随着HNBR含量增加,HNBR相的尺寸增大,硫化胶的硬度及100%和300%定伸应力增加,拉伸强度、撕裂强度、断裂伸长率和拉断永久变形减小,耐磨性和抗湿滑性提高,压缩疲劳温升增大。     

ESBR/PU复合混炼胶共硫化研究

探讨了硫化体系和活性剂对乳聚丁苯橡胶(ESBR)/聚氨酯(PU)复合混炼胶以及聚氨酯混炼胶性能的影响。结果表明:采用硫磺硫化体系硫化的ESBR/PU力学性能较过氧化物硫化的优,但ESBR和PU二者的硫化动力学差异较大,难以达到良好的共硫化效果;添加进口活性剂NH-1能显著加快PU硫化速率,而自制复配活性剂FA的活化效率与NH-1相当;采用传统硫磺促进/活性体系,添加复配活性剂FA,能显著提升ESBR/PU共硫化效果和复合硫化胶的综合性能。     

天然橡胶/三元乙丙橡胶共混相态结构对性能的影响

研究天然橡胶(NR)/三元乙丙橡胶(EPDM)体系并用比与粘度比的变化对其物理性能、耐老化性能及相态结构的影响。结果表明:分别调整NR和EPDM的硫化特性并使之保持一致时,可以改善NR/EPDM并用胶的共硫化性能;NR/EPDM体系粘度比不变,NR含量越大,呈连续相态,并用胶的耐老化性能越差;NR/EPDM体系并用比不变,EPDM粘度越低,容易成为连续相态,并用胶的耐老化性能明显提升。     

共混橡胶的共硫化研究

探讨了多种共混橡胶的共硫化体系及其对共混橡胶性能的影响。其中采用共硫化剂硫化CO/ECO、CSM/NBR、IIR/EPDM、IIR/CIIR共混胶,采用复合硫化剂硫化PUR/CR、ACM/ECO、ACM/NBR、CR/CIIR、CR/SBR共混胶,研究了硫化体系品种和用量对几种共混胶的硫化特性和力学性能的影响,为共混橡胶的硫化提供研究方案和理论指导。     

共混比对氟橡胶氟硅橡胶共混胶性能的影响

氟橡胶是一种主链及侧链上的碳上连接有氟原子的一种合成高分子弹性体。氟橡胶具有优异的耐油、耐高温、耐酸碱、耐高真空等性能,同时由于氟原子的存在,使分子链极性增加、耐低温性能变差,这极大限制了氟橡胶的应用范围。笔者拟通过将其与氟硅橡胶共混来改进氟橡胶低温性能。我们选用苏威公司生产型号为PL958的氟橡胶,该规格氟橡胶具有自由基硫化反应位点,可以与氟硅橡胶实现共硫化。结果表明,氟橡胶/氟硅橡胶共混比为8:2时,共混胶具有优异的综合性能。     

Curing characteristics and kinetics of EPDM and EOC compounds in co-vulcanization as blend

Possibility of co-vulcanization of ethylene octene copolymer (EOC) and ethylene propylene diene terpolymer (EPDM) molecules was studied by assessing the curing characteristic and crosslinking kinetics of EOC and EPDM compounds. Regarding curing, the curing characteristics, cure rate index, and the torque difference (M_H − M_L) of the EPDM compound are quite similar to those of the EOC compounds at the curing temperature of 180 °C, especially when the EOC octene comonomer content is 5.9 or 9.7 mol %. The kinetic parameters E _a and k were analyzed. The study showed that EOC with 9.7 mol % octene comonomer content is very suitable for blending with EPDM, as it has crosslinking kinetics similar to the EPDM. This observation confirms the possibility of chemical co-crosslinking at EPDM–EOC interfaces, especially at the curing temperature of 180 °C. Differential scanning calorimetry and dynamic mechanical analysis were also used to assess interfacial crosslinking. The lowest activation energy of vulcanization is found for the EPDM/EOC blend with 9.7 mol % octene comonomer contents. Furthermore, chemical co-crosslinking in combination with chain flexibility in the EPDM/EOC blend with 9.7 mol % octene comonomer contents give lower tan δ at room temperature than for the blends with octene comonomer contents of 5.9 and 16.9 mol %. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47613.     

NR／EPDM并用胶共硫化的研究

采用了一种新的工艺方法－热处理－动态硫化法，有效地改善了ＮＲ／ＥＰＤＭ并用胶的共硫化性和力学性能。在硫化体系不变的情况下，可用硫化曲线定笥比较并用胶的共硫化程度。通过分析比较认为，粘弹谱仪法是测定并用硫化胶两相交联程度的简便可靠方法。