UHMWPE/HDPE共混体系的流动性和力学性能研究

将一定量超高分子量聚乙烯(UHMWPE)引入高密度聚乙烯(HDPE)中构成共混体系,通过对共混体系的熔体质量流动速率(MFR)、拉伸屈服强度、弯曲性能、冲击强度进行研究,探讨了不同质量分数、不同相对分子质量的UHMWPE对UHMWPE/HDPE共混体系的流动性和力学性能的影响。     

低分子量乙丙共聚物对聚乙烯/聚丙烯共混体系流变性能的影响规律

研究了低分子量乙丙共聚物(LMW-EP)对聚丙烯/聚乙烯(PP/PE)共混体系转矩流变以及动态流变性能的影响.并采用Cole-Cole Plot作图法计算共混物黏弹性参数.结果表明:LMW-EP的加入有效改善了PP/PE共混体系的流动性,为聚乙烯/聚丙烯共混体系的发泡稳定性提供帮助.     

聚乙烯/石蜡油共混体系动态流变行为和相容性

将分子量相差较大的两种聚乙烯(PE)分别与石蜡油(LP)组成共混体系,通过旋转流变仪、偏光显微镜(PLM)、差示扫描量热仪(DSC)和扫描电子显微镜(SEM)研究了温度和LP含量对共混体系动态流变行为的影响,并对两相共混体系的相容性及微孔结构进行了表征.结果表明,随着温度的升高和LP含量的增加,PE/LP共混体系的储能...     

PE分子量对硬PVC／CPE／PE共混体系性能的影响

研究表明，ＰＥ分子量对硬ＰＶＣ／ＣＰＥ／ＰＥ共混体系的力学性能有重要影响，在实验配方范围内，以超高分子量聚乙烯（ＵＨＭＷＰＥ）对体系的增韧增强改性效果为佳，但应切实注意ＵＨＭＷＰＥ的流动性与分散性，适当减少ＵＨＭＷＰＥ用量和以普通聚乙烯对其增塑改性均能达到良好效果。     

茂金属聚乙烯蜡对PE共混体系流变行为的影响

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。     

几种不同结构型号PE改性PPR力学性能的研究

研究了线性低密度聚乙烯(LLDPE)/聚丙烯(PPR)共混体系、高密度聚乙烯(HDPE)/聚丙烯(PPR)共混体系、超高分子量聚乙烯(UHMWPE)/聚丙烯(PPR)共混体系的力学性能和熔体流动速率。结果表明,UHMWPE的增韧改性效果最好,在UHMWPE的含量为15%时体系的综合力学性能最好。LLDPE的增韧改性效果次之,HDPE的最差。     

ADR对PLA/PE-g-MA共混体系结构与性能影响

在聚乳酸/马来酸酐接枝聚乙烯(PLA/PE-g-MA)体系中添加环氧扩链剂ADR进行熔融共混,研究了ADR含量对PLA/PE-g-MA共混体系的熔体扭矩、分子量、微观形貌和力学性能的影响。结果表明:ADR对PLA/PE-g-MA体系具有反应性增容作用,有效改善了体系的界面相容性,使分散相粒径显著减小,材料的韧性明显提高,其断裂伸长率最高可达320%。     

振动外场对LLDPE/UHMWPE纤维共混体系结晶行为的影响

主要研究了在不同温度下,振动外场对线型低密度聚乙烯(LLDPE)/超高分子量聚乙烯(UHMWPE)纤维共混体系结晶行为的影响。扫描电镜(SEM)分析结果表明,在125℃或150℃下施加振动后,LLDPE/UHMWPE纤维共混体系都形成了串晶结构,而升高温度不利于串晶结构的形成。差示扫描量热分析(DSC)的结果也表明,施加振动后共混体系出现了特殊晶体。广角X射线衍射分析(WAXD)的结果表明,施加振动后共混体系的取向度得到了提高。力学性能测试结果表明,施加振动后共混体系的拉伸强度有所提升。     

一种共混超高分子量聚乙烯的纺丝方法

正本发明一种共混超高分子量聚乙烯的熔融纺丝方法,包括如下步骤:将UHMWPE与HDPE充分均匀混合,然后进行熔融纺丝,熔融纺丝后进行后牵伸,得到聚乙烯纤维。本发明的共混超高分子量聚乙烯的熔融纺丝方法是将一定比例的超高分子量聚乙烯和高密度聚乙烯充分混合,加入高密度聚乙烯后可以提高超     

小本体聚丙烯增韧研究

采用机械共混方法对小本体聚丙烯进行了增韧改性研究,探讨了增韧剂种类、含量以及有少量聚乙烯存在下对聚丙烯共混体系力学性能的影响,并与连续法聚丙烯进行了比较。实验结果表明,聚丙烯/增韧剂/聚乙烯三元共混体系可以获得理想的增韧效果。     

Rheological properties of cellulose/chitin xanthate blend solutions and properties of the prepared fibers

The focus of this article is the rheological properties of cellulose xanthate, chitin xanthate, and their blend solutions with cellulose/chitin blend weight ratios of 9.5 : 0.5, 9 : 1, 8 : 2, and 5 : 5 (mostly 9 : 1 blend solutions). The preparation and properties of fibers from 9 : 1 blend solutions and cellulose xanthate solutions are also discussed. The non‐Newtonian index of the investigated solutions was found to vary in the following order: chitin < cellulose < 9.5 : 0.5 blend < 9 : 1 blend < 8 : 2 blend < 5 : 5 blend. Showing a tendency contrary to that of the non‐Newtonian index, the structure viscosity index varies in the following order: chitin > cellulose > 9.5 : 0.5 blend > 9 : 1 blend > 8 : 2 blend > 5 : 5 blend. For 5–9 wt % 9 : 1 blend solutions, increasing the solution temperature aids the improvement of the fluidity of 9 : 1 blend solutions in the temperature range of 10–40°C. The zero shear viscosity decreases in an index manner with the solution temperature increasing. The 7–8 wt % 9 : 1 blend solutions have good filtering and rheological properties and are ideal for spinning fibers. The mechanical properties of blend fibers spun from 7% 9 : 1 blend solutions are lower than those of pure cellulose and are much higher than those of Crabyon fiber, and they still reach the national criteria and fit the need for further processing. This proves that the viscose method which we have developed here is an efficient way of preparing cellulose/chitin blend fibers with satisfactory mechanical properties and processing properties. Scanning electron microscopy photographs show that the surface of 9 : 1 blend fibers is coarser than that of pure cellulose fibers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

聚合物共混物相容性评价的研究进展

分别介绍了评价非晶／非晶聚合物共混物、结晶／非晶聚合物共混物、结晶／结晶聚合物共混物相容性的方法及研究进展，并对聚合物共混物相容性的评价方法作了简要的讨论。     

阴离子/非离子表面活性剂协同效应研究

研究了脂肪酸甲酯磺酸钠(MES)与脂肪醇聚氧乙烯醚(AEO9)复配体系在298 K、318 K下的表面化学性质,计算了二者在混合胶束及混合吸附层中的协同作用参数,进而得知混合胶束及混合吸附层中二者的组成情况。结果显示,复配体系的表面化学性能明显优于单一体系,复配体系无论在混合吸附层或混合胶束中均显示出强烈的协同作用。     

Inventory pinch algorithm for gasoline blend planning

Current gasoline blend scheduling practice is to optimize blend plans via fixed duration (e.g., days) multiperiod NLP or MINLP models and schedule blends via interactive simulation. Solutions of multiperiod models typically have different blend recipes for each time period. We introduce inventory pinch points and use them to construct an algorithm based on single‐period nonlinear model to minimize the number of different blend recipes. The algorithm optimizes multigrade blend recipes for each period delimited by the inventory pinch points and then uses a fine‐grid multiperiod fixed‐recipe MILP to compute blend volumes profile. If MILP is infeasible, a corresponding period between the pinch points is subdivided and recipes are reoptimized. In our case studies, solutions are computed in significant less time and are most often within 0.01% of the solutions by multiperiod MINLP. Reduced number of blend recipes makes it easier for the blend scheduler to create a schedule by interactive simulation. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3748–3766, 2013     

聚碳酸酯—聚苯乙烯的反应性挤出共混研究（Ⅱ）

用ＤＳＣ进一步研究了ＰＣ／ＰＳ共混物的相容性。考察了在ＰＣ／ＰＳ混合过程中加入ＲＰＳ对机械力学性能的影响,结果表明：ＲＰＳ显示良好的增容作用,使反应性挤出共混物的拉伸强度,弯曲强度和冲击强度都高于相应的非反应性共混物。     

Chemical crosslinking of hydroxypropyl cellulose and chitosan blends

Two liquid crystal forming polysaccharides, hydroxypropyl cellulose and chitosan, were blended in aqueous acetic acid solutions and were crosslinked with dialdehydes (glyoxal and glutaraldehyde) as crosslinker and hydrochloric acid as catalyzer. The crosslinkability, morphology, solubility, and tensile properties of the cross linked blend films are determined and the dependence of those properties on the blend composition and on crosslinker species are discussed. The crosslinked blend films cast from the aqueous acetic acid solutions were amorphous. The solubility, Young's modulus, and tensile strength of the crosslinked blend films greatly depended on blend composition; those properties appeared to exhibit a maximum and a minimum around given blend compositions. The solubility for the crosslinked blend film cast from glyoxal system was greater than that from glutaraldehyde one. © 1996 John Wiley & Sons, Inc.     

共混超滤膜的研究进展

本文综述了共混超滤膜的发展现状、工艺条件与膜性能的关系 ,并阐述了共混超滤膜的优点     

聚酰胺增韧改性研究进展

介绍4类增韧尼龙合金,即聚烯烃、烯烃共聚物、弹性体共混;掺混高性能工程塑料;无机非弹性体增韧和各种尼龙共混材料。对影响增韧改性的各种因素进行了讨论,列举了主要研制工作概况。     

新型多单体接枝物增容PP/PVC共混体系的研究

自制了多单体接枝物PP g (St co MMA) ,并利用其增容PP/PVC共混体系。讨论了共混物组成、相容剂用量在不同温度、不同压力下对其流变行为的影响。实验结果表明 ,在所研究的温度和压力范围内 ,加入PP g (St co MMA)增容PP/PVC共混体系后 ,共混物熔体呈典型的假塑性流体特性 ,粘流活化能增加 ,非牛顿性有增大的趋势。共混体系的力学性能提高 ,SEM照片证明了多单体接枝物对PP/PVC的增容作用     

Crystallization,tensile, and impact behavior of polypropylene/polybutadiene blend

A blend of isotactic polypropylene (PP) and polybutadiene (PBu), in the composition range 5–35 wt % PBu content, prepared by mixing in a two-roll mill, is studied for crystallization, tensile, and impact behavior. Variations in crystallization behavior and the resulting morphology and structure are observed in both differential scanning calorimetry (DSC) and X-ray diffraction measurements on this blend as a function of blend composition. Impact and tensile properties are studied in the entire blend composition range. Analysis of tensile properties data in terms of the various theoretical models is attempted to obtain better insight into the interphase adhesion and stress concentration effect in this blend. The effects of blend composition on the state of dispersion and morphology of dispersed phase droplets and correlation of tensile properties with the crystallization parameters of PP component are also presented.