NP-10/硝酸钠水溶液体系的相行为与流变性

研究了浓度为0.02mol/L的硝酸钠水溶液中非离子表面活性剂NP-10的相行为与流变学性质。随NP-10质量分数的增加,体系中依次可以形成胶束,六角状、立方状和层状液晶以及反胶束。六角状和立方状液晶的流变学性质可以用Maxwell模型说明。用已经验证的经验方程对层状液晶的流变学特征做出了表述。     

Phase Behavior of Polyelectrolyte Complexes and Rheological Behavior of Alumina suspensions for Direct Ink Writing

Polyelectrolyte complexes have a bright prospect for fabricating 3D periodic structures by direct ink writing. The phase behavior of complexes containing poly(acrylic acid) and poly(ethylenimine) and rheological behavior of Al₂O₃ colloidal suspensions are characterized. The results reveal that the pH value of solution takes an important role on the phase behavior of polyelectrolyte complexes. When the [COOH]:[NH_x] ratio is higher than or lower than the critical value of 0.6, the pH range of turbid complex solutions narrows down and meanwhile moves to acidic or alkaline region, respectively. The addition of pH regulators prompts polyelectrolyte exchange reaction and soluble complexes are suitable for preparation of cera‐mic suspensions. The polyelectrolyte suspensions with linear viscoelasticity at lower shear stress and good fluidity at higher shear stress are identified for direct ink writing of 3D structures with microsized feature.     

聚苯硫醚流变行为研究

采用高压毛细管流变仪研究了进口聚苯硫醚(PPS)树脂的流变性能,分析了剪切速率、温度对PPS树脂流变行为的影响。结果表明,PPS树脂的非牛顿指数均小于1;在低剪切速率下,PPS树脂的表观黏度对温度的依赖程度高于高剪切速率下的依赖程度;PPS树脂的黏流活化能随剪切速率的增加呈减小趋势,其结构黏度指数随温度升高而减小。     

氢氧化镁阻燃EVAC的流变性能研究

采用熔融共混法制备了Mg(OH)2阻燃乙烯-乙酸乙烯酯塑料(EVAC),并采用毛细管流变仪对其流变性能进行了研究。讨论了温度、剪切速率和剪切应力对熔体表观黏度的影响;研究了黏流活化能与剪切速率的变化规律。结果表明,熔体的表观黏度随温度的升高而降低,随剪切速率和剪切应力的增大而减小;黏流活化能随剪切速率的增大而降低。其非牛顿指数小于1,说明Mg(OH)2阻燃EVAC为假塑性流体。当剪切应力无限小时,由Spencer-Dillon公式外推得到阻燃EVAC的零切黏度。     

Rheological Behavior of Poly(m-phenyleneisophthalamide) in Ionic Liquid

Summary The rheological behavior of poly(m-phenyleneisophthalamide) (PMIA) in 1-n-butyl-3-methylimidazolium chloride ([Bmim]Cl, ionic liquid) has been investigated. The polymer in the concentration range investigated exhibits very different behavior between [Bmim]Cl and DMAc/LiCl solvent. Unlike in DMAc/LiCl solvent, PMIA/[Bmim]Cl solution exhibits maxima in apparent viscosity-concentration plots in the range studied. The complex viscosity-frequency behavior of the PMIA/[Bmim]Cl solutions is similar to that steady-state rheological behavior. The different rheological behavior shows the interaction between macromolecule and IL which leading the supermolecular aggregates in PMIA/[Bmim]Cl solution.     

ABS/PETG双连续相形态及流变性能研究

通过熔融共混方法制备高分子合金丙烯腈-丁二烯-苯乙烯共聚物(ABS)/聚对苯二甲酸乙二醇酯-1,4-环己烷二甲醇酯(PETG),采用扫描电镜(SEM)和旋转流变仪对该共混物形态和流变性能进行详细而系统的研究。SEM结果表明,ABS和PETG属于不相容体系,且ABS含量在50%～60%之间,ABS和PETG可形成双连续相结构。流变实验也证实了这个结论。提高剪切速率(40 s-1以上)可以大幅度降低ABS黏度,但是对PETG影响很小,所制备的ABS/PETG共混物对剪切速率变化敏感;与高含量ABS(≥50%)相比,低含量的ABS(≤50%)的共混物,具有较高的储能模量、损耗模量和复合黏度,表明低含量的ABS共混物强度较高,韧性较差。     

PBT/ASA共混体系相形态及流变性能研究

通过熔融共混技术将丙烯腈苯乙烯丙烯酸酯三元共聚物(ASA)对聚对苯二甲酸丁二醇酯(PBT)进行了增韧改性,并采用扫描电子显微镜、动态流变分析仪观察研究了PBT/ASA共混体系的相形态和流变行为。结果表明,ASA可有效增加PBT共混体系的熔体强度,所形成的PBT/ASA共混物为部分相容体系;体系的相容性具有一定的组分依赖性,当ASA含量较低时,共混体系为典型的“海岛”结构,而当ASA含量为40 %～60 %（质量分数,下同）时体系发生了相翻转,该结果与4个预测相翻转的模型中HoRM模型计算得到的相翻转点ASA含量为62.2 %接近。     

扩链剂对聚对苯二甲酸乙二醇酯流变性能和发泡性能影响

采用均苯四甲酸酐（PMDA）作为聚对苯二甲酸乙二醇酯(PET)的扩链剂制备了扩链改性PET（CEPET）,并以超临界二氧化碳(CO2)为物理发泡剂,采用釜压法制备了CEPET泡沫;通过旋转流变仪和扫描电子显微镜研究了CEPET的流变性能和CEPET泡沫的泡孔结构。结果表明,随着PMDA含量的增加,CEPET试样的储能模量逐渐增加,损耗因子逐渐降低,CEPET的熔体强度明显高于纯PET;CEPET泡沫的泡孔形态得到改善,发泡倍率得到提高;加入1.0 份（质量份,下同）扩链剂时,发泡倍率能够达到32.55倍。     

马来酸二丁酯固相接枝聚丙烯的流变性能研究

对聚丙烯(PP)采用先降解、后固相接枝技术,制备了具有高流动性的聚丙烯接枝马来酸二丁酯(PP-g-DBM)接枝物,并用红外光谱(FTIR)和差示扫描量热法(DSC)对接枝物结构进行了分析与表征,研究了接枝率对接枝物熔体流动速率(MFR)、分子量和流变性能的影响。结果表明:接枝改性后PP的熔点比纯PP有所下降,MFR和非牛顿指数却有所提高;随着接枝率的提高,接枝物的分子量降低,MFR提高,可达到750 g/10min,表明改性后PP的流变性能得到了明显改善。     

聚乳酸纳米复合材料流变性能研究进展

综述了各种纳米粒子,包括生物质基纳米粒子、碳基纳米粒子、纳米黏土等对聚乳酸(PLA)在剪切力场作用下的流变性能影响及其各自含量、表面处理和与PLA基体之间相互作用等对其流变性能的影响,并总结了纳米粒子对PLA流变性能的作用机理。     

芳纶1313纺丝原液的流变性能研究

研究了自制的芳纶1313纺丝溶液的浓度、温度及聚合物的相对分子质量对纺丝溶液的流动曲线、粘流活化能、非牛顿指数和结构黏度指数及松弛时间的影响。结果表明,芳纶1313纺丝溶液为切力变稀的非牛顿流体,芳纶1313聚合物相对分子质量增大、溶液浓度升高使纺丝溶液的非牛顿性增加,温度升高使其减少,其中相对分子质量的影响较其它两个因素为大。     

二异氰酸酯对聚碳酸亚丙酯熔体流变性能的影响

以4,4-二苯基甲烷二异氰酸酯（MDI）为扩链剂,在转矩流变仪上通过一步法对聚碳酸亚丙酯（PPC）进行了熔融扩链改性。结果表明,随着MDI用量的增加,扩链反应峰和平衡扭矩逐渐增大、平衡时间不断延长;红外光谱分析表明,扩链改性后的PPC在1600 、1535 cm-1处分别出现了苯环的骨架振动吸收峰和-NH的特征吸收峰;旋转流变分析表明,扩链改性后PPC的储能模量、损耗模量和复数黏度均随MDI用量的增加而增加;从Cole-Cole曲线可以看出,随着MDI用量的增加,扩链改性后PPC的相对分子质量逐渐增加,相对分子质量分布变宽,支化度提高;应力松弛测试结果表明,随着MDI用量的增加,松弛时间逐渐增加。     

尼龙11/石墨烯氧化物纳米复合材料的动态流变性能

采用原位聚合法制备了尼龙11(Nylon 11,Polyamide 11)/石墨烯氧化物(GO)纳米复合材料,并利用旋转流变仪研究了纳米复合材料的流变行为。研究结果表明:尼龙11及其复合材料均为假塑性流体,呈现切力变稀的现象;GO的加入降低了尼龙11/GO纳米复合材料的储能模量、损耗模量和复数黏度;用Cole-Cole理论检测尼龙11/GO纳米复合材料,其曲线出现双峰,表明复合材料发生相分离,与Han曲线一致。     

弱碱型三元复合驱采出水的流变性变化规律

通过旋转黏度计测试黏弹性和视黏度,研究了三元(碱、表面活性剂、聚合物)复合驱采出水的流变性。结果表明,三元复合驱采出水的黏弹性可用Maxwell线性黏弹性模型描述。其视黏度和黏弹性主要取决于所含聚合物的相对分子质量和含量,并且随聚合物含量的增加而增大。低聚合物含量三元复合驱采出水的视黏度和黏弹性模量之间存在着G=1．6736μ1.8155的关系式。     

聚丙烯/乙烯-辛烯-1共聚物共混体系流变性能研究

采用高级流变扩展系统(ARES)研究了聚丙烯(PP)/乙烯-辛烯共聚物共混体系的流变性能,探讨了乙烯-辛烯共聚物含量和 PP 种类对共混体系储能模量、剪切黏度和零切黏度的影响。实验结果显示,PP 结构和 POE 含量对 PP/POE 共混体系的剪切流变性能有显著影响,随着 POE 含量的增加,PP1/POE 共混体系的储能模量和剪切黏度增加的幅度明显小于 PP2/POE 共混体系,PP1/POE 共混体系和 PP2/POE 共混体系的储能模量和剪切黏度增加幅度较大分别发生在 POE 含量为20%～30%和10%～20%,即共混体系发生"脆—韧"转变阶段。PP/POE 共混体系中存在界面滑移现象,且 PP 和 POE 的界面相容性对界面滑移现象影响较大,其中 PP1/POE 的界面滑移比PP2/POE 的界面滑移更加明显。     

Rheological Behavior and Mechanical Properties of Blends of Poly(vinyl chloride) with CP-POSS

In this work, a polyhedral oligomeric silsesquioxane which contains 3-chloropropyl groups (CP-POSS) was synthesized. The rheological behavior of CP-POSS/PVC blends was investigated by torque rheometer and capillary rheometer. Mechanical properties were investigated by electronic material tester. Influences of blending composition, shear rate and shear stress on melt apparent viscosity and non-Newtonian index (n) were discussed. The results show that the plastic time decreases and melt viscosity increases with increasing content of CP-POSS. CP-POSS has a good compatibility with PVC. The blend has the best impact strength when the content of CP-POSS is 7 wt%. The CP-POSS can be used as a processing aid and impact-resistant aid for PVC.     

mLLDPE流变与加工特性的研究

主要研究国产mLLDPE加工特性,通过流变试验确定mLLDPE的临界剪切速率范围,并在mLLDPE中加入加工助剂,消除mLLDPE的熔体破裂现象,利用mLLDPE与LDPE共混,增强mLLDPE熔体强度,提高膜泡稳定性。     

超细AP/HTPB悬浮液的流变特性

在改进NDJ-4型旋转粘度仪的基础上。对切应力τ、切变速率γ及剪切速度指数n等流变学参数进行了估算。从填充分数、工艺助剂等方面对含硼富燃固体推进剂用超细AP／HTPB悬浮液流变特性进行了实验研究。结果表明．AP颗粒间通过粘合剂体系形成相互作用是悬浮液呈假塑性流动的主要原因．表面活性助剂(SH)可明显改善超细粒AP的表面性能。     

Effects of Surfactant Hydrophilicity on the Oil Solubilization and Rheological Behavior of a Nonionic Hexagonal Phase

The effects of surfactant hydrophilicity on the phase behavior and rheology of a hexagonal phase (H₁) and related O/H₁ emulsions in a water/C₁₂EO _n /isohexadecane system (n = 7, 9) have been investigated. In this phase behavior study, a variety of surfactant aggregates (micellar, W_m; hexagonal, H₁; bicontinuous cubic, V₁; lamellar, L_α; inverse micellar, O_m) have been observed in water-C₁₂EO _n binary systems. The oil solubility of different surfactant aggregates was strongly affected by the surfactant hydrophilicity, i.e., surfactant aggregates in the C₁₂EO₇ system could solubilize a larger amount of oil than those in the C₁₂EO₉ system. It can be inferred that the surfactant with long hydrophilic head groups could be closely packed in the interface, leading to a reduction in the oil solubility in the micellar core due to the strong head group interaction. Interestingly, the rheology of the H₁ phase also exhibits behavior that is dependent on the surfactant hydrophilicity, i.e., high values of the elastic modulus G′ and complex viscosity |η*| have been observed in the C₁₂EO₉ system, possibly due to the strong neighboring head group interaction. Hexagon structure of the H₁ phase was calculated by using the Bohlin model. The viscosity of the O/H₁ emulsions decreases with increasing oil concentration, possibly due to the low volume fraction of the continuous phase (the H₁ phase).     

熔融缩聚法合成的聚乳酸熔体的流变性能研究

采用锥板流变仪研究聚L-乳酸(PLLA)的流变性能,并对直接法熔融缩聚制备的聚乳酸进行了测试。结果表明:PLLA熔体属于切力变稀流体;PLLA熔体的表观粘流活化能较高,其表观黏度对温度的敏感性高。