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以回收聚对苯二甲酸乙二醇酯(rPET)为基体材料,茂金属线型低密度聚乙烯(mLLDPE)为共混材料,马来酸酐接枝线型低密度聚乙烯(LLDPE-g-MAH)、丙烯酸酯复合接枝苯乙烯-丁二烯弹性体为相容剂,制备了rPET/mLLDPE共混物。采用DSC和SEM分析了相容剂对共混物结晶性能及断面结构的影响,并检测了共混物的力学性能。结果表明:mLLDPE的加入使得rPET/mLLDPE共混物的熔体结晶峰向右移动,结晶温度提高了29.03℃;相容剂的加入使得共混物中rPET的玻璃化转变温度向低温方向移动,rPET与mLLDPE相容性增强;含3%LLDPE-g-MAH的rPET/mLLDPE共混物中,MAH基团与rPET中的羟基发生接枝反应,相界面模糊,rPET与mLLDPE界面黏结力增强,与纯rPET相比,其断裂伸长率提高了93.73%,缺口冲击强度提高了54.6%。 相似文献
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以回收聚对苯二甲酸乙二酯(rPET)瓶料为基体材料,茂金属线性低密度聚乙烯(mLLDPE)为增韧材料,马来酸酐接枝(乙烯/辛烯)共聚物(MAH-g-POE)为增容剂,制得rPET/mLLDPE/MAH-g-POE复合材料.研究表明,mLLPE的加入使得rPET的结晶温度提高,与纯rPET相比,含质量分数5%MAH-g-POE的rPET/mLLDPE/MAH-g-POE复合材料的结晶温度提高24.39%,缺口冲击强度提高216.6%,断裂伸长率提高14.54倍;MAH-g-POE使rPET/mLLDPE中rPET的玻璃化转变温度向低温方向移动,rPET与mLLDPE的相容性提高,界面粘结力增强,熔融塑化时的扭矩增大. 相似文献
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研究了茂金属线型低密度聚乙烯(mLLDPE)、mLLDPE/低密度聚乙烯(LDPE)共混物的热性能、流变性能及薄膜样品的基本性能。热性能结果表明,在mLLDPE中添加LDPE使样品的结晶温度明显下降;毛细管流变试验结果表明,LDPE的添加使mLLDPE的剪切敏感性显著提高,利于其加工;薄膜样品性能研究结果表明,mLLDPE使得LDPE的力学性能明显提高,光学性能明显改善。 相似文献
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以低密度聚乙烯(LDPE)为基体材料,聚偏氯乙烯(PVDC)为共混材料,马来酸酐接枝低密度聚乙烯(LDPE-g-MAH)为相容剂,采用挤出和注塑成型方法制备LDPE/PVDC/LDPE-g-MAH共混物,考察了共混物的力学性能、阻隔性能、热性能和微观形态结构。结果表明:加入25%PVDC,LDPE/PVDC共混物的熔融温度下降了1.79℃,吸油率降低了9.66%,物理力学性能明显下降;加入LDPE-g-MAH后,LDPE和PVDC之间的界面黏结力增强,相容性提高,结晶温度和结晶度略有下降;与纯LDPE相比,含3%LDPE-g-MAH的LDPE/PVDC共混物的断裂伸长率提高了11.63%,缺口冲击强度提高了13.35%,吸油率下降了16.29%,柔韧性和阻隔性明显提高。 相似文献
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本工作研究了茂金属线型低密度聚乙烯(mLLDPE)/低密度聚乙烯(LDPE)共混物的流变性能及所制薄膜性能.结果表明:mLLDPE的加工性能较差,w(LDPE)为20%即可明显改善mLLDPE的加工性能,随着LDPE用量的增加,mLLDPE/LDPE共混物的加工性能改善更为明显;随着w(mLLDPE)的增加,用mLLD... 相似文献
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杨柳 《现代塑料加工应用》2007,19(2):34-36
利用差示扫描量热仪(DSC)研究了茂金属线性低密度聚乙烯(mLLDPE)和传统线性低密度聚乙烯(LLDPE)的非等温结晶行为。采用Jeziorny法和莫志深法对所得的数据进行了分析。结果表明,采用莫志深法处理数据可得到较好的线性关系,且mLLDPE在相同的相对结晶度下的结晶速率低于LLDPE。 相似文献
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用傅立叶红外光谱(FTIR)、力学性能测试等方法研究了聚烯烃离聚体原位增容聚丙烯/线性低密度聚乙烯(PP/LLDPE)共混物。结果表明:熔融状态下,在马来酸酐接枝聚丙烯/马来酸酐接枝线性低密度聚乙烯(PP-g-MAH/LLDPE-g-MAH)(质量比50/50)共混物中加入二水醋酸锌,共混物中的马来酸酐基团(羧酸基团)与Zn2+发生离子偶联反应,相界面就地产生的聚烯烃离聚体增加了两相界面黏合力,共混物力学性能提高;原位增容后共混物中的PP和LLDPE相熔点略微下降,LLDPE结晶温度向高温移动;在角频率为0.01~100.00s-1,原位增容后共混物的储能模量、损耗模量和复数黏度都高于简单共混物的,损耗正切(tanδ)低于简单共混物的;对于PP/PP-g-MAH/LLDPE/LLDPE-g-MAH四元体系,SEM显示原位增容后共混物的相界面变得模糊,相容性提高。 相似文献
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The influences of ultrasonic oscillations on rheological behavior and mechanical properties of metallocene‐catalyzed linear low‐density polyethylene (mLLDPE)/low‐density polyethylene (LDPE) blends were investigated. The experimental results showed that the presence of ultrasonic oscillations can increase the extrusion productivity of mLLDPE/LDPE blends and decrease their die pressure and melt viscosity during extrusion. Incorporation of LDPE increases the critical shear rate for sharkskin formation of extrudate, crystallinity, and mechanical properties of mLLDPE. The processing behavior and mechanical properties of mLLDPE/LDPE blends were further improved in the presence of ultrasonic oscillations during extrusion. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2522–2527, 2004 相似文献
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The crystalline structure and phase structure of metallocene linear low density polyethylene (mLLDPE) and low density polyethylene (LDPE) blends were investigated, using a combination of differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), and small-angle X-ray scattering (SAXS) techniques. The samples displayed cocrystallization phenomenon for LDPE of 80 wt% in the blends, indicating good compatibility between the two components under this circumstance; as LDPE content decreased, phase separation arose whereas partial cocrystallization still existed in the blends. Over the whole range of weight fractions, the intrinsic crystal structure of mLLDPE does not change with the addition of LDPE, while enhanced orthorhombic crystalline phase were observed as LDPE content increased. The changes in the thickness of interface layer σb, dispersed phase size ac and integral invariant Q further indicate the existence of partial compatibility between the two phases. Irrespective of the phase inversion, the morphology of the dispersed phase is deduced to be in a transitional state from rod-like shape to flakes within the whole proportional range investigated. 相似文献
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茂金属线型低密度聚乙烯的结构与性能 总被引:2,自引:0,他引:2
利用傅里叶变换红外光谱、凝胶渗透色谱、差式扫描量热法和力学性能测量等手段表征了茂金属线型低密度聚乙烯(mLLDPE)和传统线型低密度聚乙烯(LLDPE)的结构及性能,用热分级法表征了LLDPE的片晶厚度多散性,测试了mLDPE薄膜的相关性能。结果发现,mLLDPE的片晶厚度分布指数为1.1347,小于传统LLDPE,表明其具有更好的支化均匀性,但其相对分子质量分布窄;mLLDPE薄膜具有较高的落镖冲击强度、撕裂强度、热封强度和突出的光学性能。 相似文献
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The melting/crystallization behavior and isothermal crystallization kinetics of polypropylene (PP)/metallocene-catalyzed linear
low density polyethylene (mLLDPE) blends were studied with differential scanning calorimetry (DSC). The results showed that
PP and mLLDPE are partially miscible and interactions mainly exist between the mLLDPE chains and the PE segments in PP molecules.
The isothermal crystallization kinetics of the blends was described with the Avrami equation. Values of the Avrami exponent
indicated that crystallization nucleation of the blends is heterogeneous, the growth of spherulites is almost three-dimensional,
and the crystallization mechanism of PP is not affected much by mLLDPE. The Avrami exponents of the blends are higher than
that of pure PP, showing that the mLLDPE helps PP to form perfect spherulites. The crystallization rates of PP are decreased
by mLLDPE because the crystallization temperature of PP was decreased by addition of mLLDPE and consequently the supercooling
of the PP was correspondingly lower. The crystallization activation energy was estimated by the Friedman equation, and the
result showed that the activation energy increased by a small degree by addition of mLLDPE, but changed little with increasing
content of mLLDPE in the blends. The nucleation constant (K
g) was determined by the Hoffman–Lauritzen theory.
Supported by the Science Foundation of Hebei University (2006Q13). 相似文献
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以自制接枝共聚相容剂,将回收聚对苯二甲酸乙二醇酯(rPET)分别与全新线性低密度聚乙烯(PE?LLD)和回收聚乙烯(rPE?HD)共混改性,采用具备免干燥和侧面强制喂料系统的同向双螺杆挤出机熔融挤出rPET/PE合金片材(rPET与PE质量比为80∶20),研究了不同厚度合金片材的性能。结果表明,使用rPET制备的合金片材产品外观品质保持较好; rPET/PE合金片材具有良好的力学性能,其中拉伸强度大于39 MPa,断裂伸长率随片材厚度增加而递减,厚度为2.5 mm的rPET/rPE合金片材拉伸强度为39.7 MPa,断裂伸长率为21 %,冲击强度为12 kJ/m2,适合应用于吸塑箱包、土工格室等;免干燥和侧面强制喂料系统,可以减少合金片材加工流程,节约能源,设备产量提了117 %。 相似文献