共查询到19条相似文献,搜索用时 109 毫秒
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以聚丙烯为中心的改性技术 总被引:4,自引:0,他引:4
以聚丙烯为中心的改性技术张增民(清华大学化工系高分子研究所100084)0前言聚丙烯(PP)作为一种通用塑料,广泛应用于工业生产的各个领域,其产量仅次于PE和PVC,我国1995年PP的产量为112万吨,进口量为110万吨。PP所以能获得广泛的应用,... 相似文献
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聚丙烯改性技术及制品应用 总被引:5,自引:0,他引:5
介绍了我国聚丙烯质轻、耐腐蚀、易加工、力学均衡性好、价廉,但低温脆性大和成型收缩率大的特点、世界用量等发展现状及改性技术,列举一些改性技术实例,说明在复合材料中聚丙烯既可以作为增强材料也可以作为基体等情况。 相似文献
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介绍了我国聚丙烯质轻、耐腐蚀、易加工、力学均衡性好、价廉,但低温脆性大和成型收缩率大的特点及其发展现状和改性技术,列举一些改性技术实例,说明经过改性后显著提高其性能,大大拓宽其应用范围。 相似文献
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超临界水降解聚丙烯的工艺研究 总被引:1,自引:0,他引:1
采用间歇式管式反应器进行了超临界水降解聚丙烯实验,研究了影响聚丙烯降解的因素。实验结果表明,在温度400-450℃、压力23-35MPa及反应时间60-120min的条件下,超临界水能有效地降解聚丙烯。反应温度和反应时间是影响聚丙烯降解的主要因素,温度越高、时间越长,聚丙烯降解越彻底;聚丙烯颗粒度越小降解速率越快,粉末原料在温度400℃、反应时间60min时,以油相产物为主;在温度450℃、反应时间120min时,有利于得到气相产物。 相似文献
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高熔体强度聚丙烯(HMSPP)是聚丙烯的一种重要改性产品,具有广泛的用途。本文综述了高熔体强度聚丙烯的性能特点、用途、制备方法,以及国内外研究和开发情况。 相似文献
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针对无卤膨胀型阻燃剂与聚丙烯间存在相容性差的问题,综述了几种改善相容性的方法:对阻燃剂与聚丙烯进行表面改性,加入偶联剂、相容剂,采用微胶囊化技术;引入新型炭源;通过合成三组分一体化的单分子阻燃剂改善聚丙烯与阻燃剂的相容性。 相似文献
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胡廷芳 《化学工业与工程技术》2013,34(4):21-26
介绍了世界聚丙烯工艺技术和聚丙烯工业的主要专利特点,简述了气相法和本体法工艺以及国产聚丙烯催化剂在气相法聚丙烯工艺上的应用情况,并介绍了这些工艺在国内大型新建聚丙烯装置上的应用。 相似文献
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分析硝酸铵与硝基复合肥生产相关的基本特性,介绍利用改性硝酸铵氨酸法生产硝基复合肥的工艺流程及生产工艺控制注意事项。通过对配料、造粒、干燥、筛分、冷却、包膜工序指标的严格控制,硝基复合肥成球率可达到90%以上,存放3个月不结块,生产安全平稳运行。 相似文献
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Two polypropylene cast films of different crystalline structures (one with coexisting small rows of lamellae and spherulites and the other with only a spherulitic structure) were prepared by extrusion. The produced cast films were uniaxially hot drawn at T = 120 °C using a machine direction orientation (MDO) unit and the changes in structure and morphology were examined and related to barrier as well as tear and puncture properties. Structural changes in terms of the degree of crystallinity and crystal size distribution, orientation of the amorphous and crystalline phases, and the deformation behavior at the crystal lattice and lamellae scales were investigated using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), wide angle X-ray diffraction (WAXD), and small angle X-ray scattering (SAXS), respectively. A significant effect of the original crystal morphology on the alignment of the amorphous and crystalline phases was observed from FTIR and WAXD. The results also revealed that the deformation behavior of the crystal structure was dependent on the draw ratio (DR). Our findings showed that by increasing DR the crystal lamellae first broke up and oriented along the drawing direction and then, at large DR, they were deformed and created a fibrillar structure. Morphological pictograms illustrating the effects of original morphology and draw ratio on the stretched film microstructure are proposed. The tear resistance along the machine direction (MD) decreased significantly with increasing DR whereas the puncture resistance increased drastically. Finally, the oxygen transmission rate (OTR) of the MDO stretched films could be correlated with the orientation parameters as well as the β-relaxation peak magnitude of the amorphous tie chains. 相似文献