含氟共聚芳醚酮的合成与性能研究

通过三步反应合成新的含氟双酚单体4-氟苯基对苯二酚,在该含氟双酚单体中加入不同比例的间苯二酚与4,4'-二氟二苯酮经亲核缩聚反应制备了一系列新型共聚芳醚酮.用傅立叶变换红外光谱仪、差示扫描量热仪、热失重分析仪及广角X射线衍射仪等对聚合物的结构和性能进行了表征和研究.结果表明,该共聚物为非晶态,具有优异的耐热性能,其玻璃化转变温度(Tg)在123～159℃、氮气中5%热失重温度在510℃以上;且具有良好的溶解性,室温下能溶解于N-甲基吡咯烷酮、N,N-二甲基乙酰胺、氯仿等有机溶剂.     

含氟聚合物/多壁碳纳米管复合材料的导热性能

为提高含氟聚合物F2314的导热性能,采用多壁碳纳米管(MWCNTs)对F2314进行改性。用密炼混合法制备了F2314/MWCNTs复合材料。研究了MWCNTs含量、温度对F2314/MWCNTs复合材料的导热系数的影响。建立了F2314/MWCNTs复合材料的导热模型。结果表明,F2314/MWCNTs复合材料的导热系数随MWCNTs含量增加而增大。当MWCNTs质量分数为30%时,30℃下F2314/MWCNTs复合材料的导热系数高达0.647 W·m~(-1)·K~(-1),比纯F2314的导热系数提高3.43倍。F2314/MWCNTs复合材料的导热性能对温度的依赖性与F2314的相态转变密切相关。随着温度增加,F2314/MWCNTs复合材料的导热系数先增加,然后在玻璃化转变温度附近达到最大值,接着逐渐降低。有效介质方法修正公式的计算结果与实验吻合较好,表明该公式可以较好地模拟F2314/MWCNTs复合材料的导热性能。     

DMA方法研究多壁碳纳米管/F2314复合材料的粘弹性能

用熔融共混法制备了多壁碳纳米管(MWCNTs)/氟聚物(F2314)复合材料。用动态机械热分析(DMA)法考察了MWCNTs含量对复合材料粘弹性能(动态力学行为和三点弯曲蠕变性能)的影响。结果表明,随着MWCNTs含量的增加,MWCNTs/F2314复合材料的储能模量增加,玻璃化转变温度和损耗因子峰值(tanδmax)减小。MWCNTs的存在使得MWCNTs/F2314复合材料的蠕变应变和稳态蠕变速率减小。80℃/0.1 MPa下,当MWCNTs含量从2%增加到20%时,MWCNTs/F2314复合材料的蠕变应变和稳态蠕变速率分别减小87.6%和84.7%。Burger四元件模型可以模拟MWCNTs/F2314复合材料的蠕变行为,并获得蠕变曲线的本构方程。     

A statistical study on selected process parameters of electrospraying

Deposition time is a key factor in determining application ease, time, and cost of electrospraying. This statistical study investigates the contribution of process parameters of electrospraying on deposition time when conducted for the application of commercially available fluoropolymer resin onto cotton fabric. The results showed that solution viscosity was highly significant on deposition time, and any variation in other parameters would cause highly significant changes in deposition time for the solutions with a higher viscosity/fluoropolymer resin concentration.     

A study on thermal behavior of a poly(VDF‐CTFE) copolymers binder for high energy materials

This article describes a study on thermal behavior of poly(vinylidene fluoride‐chlorotrifluoroetheylene) [poly(VDF‐CTFE)] copolymers as polymeric binders of specific interest for high energy materials (HEMs) composites by thermal analytical techniques. The non‐isothermal thermogravimetry (TG) for poly (VDF‐CTFE) copolymers was recorded in air and N₂ atmospheres. The results of TG thermograms show that poly(VDF‐CTFE) copolymers get degrade at lower temperature when in air than in N₂ atmosphere. In the derivative curve, there was single maximum degradation peak (T_max) indicating one‐stage degradation of poly(VDF‐CTFE) copolymers for all the samples. The other thermal properties such as glass transition temperature (T_g) and degradation temperature (T_d) for poly(VDF‐CTFE) copolymers were measured by employing differential scanning calorimeter (DSC) technique. The kinetic parameters related to thermal degradation of poly(VDF‐CTFE) copolymers were investigated through non‐isothermal Kissinger kinetic method using DSC method. The activation energies for thermal degradation of poly(VDF‐CTFE) copolymers were found in a range of 218–278 kJ/mol. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

氟塑料物理发泡绝缘微同轴电缆的研制

论述了氟塑料——聚全氟乙丙烯(FEP)物理发泡绝缘微同轴电缆的设计依据、结构设计要点、主要材料的性能、制造工艺要点及研制样品的工艺结构和性能。     

涂料用含氟聚合物乳液的合成与性能

含氟聚合物乳液因具有优异的表面特性、耐候性和环境友好性,在高耐候涂料和特殊性能涂料领域获得广泛的应用。本文综述了含氟聚合物乳液的制备用单体、乳化剂及制备方法。论述了含氟聚合物乳液涂料的结构与性能的关系,指出了含氟聚合物乳液的研究工作的重点。     

Sorption/desorption and diffusion kinetics of ketones and nitriles into fluoropolymer membranes

Analysis of sorption/desorption and diffusion kinetics of ketones and nitriles at 25, 44, and 60°C into three Du Pont's VITON fluoropolymer membranes loaded with different amounts of carbon black has been undertaken by use of a sorption/desorption technique. The transport results are affected by the percent loading of carbon blacks. Diffusion coefficients have been calculated from Fick's equation. These results show a decrease with increasing amount of carbon black. Experimental results have been analyzed by considering swelling of the membranes. Sorption/desorption results have been analyzed from a calculation of the concentration profiles, which are obtained from the analytical solution of Fick's equation. These results have been compared with a numerical solution based on the finite difference method. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 635–647, 1997     

含氟流变剂在聚烯烃加工中的应用

熔体破裂是高粘度、高分子量聚烯烃挤出成型中遇到的最严重的问题。利用国产氟聚合物自制含氟流变剂微粉,分别用于高粘度LLDPE、高分子量HDPD、PP树脂挤出成型,进行流变性能分析,结果表明:在聚烯烃挤出成型过程中加入含氟流变剂可有效消除熔体破裂现象,降低熔体温度,减小挤出机头压力,提高挤出效率。     

Core–shell latex containing fluorinated polymer rich in shell

Core–shell latex with polyacrylate rich in core and fluoropolymer rich in shell was prepared by semicontinuous emulsion polymerization in the presence of mixed emulsifiers. The solids content of the latex was about 25 wt %. The polymerization conditions for the latex were discussed. The morphology of latex particles was characterized by transmission electron microscopy and the surface properties were determined by the Wilhelmy method. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1147–1153, 2002