组成,粘度比及加工条件对PB／CS共混物粘度和形态影响

研究了组成，粘度比，转速和混合时间对聚丁烯／玉米浆共混物的粘度和形态的影响。结果表明，共混物的粘度均随速的提高而增大。在高转速下，８０／２０共混物的粘度比其它组成的共混物的粘度增长迅速。     

振动共混对聚丙烯/聚碳酸酯流变性能的影响

在传统转矩流变仪上叠加机械振动制成了振动共混流变仪。实验证明，振动共混降低了70／30聚碳酸酯／聚丙烯共混物的粘度和储存模量，随着制备时的振动振幅和频率的提高，这种效果更加突出。但过大振幅振动中，低剪切与高剪切间的频繁更换，特别是明显的低剪切下相翻转转慢，导致形成了部分不稳定“双连续”相态，这时共混物粘度和模量反而比小振幅振动下制备的共混物的高。一个描述该体系表面张力／液滴半径之比与剪切速率关系的经验表达式较好地分析了流变参数与微观相形态之间的关系，说明了振动促使分散相粒子的破碎和两相的分散，确实影响共混物的相形态。振动共混对聚丙烯／聚碳酸酯流变性能的影响上海交通大学化学化工学院高分子材料研究所，上海　200240振动共混　聚丙烯　聚碳酸酯　流变性能　影响　转矩共混流变仪　相形态在传统转矩流变仪上叠加机械振动制成了振动共混流变仪。实验证明，振动共混降低了70／30聚碳酸酯／聚丙烯共混物的粘度和储存模量，随着制备时的振动振幅和频率的提高，这种效果更加突出。但过大振幅振动中，低剪切与高剪切间的频繁更换，特别是明显的低剪切下相翻转转慢，导致形成了部分不稳定“双连续”相态，这时共混物粘度和模量反而比小振幅振动下制备的共混物的高。一个描述该体系表面张力／液滴半径之比与剪切速率关系的经验表达式较好地分析了流变参数与微观相形态之间的关系，说明了振动促使分散相粒子的破碎和两相的分散，确实影响共混物的相形态。     

增容剂SB对LDPE／PS共混物分散相尺寸的影响

用扫描电镜（SEM）研究了不同混合温芳和转速下增容剂苯乙烯－丁二烯二嵌段共聚物（SB）对低密度聚乙烯／聚苯乙烯（LDPE／PS）共混物分散相颗粒尺寸的影响,结果表明,混合温度为150℃时未增容共混物的分散相颗粒尺寸比200℃时粗大,而在150℃中入SB的共混物的分散相颗粒尺寸比200℃时更精细,在150℃时,转速从30r/min至100r/min至100r/min时,未增容共混物的分散相颗平均半径从3．1um降至0.8um,而增容共混物在30r/min时达到平衡颗粒尺寸0．8um,继续提高转速,颗粒尺寸无明显变化。     

熔体的粘性和弹性对LDPE／PS共混物形态的影响

研究了粘性和弹性对低密度聚乙烯／聚苯乙烯共混物形态的影响。结果表明，不相容聚合物在均匀剪切流动中的分散程度以及分散相的形状与组分的粘度比、相对弹性和体积分数有关。当分散相的粘性和弹性较基相大得多时，随分散相的体积分数增加，球状的液滴形成葡萄串状。若两组分的粘性和弹性相当，在适中的混合比下，分散相产生高度变形。不管组分的粘反比和弹性比大小，若分散相的体积分数非常低，共混物的主要形态皆为分散相的球状液滴分散在基体中。     

PET/PEN扩链反应共混的研究Ⅱ.特性粘度及无规度的变化

对PET／PEN共混体系中共混条件对体系特性粘度的影响作了研究，结果表明，扩链剂的添加，混合温度和时间对[η]有明显的影响，^1H-NMR对共混物无规度的表征表明，体系首先形成嵌段共聚物，随酯交换的进行逐渐向无规共聚物过渡。     

PP-g-MAH对PA6/PP/TLCP三元共混物的增容改性作用

研究了PP-g-MAH对PA6／PP／TLCP三元共混体系的增容作用以及对共混物流变性能和力学性能的影响。通过共混物的DSC、SEM、POM、流变性能和力学性能测试，结果表明，PP－g-MAH对共混体系有明显的增容作用，共混物的力学性能（拉伸强度和冲击强度）得到提高；由于TLCP的加入，共混物的熔体粘度大大低于PA6的熔体粘度。     

HPVC/PP共混改性研究Ⅳ共混物的流变特性

研究了ＨＰＶＣ／ＰＰ共混物的流变性能，结果表明，ＣＰＥ、ＡＢＳ对ＨＰＶＣ／ＰＰ有增粘作用。随着ＣＰＥ用量增加，共混物熔体粘度（ηａ）增加。ＣＰＥ或ＡＢＳ先与ＨＰＶＣ共混后再与ＰＰ共混的共混物的ηａ高于ＣＰＥ或ＡＢＳ先与ＰＰ共混后再与ＨＰＶＣ共混的共混物的ηａ。ＨＰＶＣ／ＰＰ、ＨＰＶＣ／ＰＰ／ＭＡＨ２．５、ＨＰＶＣ／ＰＰ／ＣＰＥ１０、ＨＰＶＣ／ＰＰ／ＡＢＳ１０共混物的ηａ～组成（Ｃ）的关系均属于正－负偏离共混物（Ｐ－ＮＤＢ）体系，即在特定共混比下发生相转变。     

MPE/LLDPE/LDPE共混熔体的流变学

研究了不同比例共混的茂金属聚乙烯（MPE），线性低密度聚乙烯（LLDPE）及高压聚乙烯（20％固定质量配比的LDPE）熔体的流变学行为，讨论了共混物组成，剪切速率和剪切应力以及温度对熔体流变曲线，熔体粘度和膨胀比的影响，为MPE的共混改性加工提供了理论依据，不同共混比的熔体均为假塑性流体，共混熔体的假塑性随LDPE／LLDPE的增多而增强，共混熔体的转变应力和非牛顿指数随LDPE／LLDPE的增加而降低，对加工的敏感性提高，加工性能得到改善。     

HPVC／PP共混改性研究：Ⅲ低分子量反应性化合物作相容剂

采用低分子量反应性化合物作相容剂，即化学交联体系来改善ＨＰＶＣ／ＰＰ共混物的相容性。考察了在不同共混比下，不同化学交联体系对共混物力学性能的影响，并观察了共混物的微观形态。结果表明，采用低分子量反应性化合物作相容剂，共混物的拉伸强度提高，但冲击强度无改善。分散相尺寸减小，相间粘接得到改善。并比较了３种增容方法的效果，发现ＣＰＥ是ＨＰＶＣ／ＰＰ共混物的最佳相容剂。     

线性双峰聚乙烯/高压聚乙烯/线性低密度聚乙烯共混物的流变行为与力学性能

研究了线性双峰聚乙烯(LBPE)、高压聚乙烯(LDPE)与线性低密度聚乙烯(LLDPE)共混物熔体的流变行为和力学性能。讨论了共混物的组成、剪切应力和剪切速率对熔体粘度和膨胀比的影响。结果说明,共混物熔体为假塑性流体,LBPE含量为70％时熔体粘度最大,含量高于60％时挤出胀大变小,含量高于40％时力学强度增大。     

端面混炼挤出机混炼效果的实验研究

采用端面混炼挤出格单螺杆挤出机对ＬＤＰＥ／ＣａＣＯ３，ＬＤＰＥ／ＳＢＳ混合体系进行了挤出混炼效果研究，通过显微照片和图像分析仪对共混物亚微观混炼效果进行数学统计分析，发现端面挤出机混炼效果明显一优于单螺杆挤出机，而端百混炼挤出机端面结构不同，混炼效果也有较大差异，以镶嵌盘混炼效果较佳，研究表明，共混体系分散相物质对发散程度有很大影响，塑性分散相ＳＢＳ粒径远小于固体分散相ＣａＣＯ３的粒径；挤出机转速     

High-shear effects on the nano-dispersed structure of the PVDF/PA11 blends

The fabrication of miscible or nanostructured polymer blends or alloys raises much hope, but poses significant scientific and industrial challenges over the past several decades. Here, we propose a novel strategy using high-shear processing and demonstrate the high-shear effects on the nanodispersed structure formed in the poly(vinylidene fluoride) (PVDF)/polyamide 11 (PAll) blends, in which PA11 domains with a size of several tens of nanometers are dispersed in the PVDF phase. For the blend of PVDF/PA11 = 65/35, the TEM image shows that many nanometer-sized PAl1 particles are dispersed in the PVDF domain to form a special type of domain-in-domain morphology. In contrast, no PVDF nano-dispersion was observed in the PA11 phase. The effects of both the screw rotation speed and the mixing time on the blend structure were systematically studied. It shows that the extruder screw rotation speed and the mixing time are two critical factors to prepare the nanostructured blends. In addition, the investigations on the thermal behavior of the obtained blends indicate the improved miscibility between PVDF and PAl1 by the high shear processing.     

Blending of modified polyphenylene ether with a liquid crystalline copolyester

Blending of poly (2,6-dimethylphenylene ether) (PPE), polystyrene (PS) and a thermotropic liquid crystalline polymer (LCP) was performed using a continuous co-rotating twin-screw extruder. The influence of LCP content on the blending process was studied by changing the barrel heater temperature and the screw speed. The torque of the screw shafts generated during the blending process was influenced by LCP content; its influence was not simple. The generated torque was found to depend not only on the melt viscosity of LCP but also on its distortion temperature. Further, the effects of matrix viscosity on the morphology and mechanical properties of the PPE/PS/LCP blends were studied. Well-developed fine LCP fibrils were formed during the melt-drawing process when the matrix viscosity was high. The formation of well-developed fine fibrils was found to improve the mechanical properties of the PPE/PS/LCP blend. Two mechanisms are proposed for the formation of well-developed fine LCP fibrils.     

Determination of viscosities for alumina–polyethylene blends

The rheology of different proportions of low-density polyethylene (LDPE) and low-density polyethylene wax (LDWAX) without and with alumina was studied and correlated to a model. The viscosities of the polymer blend (LDPE + LDWAX) were studied for various compositions of LDWAX at different temperatures. The Arrhenius plot of logarithmic viscosity and reciprocal temperature for the polymer blends is linear. The enthalpy of viscous flow, determined from the slope of the Arrhenius Plot, varies linearly as a function of the average molecular weight. It is thus possible to predict the viscosity of any intermediate composition of the polymer blend. The viscosities of alumina-polymer blends (AP blend) with 50 vol% of alumina, prepared by solvent method, were also studied as a function of temperature, at a shear rate of 1333.33 s^–1. The AP blends show a lower enthalpy of viscous flow compared to pure polymer blend because of the presence of stearic acid used as surfactant for alumina. The model developed in this study enables the prediction of viscosities of AP blends at any weight average molecular weight (M _w) of the main binder and temperature.     

Microstructural,thermal and rheological correlations to mechanical response of polyamide-6(glass filled)/polyetherimide blend: effect of ethylene-octene copolymer on toughening of blend

Melt mixed glass-filled polyamide 6(PA6)/polyetherimide (PEI) blends were prepared in a co-rotating twin screw extruder over the entire composition range of 0–100 wt% of polyamide 6. These blends were characterized by structural, rheological, mechanical and thermal properties. Crystallization behavior and phase morphology of the blends were also investigated. The blend with the composition PA6/PEI 75/25 showed overall improved mechanical properties along with low resultant viscosity which can be processed on standard equipment. Shear viscosity along with shear stress of the blends were analyzed using shear rheometer which concluded that the blends can be processed on standard equipment due to resultant low viscosity. Scanning electron microscope micrographs revealed that the morphology of the blends showed a two phase structure in which the minor phase was dispersed as domains in the continuous phase. Polyolefin elastomer (POE) as impact modifier was added to the above composition in the range of 0–15 phr to study its effect. The thermal characteristics of PA6, PEI, and PA6/PEI blends with and without POE were investigated using DSC and TGA which revealed that the melting temperature and crystallization temperature of the blend remained unchanged while XRD results showed percent crystallinity was increased slightly. Furthermore, it can be said that the blend with composition PA6/PEI 75/25 with 10 phr impact modifier loading was suitable for high end applications because it combines the high mechanical properties of glass-filled PA6 with inherent flame-retardant property of PEI while POE overcomes the physical weakness of moisture absorption.     

超韧尼龙6体系的流变与力学行为EI

马来酸酐接枝聚烯烃类热塑弹性体 (TPEg)对尼龙 6有显著的增韧效果。研究了基体粘度和界面改性剂 (CE-96 )的使用对尼龙 6 / TPEg共混体系缺口冲击强度的影响。在 TPEg分散相粘度大于尼龙 6基体粘度情况下 ,TPEg对高粘度尼龙 6的增韧效果明显好于低粘度尼龙体系。CE- 96的加入通过增大尼龙 6基体粘度和增强界面偶联显著地改善了 TPEg分散质量。在给定的分散相含量下 ,分散相颗粒尺寸的减小更有利于引发基体剪切屈服 。     

用SEM观察PE/PC共混物在拉伸和冲击作用前后的形态

介绍了典型的极不相容共混物（ＥＩＢ）聚乙烯／聚碳酸酯（ＰＥ／ＰＣ）体系的形态受组成的影响,以及共混物在受到拉伸前后,冲击前后的形态。通过扫描电子显微镜（ＳＥＭ）观察发现,组成不仅影响分散相粒子的大小,形状,还决定分散相与连续相的转变,共混物在受到拉应力（拉伸）和剪切应力（冲击）后,前者较多球状粒子变形成为有利于提高拉伸性能的纤维状,后者粒子和基体都发生了能提高抗冲击韧性的塑性变形。     

PES/TLCP共混物的加工性能及其原位增强特性

本文分析了TLPC与PES及其共混物的流变特性和相容性,通过注塑和双螺杆共混物挤出拉伸来研究上述共混物的原位增强特性。结果表明,共混物粘度比TLCP和PES的粘度要低,液晶的加入有效地改善了加工性能;共混体系中液晶与PES几乎不相容;PES及其共混物的粘度较高,注塑性能较差,而比较适合于双螺杆共混挤出拉伸加工;液晶含量的增大使共混物熔体粘度下降,拉伸强度提高,脆性增大;随着熔体拉伸比的增大,复合丝拉伸强度大幅度提高,达到了良好的原位增强效果。     

STUDY OF DEGRADATION KINETICS OF BLENDS OF EPOXY AND RESOLE: A STATISTICAL APPROACH

Blends of resole and epoxy were prepared by physical mixing, and cured with 30% polyamide based on blend resin and polyamide. Degradation of each sample was studied by dynamic thermogravimetric analysis in nitrogen atmosphere at a heating rate of 10°C min^-1. The degradation of blends of epoxy and resole having 30 wt % polyamide proceeded with 0.50th order. This result was found with the Coats-Redfern equation using best-fit analysis, and further confirmed by linear regression analysis. The validity of data was checked by t test analysis. From this value of reaction order, activation energy (E) and pre-exponential factor (Z) were calculated. The values of activation energy increased, whereas the values of pre-exponential factor decreased as the resole content in the blend decreased from 100 to 0 wt %.