电子辐照HDPE对HDPE／PET的增容作用

通过用电子束辐照高密度聚乙烯(HDPE),引入极性基团到HDPE中,增加了HDPE与聚对苯二甲酸乙二醇酯(PET)共混体系的相容性。辐照的HDPE与PET共混,使共混转矩和比能量消耗增加;但HDPE辐照一个月后再与PET共混,则使共混转矩和比能量消耗降低。力学性能数据表明,辐照的HDPE对HDPE/PET共混体系具有增容作用。     

SEBS/HDPE共混物加工性能及力学性能的研究

以苯乙烯-乙烯-丁二烯-苯乙烯嵌段共聚物（SEBS）／高密度聚乙烯（HDPE）为共混改性的研究对象，采用哈克转矩流变仪进行共混，讨论了不同用量、不同类型的HDPE对共混物加工流变性能、冲击性能和拉伸性能的影响。结果表明，当添加的HDPE份数达到20phr时，能显著提高共混物的冲击性能和拉伸性能，同时共混物的加工流变性能也有了很大的改善。因此质量比为100／20的SEBS／HDPE体系是一个比较理想的共混体系。     

不同润滑剂对HDPE流变性能的影响

利用RH2200恒速型毛细管流变仪考察了硬脂酸镧复合物（RC）分别和聚乙烯蜡共混前后对高密度聚乙烯（HDPE）挤出性能的影响。与纯HDPE5000S相比，加入1．5份RC和1．0份或3．0份聚乙烯蜡混合物以后，熔体的表观粘度降低，发生压力振荡时候的滑移长度减少以及信号强度明显消失。     

HDPE／NBR共混物流变性能研究

通过熔融共混法制备了HDPE／NBR共混物,用毛细管流变仪研究了其流变特性,此共混物属于假塑性流体,表观粘度随剪切速率和温度的升高而降低,随NBR和增容剂含量的降低而降低。     

γ射线辐照对HDPE/PA6共混体系的影响

采用FTIR、Molau实验，SEM，力学性能及阻隔性能测试方法，研究了γ射线辐照对高密度聚乙烯（HDPE）／尼龙6（PA6）共混体系的影响，结果表明，采用γ射线对HDPE进行辐照，在其分子链上引入了含氧极性基团，增加了HDPE分子的极性，改善了HDPE／PA6共混体系的相容性，提高了该共混体系的力学性能和对二甲苯的阻隔性能。     

聚氯乙烯／丁腈橡胶共混型热塑性弹性体流变性能的研究

采用毛管流变仪研究了聚氯乙烯（ＰＶＣ）／丁腈橡胶（ＮＢＲ）共混型热塑性弹性体的流变性能。试验结果表明，ＰＶＣ／ＮＢＲ热塑性弹性体熔体是一种典型的假塑性流体，并遵从幂律流体规律。橡胶含量和硫黄用量降低或增塑剂ＤＯＰ用量增加均可降低熔体的表观粘度。采用高速混炼和返炼的方法，可使熔体粘度减小，挤出物外观质量明显改善。     

相容共混物熔体的平衡转矩与组成关系的探讨

以熔体指数不同的高密度聚乙烯(HDPE)和均聚聚丙烯(PP)为试样,利用MiniLab微型混合流变仪,研究了在熔融状态下完全互容的HDPE/HDPE、PP/PP和HDPE/PP共混物熔体的平衡转矩随组成的变化规律。结果表明:相容共混体系的熔体平衡转矩-组成关系曲线一般表现为线性或者二次抛物曲线。当高分子链的化学结构单元不同时,其共混熔体的平衡转矩-组成关系多为二次抛物曲线。     

高流动性PP增韧体系流变性能的研究

利用毛细管流变仪和转矩流变仪对高流动性聚丙烯（PP）增韧体系的流变性能进行分析,讨论了聚烯烃弹性体（POE）、三元乙丙橡胶（EPDM）=增韧母料和降温母料等助剂对高流动性PP共混体系流变性能的影响,并对PP/POE共混体系和PP/EPDM共混体系的转矩流变曲线进行了对比,考察了不同共混体系的微观结构、力学性能和加工性能。     

HDPE/E-TMB共混物熔体的流变行为研究

用自制增韧母料(ETMB)与高密度聚乙烯(HDPE)通过热机械共混制得增韧高密度聚乙烯(HDPE/ETMB)共混物,用高压毛细管流变仪对此类共混物的流变行为进行了研究。结果表明,HDPE/ETMB共混物为假塑性流体;表观粘度随剪切速率和切应力的增大而减小,并随温度的升高而降低;粘流活化能随剪切速率的增大和母料中乙丙弹性体含量的增加均呈逐渐减小的趋势。     

碳纳米管/HDPE复合材料的制备及性能研究

将酸化处理以后的碳纳米管（CNTs）与高密度聚乙烯（HDPE）复合，采用机械共混法制备了定向CNTs／HDPE复合材料，并对其力学性能、相态结构、流变性能及热性能进行了研究。结果表明：CNTs的加入，提高了复合材料的屈服强度和拉伸模量，但同时却降低了材料的断裂强度和断裂伸长率；CNTs在HDPE基体中有了较好的分散性和相容性；CNTs的加入对复合材料流变性能产生了较大的影响，加入少量的CNTs可以使复合材料体系的表观粘度降低，有利于HDPE加工性能的改善；CNTs加入后，HDPE的熔融温度和结晶熔融焓均有所下降。     

PP/HDPE共混体系毛细管流变性能研究

用毛细管流变仪对以马来酸酐接枝聚丙烯(PP-g-MAH)为相容剂的聚丙烯/高密度聚乙烯(PP/HDPE)共混体系的流变性能进行研究。研究发现,PP/HDPE共混体系属于假塑性流体;随着剪切速率的增加,表观黏度下降;PP-g-MAH的加入降低了共混体系的表观黏度;HDPE与PP的非牛顿指数在低剪切速率区与适宜温度下适用于幂律方程的经验公式;HDPE与PP共混后,HDPE含量越低,体系出现壁面滑移的临界剪切速率越高,可加工性能越好。     

氟聚合物加工助剂在HDPE挤出中的应用初探

通过毛细管转矩流变仪对氟聚合物加工助剂在HDPE挤出中的研究试验发现,在HDPE挤出中加入含氟聚合物加工助剂(PPA),可以极大地降低体系的出口压力;同时使体系的粘度也有所降低,提高挤出效率。试验还发现,含氟聚合物加工助剂PPA与分散剂共用,有利于建立平衡时间的缩短,对加工转矩和体系粘度的影响不明显。     

Processability and thermal properties of blends of high density polyethylene,poly (ethylene terephthalate), and ethyl vinyl acetate compatibilizer

Because of differences in chemical structure and rheological characteristics, high density polyethylene (HDPE) and poly(ethylene terephthalate) (PET) are incompatible when blended during recycling of PET soft drink bottles. To improve the properties of the blends, ethylene vinyl acetate copolymer (EVA) was used as a compatibilizer. Based on torque rheometer tests, the higher the concentration of PET in the blends, the higher the initial loading torque. Blends of 50% HDPE and 50% PET had the lowest equilibrium torque. Equilibrium torque was highest at 5% EVA. The presence of EVA made only a slight difference in the glass transition temperatures of HDPE/PET blends. Higher EVA content in the blend resulted in a lower melting endotherm. Thermogravimetric analysis showed that thermal stability was independent of EVA content; but the more PET in the blend, the lower the final weight loss.     

定向碳纳米管/高密度聚乙烯复合材料体系流变行为的研究

对定向碳纳米管进行酸化处理以后，采用机械共混法制备了定向碳纳米管／高密度聚乙烯复合材料，利用毛细管流变仪研究了高密度聚乙烯和定向碳纳米管／高密度聚乙烯复合材料的流变行为．讨论了剪切应力、剪切速率、温度以及定向碳纳米管的加入对体系流变行为的影响。结果表明：高密度聚乙烯和定向碳纳米管／高密度聚乙烯复合材料都属于假塑性流体．高密度聚乙烯的非牛顿性要大于定向碳纳米管／高密度聚乙烯复合材料；随剪切速率和剪切应力的增大及温度的升高．熔体表现粘度均减小；随着定向碳纳米管含量的增加，定向碳纳米管／高密度聚乙烯复合材料的表观粘度先减小后增大。     

Studies on dynamic behaviour and flow properties of HDPE/EPDM blends by torque rheometer

The effect of blend ratio on the crosslinking characteristics and dynamic elastic properties of HDPE/EPDM blends was studied by a torque rheometer. The crosslink density (a measure of tensile strength) first increases and then decrease with increase in EPDM content. The dynamic elastic property (a measure of impact strength) also showed a peculiar trend. Both studies showed that less than 40 parts loading of EPDM gave the best mechanical properties. In another study the flow activation energy was calculated by temperature programming, which gave the value of processing temperatures (cold mixing, hot mixing).     

Effect of interfacial interaction on the mechanical properties of electron beam irradiated HDPE/STC blend

Some oxygen‐containing groups (mainly C?O group) are introduced on the molecular chain of HDPE during electron beam irradiation in air. The affinity between HDPE and sericite–tridymite–cristobabite (STC), the dispersion of STC in HDPE matrix are improved owing to the polar groups introduced. By treating STC with amino‐containing silane coupling agent, the interfacial adhesion between irradiated HDPE (e‐HDPE) and treated STC (t‐STC) is further improved, the mechanical properties of e‐HDPE/t‐STC blend are improved quite a lot. The experimental results show that due to the improvement of interfacial interaction, the interfacial phase can transmit the stress subjected to the HDPE matrix and make the matrix absorb energy by plastic yield or deformation; the impact strength of e‐HDPE/t‐STC blend is thus improved. © 2002 John Wiley & Sons, Inc. J Appl Polym Sci 84: 814–820, 2002; DOI 10.1002/app.10345     

HDPE管材专用树脂的流变性能

应用动态流变仪、毛细管流变仪和转矩流变仪,对新型双峰高密度聚乙烯(HDPE)管材专用树脂 6380 M进行流变性能测试分析,并与国内外相同压力等级的HDPE管材专用树脂进行比较。结果表明,6380 M的各种流变性能与进口管材专用树脂相当,而与单峰HDPE管材专用树脂相比具有弹性模量低、零切黏度低、拉伸黏度低的流变特性,从而对其加工性能产生影响。6380 M流动性好,其临界剪切速率高,但熔体强度不及单峰HDPE。     

Flow Behavior of Polypropylene/Ethylene-Propylene Diene Terpolymer/Natural Rubber (PP/EPDM/NR) Blends by Torque Rheometer: The Effect of N,N-m-Phenylene Bismaleimide (HVA-2) Addition

Blends of polypropylene (PP)/ethylene-propylene diene terpolymer (EPDM)/natural rubber (NR) with different ratio were investigated using a Haake torque rheometer. The effect of N,N-m-phenylene bismaleimide (HVA-2) addition on the flow behavior of PP/EPDM/NR blends also was studied. The torque data was collected at different rotor speeds in the range of 30–60 rpm and different processing temperatures in the range of 170–190°C. The recorded data were interpreted in terms of apparent shear rate, apparent shear stress, and apparent viscosity. The shear stress–shear strain curve shows that all blends follow the power law where the pseudoplasticity behavior of melt viscosity increases with increasing NR content as well as addition of HVA-2. The apparent viscosity of the blends was found to increase with increasing NR content in the blend. The addition of HVA-2 increases the apparent viscosity due to the formation of cross-linking in rubber phase. However, blends with HVA-2 show lower flow activation energies than do similar blends without HVA-2. Scanning electron microscopy (SEM) shows good correlation with the flow properties of the blends.     

Effects of the blending sequence in polyolefin ternary blends

Ternary blends of isotactic polypropylene (PP), ethylene–octene copolymer (mPE), and high‐density polyethylene (HDPE) were prepared by melt mixing in a twin‐screw extruder with two different sequences of mixing: the simultaneous mixing of the three components (method I) and the premixing of mPE and HDPE followed by mixing with PP (method II). Regardless of the mixing sequence, mPE encapsulated HDPE in the PP matrix, although better mechanical properties were generally obtained with method II. The domain size was mainly determined by the viscosity ratio of mPE to PP in method I and by the viscosity ratio of the binary blend (mPE/HDPE) to PP in method II. Specimens prepared by injection molding gave much finer dispersions than compression‐molded specimens. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 804–811, 2004