共查询到19条相似文献,搜索用时 234 毫秒
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对比分析了动态热塑性硫化胶(TPV)的加工设备,着重介绍了附加振动力场的三螺杆反应挤出机的结构特点以及利用该机进行三元乙丙橡胶/聚丙烯(EPDM/PP)的动态全硫化,对制品的物理力学性能和微观结构分别进行了测试分析和电镜扫描。结果表明,振动力场作用下EPDM/PP共混体系反应挤出动态硫化加工可有效地实现动态硫化反应、硫化橡胶的粉碎和分散以及相态反转,振动力场的作用明显提高了TPV性能。 相似文献
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低硬度EPDM—PP热塑性动态硫化胶II.制备工艺条件对微观相对态结构的影响 总被引:1,自引:0,他引:1
通过正交试验设计,研究了低硬度EPDM/PP共混型热塑性动态硫化胶的反应动态硫化制备工艺,初步探讨了机筒温度,喂料螺杆驱动电压及主机螺杆转速等主要工艺因素对挤出物微观相态结构的影响。 相似文献
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采用动态硫化的方法,在双螺杆挤出机中制备了聚丙烯(PP)/三元乙丙橡胶(EPDM)热塑性弹性体,研究了挤出反应温度与螺杆转速提供的剪切应力对动态硫化PP/EPDM热塑性弹性体性能的影响。结果表明,适当提高挤出反应温度或螺杆转速可提高PP/EPDM热塑性弹性体的拉伸强度、拉断伸长率和凝胶含量,当挤出反应温度为200℃、螺杆转速为600 r/min时,热塑性弹性体的综合拉伸性能最好,拉伸强度为19.87 MPa,拉断伸长率为527.3%,凝胶含量为54.69%。高螺杆转速提供的高剪切应力可在一定程度上提高PP/EPDM热塑性弹性体的熔融温度。 相似文献
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采用双螺杆挤出机通过动态硫化法制备了丁腈橡胶/尼龙12热塑性弹性体,考察了双螺杆挤出机的螺杆转速和机筒温度对所制备热塑性弹性体力学性能和微观形态的影响。结果表明,用双螺杆挤出机动态硫化制备的丁腈橡胶/尼龙12热塑性弹性体呈两相"海岛结构",即丁腈橡胶为分散相、尼龙12为连续相。随着挤出机螺杆转速的提高,弹性体的硬度、拉伸强度和扯断伸长率先增大后减小,撕裂强度和压缩永久变形逐渐降低;螺杆转速对弹性体耐油性能的影响不大;当螺杆转速增至400 r/min时,丁腈橡胶的粒径较小且分布均匀。随着双螺杆挤出机温度的升高,弹性体的硬度和拉伸强度逐渐增大,扯断伸长率、撕裂强度和压缩永久变形均先增大而后减小,耐油性能变差;温度升高使得丁腈橡胶难于在剪切作用下破碎,颗粒变大且分布不均。 相似文献
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《中国塑料》2017,(9)
以1,1-二叔丁基过氧基-3,3,5-三甲基环己烷(Luperox231)/N,N’-间苯撑双马来酰亚胺(HVA-2)为硫化体系,采用反应挤出动态硫化法制备了乙烯-乙酸乙烯酯共聚物(EVA)/聚甲醛(POM)动态硫化热塑性弹性体。结果表明,EVA/POM动态硫化热塑性弹性体的综合力学性能明显改善,拉伸强度可达到12 MPa左右,但断裂伸长率较低;螺杆转速和挤出机加工温度对EVA/POM动态硫化热塑性弹性体的力学性能有影响,为制备性能良好的EVA/POM动态硫化热塑性弹性体,螺杆转速设定为250r/min,挤出机加工温度为145~175℃;Luperox231用量的增加使动态硫化热塑性弹性体的拉伸强度和断裂伸长率、永久变形以及肖D硬度均下降,而HVA-2用量的增加使动态硫化热塑性弹性体的拉伸强度和永久变形呈先降低后升高的趋势。 相似文献
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概述了动态硫化热塑性弹性体的制备原理和方法,介绍了电磁动态反应挤出和固相聚合一双螺杆挤出制备新方法,总结了共混体系的配方和工艺条件对产物结构和性能的影响,分析了EPDM/PP、IR/PP、NBR/PP、ACM/PP等几种典型的动态硫化共混物的性能特点和应用领域。 相似文献
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硅灰石填充 PP 经三螺杆动态塑化混炼加工后,将粒料制成试样并进行力学性能测试和扫描电镜断面分析。实验研究了不同振动参数对 PP/硅灰石力学性能和断面微观结构的影响。结果表明,与稳态相比,动态(引入振动)加工条件下试样的冲击强度、拉伸强度、断裂伸长率和弯曲强度均有显著提高,最大分别提高了10.7%、10.2%、51.3%和18.6%;对在振动频率 f=10 Hz、振幅 A=105 μm动态塑化混炼加工条件下试样的扫描电镜断面分析表明,PP/硅灰石材料中硅灰石的粒径变小并趋于一致,分散分布均一,与 PP 结合界面得到加强。 相似文献
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Shikui Jia Jinping Qu Shufeng Zhai Zan Huang Chengran Wu Rongyuan Chen Yanhong Feng 《Polymer Composites》2014,35(5):884-891
Low‐density polyethylene (LDPE)/nanoprecipitated calcium carbonate (NPCC) nanocomposites were prepared with a self‐made vane extruder (VE) that generates global dynamic elongational flow and with a single‐screw extruder (SSE) that generates low shear flow. The mechanical properties, dispersed phase morphology, and thermal behavior of the nanocomposites were investigated to compare the different processing techniques. Scanning electron micrograph and transmission electron micrograph show that the elongational flow in the VE improves the dispersion of NPCC (5 wt%) particles in the LDPE matrix. The dimensional distribution of NPCC particles in the VE is significantly lower than that of the SSE. Differential scanning calorimetric curves indicate that dynamic elongational flow can enhance the crystallization ability of the LDPE/NPCC nanocomposites. The mechanical properties of the VE‐extruded samples are superior to those of the SSE‐extruded samples. When compared with that of SSE, morphology of tensile fracture surfaces suggests that the uniform and fine dispersion of NPCC particles in the LDPE matrix can successfully improve modulus and toughness of the LDPE/NPCC nanocomposites based on the novel VE. POLYM. COMPOS., 35:884–891, 2014. © 2013 Society of Plastics Engineers 相似文献
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利用塑料电磁塑化挤出机挤出聚烯烃片材,系统研究了挤出机螺杆轴向振动对聚乙烯挤出制品结构与性能的影响。采用DSC对挤出试样的结晶结构及形态进行分析。结果表明,振动塑化挤出使聚合物挤出试样结晶度提高,结晶完善,晶片之间的连接分子数量增加,因而制品的力学性能有所提高,特别在横向上表现明显。在适当的振动条件下,高密度聚乙烯(HDPE)试样的横向拉伸强度和冲击强度分别从22.68MPa和12.7kJ/m^2提高到了25.55MPa和23.5kJ/m^2;而聚丙烯(PP)试样横向拉伸强度和冲击强度则分别提高了20%和64%。 相似文献
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The objective of this study is to investigate the effect of reactive processing of commingled bottle waste polymer in an extruder. A variety of peroxides and monomers were tested to assess their influence on the final mechanical properties of the product. The reactive extruded polymer blends were prepared in two types of extruders: a co‐rotating twin‐screw extruder and a Buss co‐Kneader single‐screw extruder. Blends were analyzed for mechanical and thermal properties. The effectiveness of the different monomers and peroxides was evaluated in terms of improvement in impact properties. It has been found that the toughness of the polymer blend is improved by reactive processing. Depending on the amount and type of reactants, the impact strength can be improved by 220%, with a slight reduction in the modulus compared to an unmodified physical blend. The most suitable monomers were n‐butylmethacrylate (BMA), t‐butylamino ethylmethacrylate (TBAEMA) and a combination of styrene/maleic anhydride (ST/MAH). The peroxide should have a short half‐lifetime compared to the average residence time in the extruder. The most effective monomers have a high initial reactivity and low rate of evaporation at the processing conditions used. Changes in processing conditions in the extruder influence the reaction conditions and therefore the final properties of the blend. Results were interpreted in terms of residence time, melting profile and peroxide concentration. 相似文献
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采用电磁动态塑化挤出机挤出聚丙烯(PP)管材,通过爆破压力测试、拉伸性能测试、差示扫描量热(DSC)分析和X射线衍射(XRD)分析研究了振动频率和振幅对PP管材结构与力学性能的影响。力学性能测试结果表明,振动挤出PP管材的周向强度有了显著提高,实现了管材的双向自增强。与稳态挤出的PP管材相比,振动挤出PP管材的爆破压力最大提高了27.03%,轴向拉伸屈服强度最大提高了7.3%。DSC分析和XRD分析表明,振动挤出的PP管材结晶度提高,熔点升高,结晶完善,晶粒变小,有利于管材力学性能的提高。 相似文献
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A high‐density polyethylene (HDPE) masterbatch containing 20.2 wt% multiwalled carbon nanotubes (MWNTs) was melt diluted with neat HDPE using two different methods: a twin screw microcompounder and a single‐screw extruder. The electrical properties of these composites were assessed using bulk electrical conductivity measurements, their mechanical properties were evaluated using tensile tests and dynamic mechanical analysis (DMA), and percent crystallinity was determined by wide angle x‐ray diffraction (WAXD) and differential scanning calorimetry (DSC). A percolation threshold (pc) of 4.5 wt% MWNTs was found in compression‐molded samples. Extruded samples were prepared with nanotube concentrations below and above the compression‐molded percolation threshold (2 and 7 wt% MWNTs) and passed through the extruder twice before entering a low‐shear melt annealing zone. Different melt annealing times were used and their effects on the electrical and mechanical properties of the resulting quench‐cooled composites were evaluated. Results showed that extruded composites were nonconductive, indicating that a conductive nanotube network did not form on the time scale of these experiments. Annealing time also did not affect significantly the mechanical properties of the resulting solid composites. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers 相似文献
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研究了噁唑啉官能化聚苯乙烯(RPS)与聚碳酸酯(PC)的共混反应,对反应性共混物及相应的非反应性共混物作了应力-应变试验及动态力学分析(DMA),并测定其接枝率及密度,发现反应性挤出共混提高了PS/PC共混物的力学性能。 相似文献