共查询到19条相似文献,搜索用时 109 毫秒
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杯芳烃/聚丙烯共混体系耐热氧性能的研究 总被引:2,自引:0,他引:2
合成了对叔丁基杯[4]、杯[6]、杯[8]芳烃,并用热重法和烘箱老化评价了共混体系的耐热氧性能。结果表明,杯芳烃能明显提高聚丙烯的耐热氧性能,其耐热氧能力为:对叔丁基杯[6]芳烃>对叔丁基杯[4]<2,6-二叔丁基-4-甲基苯酚。 相似文献
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对叔丁基苯酚和甲醛在KOH催化下制备对叔丁基杯[6]芳烃。用荧光光谱法研究了对叔丁基杯[6]芳烃与黑索金(RDX)在溶液中的相互作用,结果表明对叔丁基杯[6]芳烃与RDX在溶液中存在较强的配合作用,RDX的激发峰发生明显红移,荧光强度增强,主客体间发生了包合作用。通过对叔丁基杯[6]芳烃-RDX配合物的发射光谱与紫外光谱分析,确定了在DMF溶液中对叔丁基杯[6]-RDX配合物的化学计量比为1∶1,稳定常数为325.70。 相似文献
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对叔丁基杯[6]芳烃是杯芳烃的一种基本原料,而杯芳烃由于其环腔大小可调,可进行多种化学修饰等特点,从而有模拟酶催化、传输、分离与富集等方面具有广阔的应用前景,目前大多数杯[6]芳烃的衍生物都是以从对叔丁基杯[6]芳烃出发经适当步骤进行合成的,因而能够以高产率得到对叔丁基杯[6]芳烃具有重要意义。经多年摸索与研究,Gutsche等人将对叔丁基杯芳烃其产率提高到80%以上,但实验方法不易掌握、不易重复,而且和得到的粗产品中往往含有一定量的对叔丁基杯[8]芳烃、对叔丁基杯[4]芳烃等副产品,因而在重结晶纯化以后导致对叔丁基杯[6]芳烃的产… 相似文献
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以对叔丁基苯酚、甲醛为主要原料合成杯芳烃母体对叔丁基杯[n]芳烃(n=4,6,8);以1,3-丙烷磺内酯、1,4-丁烷磺内酯为醚化试剂,经Williamson醚化反应,合成出6种杯芳烃基低聚表面活性剂。利用IR表征了中间体和最终产物的结构,确定了化合物的结构与所设计的分子结构相同。用染料法对所合成产物进行了定性鉴定,并用滴体积法测定了表面活性剂水溶液25℃时的表面张力。结果表明,随着杯芳烃空腔的逐渐增大,cmc值降低,γcmc值升高,Γcmc值下降,Am值升高。 相似文献
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Polyamide 1010/poly(propylene) (PA1010/PP) blends were investigated with and without the addition of poly(propylene)-graft-glycidyl methacrylate (PP-g-GMA). The effect of the compatibilizer on the thermal properties and crystallization behavior was determined by differential scanning calorimetry and wide-angle X-ray diffraction. From the results it is found that the crystallization of PA 1010 is significantly affected by the presence of PP-g-GMA. PP/PA 1010 (75/25) blends containing higher amounts of PP-g-GMA show concurrent crystallization at the crystallization temperature of PP. Isothermal crystallization kinetics also were performed in order to investigate the influence of the compatibilized process on the nucleation and growth mechanism. In the PP/PA 1010 (25/75) blends, concurrent crystallization behavior was not observed, even though the amount of PP-g-GMA was high. 相似文献
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纳米SiO_2对聚丙烯/环氧树脂共混物性能的影响 总被引:1,自引:1,他引:0
采用熔融共混法制备了聚丙烯(PP)/环氧树脂(EP)共混物,研究了纳米SiO2对共混物性能的影响。结果表明:与纯PP相比,PP/EP共混物的冲击强度、断裂伸长率及黏度降低,弯曲模量增大;在PP/EP共混物中加入纳米SiO2后,共混物弯曲模量和冲击强度明显提高;将硅烷偶联剂KH550改性的纳米SiO2(SiO2-KH550)添加到共混物中,在EP为17%、SiO2-KH550为7%时,共混物的弯曲模量比纯PP提高了64%;EP降低了PP的结晶温度。 相似文献
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Arnon Siegmann 《应用聚合物科学杂志》1982,27(3):1053-1065
The crystallization, from molten blends, of polypropylene (PP) and polybutene-1 (PB), two highly crystallizable, polymers, their interaction in the amorphous phase, and the resulting tensile mechanical properties were studied. The crystallization was followed by DSC, showing two separate PP and PB crystallization processes which are affected each by the presence of the other component. The crystallization temperature of PP is significantly affected only in PB rich blends whereas that of PB is affected in the whole composition range. The PP crystalline phase, acting as a nucleating agent, increases the PB crystallization temperature whereas the PP amorphous phase, acting as a high viscosity polymeric diluent, reduces the PB crystallization temperature. The first effect is dominant at low PP content, and the second one becomes increasingly effective with increasing PP content in the blend. The interaction between the two polymers in the amorphous phase was studied by applying dynamic mechanical analysis, in which a single glass transition was observed for the blends and its temperature was found to vary with the blends' composition. Tensile mechanical properties of blends were found to be more sensitive to thermal treatments, such as isothermal crystallization or annealing at elevated temperatures, than single component systems. Such thermal treatments enable better structured blends to be formed, resulting in mechanical properties with no abrupt changes in the whole composition range. 相似文献
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Crystallization of polypropylene (PP) in unvulcanized blends of PP with the butadiene–styrene block copolymer (SBS) was studied through differential scanning calorimetry (DSC) and X‐ray diffraction measurements in the composition range of 0–40 wt % SBS content. Analysis of the crystallization exotherms revealed variation in the crystallization behavior, crystallinity, and crystalline morphology of the PP component in the blends at various levels of SBS concentration. The crystallinity determined by X‐ray diffraction and DSC showed identical variations with the blend composition. The tensile and thermal properties of the blends were studied in the entire composition range. Correlations of the tensile properties with the crystallization parameters of the PP component in the blends are also presented. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 151–161, 1999 相似文献
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Polypropylene (PP)/metallocene‐catalyzed polyethylene elastomer (mPE) blends were prepared in a twin‐screw extruder. The melting behavior, crystallization behavior, and isothermal crystallization kinetics of the blends were studied with differential scanning calorimetry. The results showed that PP and mPE were partially miscible and that the addition of mPE shifted the melting peak of PP to a lower temperature but the crystallization temperature to a higher temperature, demonstrating a dilution effect of mPE on PP. The isothermal crystallization kinetics of the blends were described with the Avrami equation. The values of the Avrami exponent indicated that the nucleation mechanism of the blends was heterogeneous, the growth of spherulites was almost three‐dimensional, and the crystallization mechanism of PP was not affected much by mPE. At the same time, the Avrami exponents of the blends were higher than that of pure PP, and this showed that the addition of mPE helped PP to form more perfect spherulites. The crystallization rate of PP was increased by mPE because the dilution effect of mPE on PP increased the mobility of PP chains. The crystallization activation energy was estimated with the Arrhenius equation, and the nucleation constant was determined by the Hoffman–Lauritzen theory. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
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马来酸酐接枝物对PE/PA6共混物相容性的影响 总被引:2,自引:0,他引:2
采用熔融共混法制备了PP/PA6/POE-g-MAH和PP/PA6/PP-g-MAH共混物。通过扫描电子显微镜(SEM)、差示扫描量热(DSC)仪分析和力学性能测试研究了增容剂POE-g-MAH和PP-g-MAH对PP/PA6共混物相容性、形态结构和宏观力学性能的影响。结果表明,在PP/PA6共混体系中分别加入POE-g-MAH和PP-g-MAH不仅能显著改善两相界面的相容性,减小分散相的粒径,而且能使共混物的力学性能显著提高。当增容剂的用量为5份时,PP/PA6共混物有较好的综合力学性能。POE-g-MAH和PP-g-MAH增容PP/PA6共混体系非等温结晶行为的研究表明,POE-g-MAH和PP-g-MAH均能促进PA6对PP基体的异相成核作用。 相似文献
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Nonisothermal crystallization, melting behavior, and morphology of polypropylene (PP)/Easy processing polyethylene (EPPE) blends were studied by differential scanning alorimetry (DSC) and scanning electron microscope (SEM). The results showed that PP and EPPE are miscible, and there is no obvious phase separation in microphotographs of the blends. The modified Avrami analysis, Ozawa equation, and also Mo Z.S. method were used to analyze the nonisothermal crystallization kinetics of the blends. Values of Avrami exponent indicated the crystallization nucleation of the blends is homogeneous, the growth of spherulites is tridimensional, and crystallization mechanism of PP is not affected much by EPPE. The crystallization activation energy was estimated by Kissinger method. The result obtained from modified Avrami analysis, Mo Z.S. method, and Kissinger methods were well agreed. The addition of minor EPPE phase favored to decrease the overall crystallization rate of PP, showing some dilution effect of EPPE on PP. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献