ELECTRON BEAM PRE-RADIATION-INDUCED GRAFT POLYMERIZATION WITH UHMWPE FIBERS

In order to improve the surface adhesion of high strength and high modulus poluethylene (PE)fibers with epoxy resin,graft polymerization of some monomers by electron beam(EB)pre-radia-tion was performed on the surtacc of PE fibers.In the paper,the Van de Graft accelerator waschosen as a radiation resource.And we found from our studies that no sensitizer was needed in EBpre-radiation polymerization under the atmosphere of N_2,and acrylic acid was most effective inthe polymerization of methyl methacrylate,acrylic acid and methacrylic acid.The degree of graftincreased with the enhancing of pre-radiation dose,reaction temperature and reaction time.Acetone and benzene were effective solvents for acrylic acid.Oligomer which exists during thepolymerization could be removed by washing with benzene.Grafted fiber was analyzed by SEMand ATR-IR and it was confirmed that some polar groups were introduced to the surface of PE fi-ber.The tensile strength of PE fibers did not decrease greatly when pre-radiation dose was lessthan 1.56×10~4 Gy.     

The Flow Behavior of Poly（m-Phenyleneisophthalamide） Concentrated Solution

IntroductionPoly(m-phenyleneisophthalamide)(PMIA)fibers arei mportant materials with excellent ther mal and oxidativestability,flame resistance,and dielectric properties.Thedecomposition temperature of PMIA is400430℃andeven under this temperature it releases little har mful gases.Unlike flame-retardant treated materials,PMIAfibers areinherently flame resistance and it will not di minish duringthe life of the fiber.The fiber s low tenacity and highelongation give it textile-like character…     

低温溶液缩聚法制备间位芳香族聚酰胺的研究

采用低温溶液缩聚的方法将间苯二胺(MPD)和间苯二甲酰氯(IPC)在N，N’-二甲基乙酰胺(DMAC)中进行缩聚，制得了较高重均相对分子质量的间住芳香族聚酰胺树脂。研究了聚合度与反应时间的关系，并对影响缩聚的各种因素如：单体浓度、起始反应温度、两种单体的摩尔比进行了研究，还对制得的浆液的稳定性进行了观察。     

涤纶改性共混体系--PMMA/PET 结晶性能的研究

采用DSC研究了PMMA／PET共混体系的非等温熔融结晶行为。结果表明：在PMMA／PET共混体系中，当PMMA的质量分数为1．0％－7．5％时，PMMA的加入提高了PET的结晶能力，其中质量分数为1％时最甚。共混体系的m值大于PET，故PMMA的加入不起成核剂的作用， 只是促进晶核的生长。     

静电纺丝聚丙烯腈纳米纤维工艺参数与纤维直径关系的研究

采用静电纺丝方法来纺制聚丙烯腈（PAN）纳米纤维毡研究了质量分数、电压、针孔孔径、纺丝液中LCl的含量、接受距离等参数对纤维直径及离散度的影响，采用扫描电镜来观察纤维的直径及其形态。采用正交试验设计法，发现纺丝液的质量分数与纺丝液中LiCl的含量是影响纤维直径最重要的参数。经过优化，纺制出最小直径为98nm的纳米纤维。     

UHMW-PE 冻胶丝的萃取机理及萃取剂的选择

超高分子量聚乙烯(UHMW—PE)冻胶丝的萃取不同于一般化学概念上的萃取.本文采用气相色谱分析法证实了它是一个动态平衡过程.冻胶丝的萃取过程包括了溶剂与萃取剂的相互渗透、相互替代和挥发干燥.冻胶丝萃取剂根据溶剂种类不同而有多种,萃取效果可采用平衡萃取时间(T_(BE))、平衡挥发时间(T_(VE))和平衡干燥收缩率(S_(RE)%)等宏观指标来衡量。由此为萃取剂的选择提供了理论依据.     

预氧化腈纶短纤维的耐酸碱性

本文通过广角 X 射线衍射、纤维力学性能的测定、扫描电镜方法等研究了在不同浓度硫酸及氢氧化钠水溶液、不同处理温度和不同时间条件下,具有不同预氧化程度的预氧化腈纶短纤维耐酸碱的基本行为。探讨了预氧化腈纶短纤维在酸碱水溶液作用下,力学性能下降的机理及纤维预氧化程度对耐酸碱性的影响。     

用均匀设计对PPTA纺丝工艺进行优化

在聚对苯二甲酰对苯二胺(PPTA)纤维纺丝工艺初步成形的基础上,利用均匀设计法建立回归模型.以纤维断裂强度作为质量指标,对PPTA纺丝过程中的喷出速度、拉伸倍数、卷绕速度3个主要工艺参数进行了优化,力图用最少的试验次数确定最佳的工艺条件.通过计算得到回归方程,经过残差分析可知该方程的可靠性较高.利用SUMT外点法寻优,计算得到PPTA纺丝的最佳工艺条件:喷出速度为26.68m/min,拉伸倍数为7.76倍,卷绕速度为208.34m/min,则PPTA纤维的理论断裂强度为35.67cN/dtex.     

含铜聚丙烯腈导电纤维导电化处理过程的动力学研究

通过原子吸收分光光度计对含铜聚丙烯腈导电纤维制备过程中的动力学进行了研究，结果表明在处理过程中，铜盐和还原剂之间发生的是二级反应，反应的阿伦尼乌斯活化能为60．520kJ.mol^-1，在酸性介质中，反应速率减慢，其阿伦尼乌斯活化能降为27．618kJ.mol^-1。同时，随着pH的降低，温度对反应速率的影响降低，纤维上导电结晶层更趋于均匀。     

Preparation of Silk-Like PET Microfilament and Its Properties

The polyester microfilament was prepared by means ofnormal fully drawn yarn(FDY)equipment.The effectof water content in chips,the molecular weight of thechips,the jet stretch ratio and the lateral blow on thespinnability and the finest titre of filament that could bereach were discussed.Under convenient conditions,thefiber with linear density of about 1.4 dtex could be ob-tained.By means of wide angle X-ray diffractometer(WAXD),differential scanning calorimeter(DSC)andInstrontester,the structure and properties of the mi-crofilament were discussed.