In situ compatibilization of PP/EPDM blends during ultrasound aided extrusion

Blends of isotactic polypropylene (iPP) and uncured ethylene-propylene diene rubber (EPDM) of various concentrations were treated by high power ultrasonic waves during extrusion. Die pressure and power consumption were measured. The effects of different gap sizes, blend ratios and number of ultrasonic horns were investigated. The rheological properties, morphology and mechanical properties of the blends with and without ultrasonic treatment were studied. In situ compatibilization of the blends was observed as evident by their more stable morphology after annealing, improved mechanical properties and IR spectra. The obtained results indicated that ultrasonic treatment induced the thermo-mechanical degradations and led to the possibility of enhanced molecular transport and chemical reactions at the interfaces. Processing conditions were established for enhanced in situ compatibilization of the PP/EPDM blends.     

烃链功能改性剂对三元乙丙橡胶/凹凸棒土复合材料性能的影响

采用机械共混法制备三元乙丙橡胶(EPDM)/凹凸棒土(AT)复合材料,考察了不同结构的烃链功能改性剂对复合材料硫化性能、力学性能和应力松弛行为及相结构的影响,探究3种烃链功能改性剂对凹凸棒土在复合材料中分散作用的机理。结果表明,改性剂锚固在AT表面并与EPDM有良好相容性,使AT在EPDM中有更好分散性。改性剂添加量为AT的1%时,对EPDM/AT复合材料的力学性能改善效果最明显,其中,以胺基为端基,相对分子质量为2000左右的改性剂使EPDM和AT两相的界面结合性最好,复合材料的拉伸强度提高了304.34%,综合性能提高最为显著。     

裂解C9预加氢催化剂研制

研制一种新型耐硫、抗胶质镍系加氢催化剂，在固定床液相加氢装置评价催化剂性能，考察催化剂制备方法、载体和助剂种类对裂解C₉馏分加氢性能的影响。结果表明，浸渍法制备的催化剂活性较高，添加稀土分子筛及助剂后的催化剂低温活性更好。在反应器入口温度（60～80） ℃、空速1.5 h^-1、反应压力3.0 MPa和氢油体积比500∶1条件下，对催化剂进行240 h稳定性实验，裂解C₉馏分的双烯值由5.3 g-I₂·（100g）^-1降至约0.60 g-I₂·（100g）^-1，溴值由57.2 g-Br₂·（100g）-^-1降至约25.5 g-Br₂·（100g）^-1，稳定性良好。     

马来酸酐法分析煤基液体产品二烯值的可行性研究

为研究马来酸酐法测定煤基液体产品中共轭二烯烃含量的可行性,考察了煤焦油、脱酚煤焦油、酚类物质和费托油中醇类物质对马来酸酐法分析煤基液体产品中二烯值的影响,结果表明,试验中低温煤焦油样品的二烯值为15.17 g/100 g,经过脱酚处理的煤焦油样品二烯值显著降低,为5.65g/100 g,而苯酚、甲酚、二苯酚等酚类物质对马来酸酐法测定结果没有明显影响,说明煤焦油中其他酸性组分对马来酸酐法测定的二烯值结果影响很大。费托油中的醇类物质可与马来酸酐发生反应,对马来酸酐法测定的结果影响较大。因此马来酸酐法不适用于费托油中共轭二烯烃含量的测定。     

原位合成甲基丙烯酸锌改性三元乙丙橡胶/聚丙烯热塑性弹性体

以过氧化二异丙苯(DCP)为交联剂,研究了ZnO与甲基丙烯酸原位合成的甲基丙烯酸锌(ZDMA)为助交联剂对动态硫化三元乙丙橡胶/聚丙烯热塑性弹性体(EPDM/PPTPV)性能的影响。结果表明,当交联剂DCP的用量为1份时,含有ZDMA的EPDM/PPTPV具有较佳的力学性能;当EPDM/PPTPV中填充5~20份ZDMA时,其力学性能较佳;随着ZDMA填充量的增加,PP的结晶度不断下降。     

部分硫化的PP／LDPE／EPDM共混体系的研究

讨论了部分硫化的PP/LDPE/EPDM共混体系的硫化体系、硫化温度、硫化时间以及碳黑、滑石粉对性能的影响。结果表明:过氧化二异丙苯(DCP)与硫磺的配合使用使共混物的拉伸强度和硬度得到提高,断裂伸长率和压缩永久变形降低;碳黑与滑石粉配合使用且配比为15/15时,共混物的性能相对较好。     

HNBR/EPDM共混硫化胶的性能

研究了HNBR／EPDM共混硫化胶的性能与EPDM质量分数的关系。结果表明，EPDM的加入对HNBR的硬度影响不大，但对HNBR胶料的粘度及硫化性能产生影响，当EPDM质量分数不大于15％时，在改善HNBR低温顺性能的同时，保持其较高的拉伸强度和优异的耐油性能。     

Mechanical property and morphology comparison between the two blends poly(propylene)/ethylene‐propylene‐diene monomer elastomer and poly(propylene)/maleic anhydride‐g‐ethylene‐propylene‐diene monomer

The comparison of the mechanical properties between poly(propylene)/ethylene‐propylene‐diene monomer elastomer (PP/EPDM) and poly(propylene)/maleic anhydride‐g‐ethylene‐propylene‐diene monomer [PP/MEPDM (MAH‐g‐EPDM)] showed that the latter blend has noticeably higher Izod impact strength but lower Young's modulus than the former one. Phase morphology of the two blends was examined by dynamic mechanical thermal analysis, indicating that the miscibility of PP/MEPDM was inferior to PP/EPDM. The poor miscibility of PP/MEPDM degrades the nucleation effectiveness of the elastomer on PP. The observations of the impact fracture mode of the two blends and the dispersion state of the elastomers, determined by scanning electron microscopy, showed that PP/EPDM fractured in a brittle mode, whereas PP/MEPDM in a ductile one, and that a finer dispersion of MEPDM was found in the blend PP/MEPDM. These observations indicate that the difference in the dispersion state of elastomer between PP/EPDM and PP/MEPDM results in different fracture modes, and thereby affects the toughness of the two blends. The finer dispersion of MEPDM in the blend of PP/MEPDM was attributed to the part cross‐linking of MEPDM resulting from the grafting reaction of EPDM with maleic anhydride (MAH) in the presence of dicumyl peroxide (DCP). © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2486–2491, 2002     

助交联剂对三元乙丙橡胶过氧化物硫化的影响

分别采用三烯丙基异氰脲酸酯(TAIC)、三羟甲基丙烷三甲基丙烯酸酯(TMPTMA)以及高乙烯基聚丁二烯(HVPBd)作为过氧化物硫化三元乙丙橡胶(EPDM)的助交联剂,研究其对EPDM胶料硫化特性及硫化胶力学性能的影响。结果表明,3种助交联剂的添加能明显促进硫化程度,硫化胶的硬度和定伸应力均明显提高,添加TAIC的EPDM混炼胶硫化程度最高,但添加TMPTMA使胶料的焦烧安全性变差,而添加HVPBd的EPDM胶料降解程度最低。通过一级动力学模型及自催化反应模型研究EPDM硫化动力学行为时发现,助交联剂类型影响胶料的硫化反应速率,其中TMPTMA能明显促进硫化反应速率,TAIC次之,而HVPBd几乎没有影响,但硫化反应表观活化能由于助交联剂的添加均出现降低,其中添加TAIC胶料的表观活化能最低。