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茂金属聚乙烯的共混改性研究 总被引:3,自引:2,他引:3
对三种茂金属聚乙烯 (mPE)做了DSC研究。将茂金属聚乙烯同传统聚烯烃 (HDPE ,PP ,LDPE)进行了共混研究 ,结果表明mPE的加入提高了LDPE的拉伸性能 ,使HDPE和PP的拉伸强度下降 ,但mPE含量在 2 0 %~2 5 %的范围内 ,拉伸强度和断裂伸长率下降很小。mPE的加入大大提高了PP和HDPE的冲击性能。对mPE/LDPE共混物吹膜进行了研究 ,测定了共混物的熔体流动速率 ,探索了吹膜的工艺条件 ,以及薄膜的拉伸性能、撕裂性能与共混组成比的关系。 相似文献
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用毛细管流变仪研究了茂金属聚乙烯蜡改性聚乙烯共混体系的流变行为,探讨了茂金属聚乙烯蜡用量对共混体系熔体流变行为、熔体黏度、非牛顿指数和流动活化能的影响。结果表明:茂金属聚乙烯蜡对LLDPE/LDPE流动黏度降低明显,增加用量可使黏度逐渐降低;而对MPE/LLDPE/LDPE共混体系流动行为的影响比较复杂,在低剪切应力下黏度随茂金属聚乙烯蜡用量增加而逐渐降低,而在高剪切应力下黏度先增后减;茂金属聚乙烯蜡与MPE/LLDPE/LPDPE的相容性好于LLDPE/LDPE共混体系。 相似文献
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研究了茂金属聚乙烯结构,发现茂金属聚乙烯(mPE)具有比传统聚乙烯更规整的结构、更窄的分子量分布;指出:通过改进mPE的合成技术,使用复配催化剂生产双峰或宽峰聚乙烯,改进树脂加工设备等手段可以制得性能优良的茂金属乙烯制品。 相似文献
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综述了茂金属催化剂的发展和茂金属聚乙烯(mPE)产品的工业化现状,国内外mPE生产工艺、产品牌号、应用领域及国内mPE开发现状。茂金属催化剂活性高,可精确定制聚乙烯树脂的分子结构,用其制备的聚乙烯具有较窄的相对分子质量分布。限制几何构型催化剂技术与溶液聚合工艺相结合可以在分子结构上控制短支链和长支链在主链上的分布及产品的相对分子质量分布。我国茂金属催化剂及mPE在研发和生产方面与国外公司差距较大,尤其薄膜晶点问题未能解决,影响了在薄膜领域的应用,因此,加快mPE产品的研发与生产十分必要。 相似文献
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为改善高流动性聚丙烯(HF-PP)的性能,采用茂金属乙烯-己烯共聚物(mEHC)和茂金属乙烯-丁烯-己烯三元共聚物(mEBHC)进行改性,通过熔融共混法制得mEHC/HF-PP和mEBHC/HF-PP共混物。研究了mEHC和mEBHC对HF-PP熔体流动速率和流变行为的影响。结果表明,mEHC/HF-PP和mEBHC/HF-PP共混物的非牛顿指数小于1;随着共混物中mEHC和mEBHC含量的增加,共混物的熔体流动速率下降,表观黏度逐渐升高;mEHC/HF-PP和mEBHC/HF-PP比纯HF-PP具有更强的黏温敏感性。 相似文献
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The main objective of this study is to investigate the barrier mechanisms and properties of polyethylene, polyethylene (PE)/polyamide (PA) and polyethylene/modified polyamide (MPA) bottles against paint solvent permeation. In addition to the paint mixed solvent, the barrier properties of these bottles against the permeation of pure main solvents contained in the paint mixed solvent were investigated to understand the permeation mechanisms of the paint solvents. The paint solvent permeation resistance improves dramatically after blending PA and MPA barrier resins in PE matrices during blow‐molding. In fact, by using proper compositions, the white spirit permeation rates of PE/MPA and PE/PA bottles at 40°C are about 360 and 50 times slower than that of the PE bottle, respectively. Further investigations showed that, after blending the MPA and PA barrier resins in PE matrices, the hydrocarbon solvents present in the white spirit were nearly blocked without permeation during the permeation tests, i. e., PE/MPA bottles inhibited the permeation of hydrocarbon solvents more successfully than PE/PA bottles. In contrast, the rates of polar solvents with ketone, ether and alcohol functional groups permeating through the PE bottles are much slower than that of the white spirit and only slightly faster than those through the PE/PA and PE/MPA bottles. On the other hand, the paint mixed solvent permeation rates of PE bottles are approximately equal to the summation of permeation rates of the solvents present in mixed solvents calculated using a simple mixing rule. Somewhat surprising, the permeation rates of mixed solvents of PE/MPA bottles are dramatically faster than those calculated using a simple mixing rule, when the polar solvent contents are in a certain range. 相似文献
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The physicomechanical properties of polymer blend formulations comprising different grades of metallocene-catalyzed linear low-density polyethylenes (mLLDPEs) with high-density polyethylenes (HDPEs) or a low-density polyethylene (LDPE) were investigated. For blends with HDPE, the addition of mLLDPE improves the Izod impact strength and some tensile properties. For blends with LDPE, adding mLLDPE increases the ductility and the percent elongation at break. 相似文献
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为改善高流动性聚乙烯(HF-PE)的性能,采用茂金属乙烯-丁烯共聚物(mEDC)进行改性,通过熔融共混法制得mEDC/HF-PE共混物。研究了mEDC/HF-PE共混物的流变行为、力学性能、结晶性能,并和国内外HF-PE的性能进行比较。结果表明:mEDC改性HF-PE专用料结晶温度和熔融温度稍高于7200HF-PE和52518HF-PE的,力学性能与7200HF-PE的相当,熔体流动速率(MFR)大于7200HF-PE和52518HF-PE的,相同温度下黏度均小于7200HF-PE和52518HF-PE的,在高剪切速率下具有高的温度敏感性,具有好的流动性和加工性能。 相似文献
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聚乙烯副产物中稀释剂和聚乙烯蜡的提取 总被引:2,自引:0,他引:2
以辽阳石油化学纤维公司化工三厂高密度聚乙烯副产原料,采用水蒸汽蒸馏的方法,分离得到稀释剂和低分子量聚乙烯。讨论了各种工艺条件变化对蒸馏质量的影响。确定了分离的最佳工艺条件。 相似文献
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本实验采用吹塑成型工艺,以不同牌号的聚乙烯(PE)树脂为原料生产2 mm厚度双光面高密度聚乙烯(HDPE)土工膜,研究PE原料对HDPE土工膜性能的影响。结果表明:中密度聚乙烯(MDPE)土工膜综合性能优异,主要是由其特有的分子结构(如分子量分布双峰性、α烯烃长支链)所决定的;不同PE原料氧化诱导时间不同,可通过调节含抗氧剂色母料(或抗氧剂)的含量,使HDPE土工膜氧化诱导时间达到要求;HDPE土工膜在焊接时应根据PE材质的不同而选择不同的焊接条件。 相似文献
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通过DSC、SEM和动态流变法分析超高分子量聚乙烯/高密度聚乙烯(UHMWPE/HDPE)共混物的相容性。结果表明:UHMWPE和HDPE具有良好的相容性。UHMWPE/HDPE共混物是典型的假塑性流体,当HDPE的质量分数逐渐增大,共混物的复数黏度明显减小,其流动性变好。UHMWPE能够显著提高共混物的低温冲击性能,当UHMWPE含量超过40%,共混物在-60℃的缺口冲击强度在70 kJ/m2以上。当UHMWPE含量为50%,共混物的熔体流动速率为0.12 g/10min,-60℃缺口冲击强度达到77 kJ/m2,使加工性和低温冲击性能达到平衡。 相似文献
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