导电聚苯胺/聚乙烯醇复合乳液的制备研究

以聚乙烯醇为树脂基体 ,通过乳液氧化聚合同步搀杂有机酸 ,研究了聚苯胺 /聚乙烯醇复合乳液的制备。结果表明 ,过硫酸铵的用量对聚苯胺的产率影响较大 ,当氧化剂 /苯胺的摩尔比达到 2时 ,产率为95% ,高于溶液法的原料比例。十二烷基苯磺酸和聚乙烯醇 (88%醇解度 )对聚苯胺乳胶的粒径亦有影响。在聚苯胺 /聚乙烯醇复合膜中 ,当聚苯胺含量超过 2 0 %后 ,电导率趋向稳定 ,可达 2 .3 s/ cm     

聚苯胺导电涂料的制备及性能研究

本研究采用氧化聚合方法制备了具有高电导率的导电聚苯胺。并以这种聚苯胺为导电填料,以丙稀酸为成膜物,制备了一种电导率为10-8～10-5s/m的导电涂料。并研究了聚苯胺含量对导电涂料电导率及涂膜性能的影响。     

几种酸掺杂聚苯胺-聚乙烯醇复合导电涂料的制备

采用聚乙烯醇为基质材料,以盐酸、十二烷基苯磺酸、氨基磺酸水溶液掺杂,制备了聚苯胺-聚乙烯醇(PANI-PVA)复合导电涂料。研究了PANI与PVA质量比、酸用量、氧化剂用量、反应时间以及膜干燥温度等因素对涂料膜电导率的影响。结果表明:当PVA质量分数为40%、成膜干燥温度为80℃时,PANI-PVA涂料膜的电导率最大。而且当cHCl=0.5mol/L、反应时间为6h、过硫酸铵与苯胺摩尔比为1.0时,所得HCl-PANI-PVA膜的电导率达最大,为15.0S/cm;当cDBSA=1.0mol/L、反应时间为8h、过硫酸铵与苯胺摩尔比为2.0时,所得DBSA-PANI-PVA膜的电导率达最大,为7.1S/cm;当cNH2SO3H=1.0mol/L、反应时间为6h、过硫酸铵与苯胺摩尔比为2.0时,所得NH2SO3H-PANI-PVA膜的电导率达最大,为2.0S/cm。在这几种酸掺杂的PANI-PVA复合导电涂料中,HCl-PANI-PVA膜的电导率最大。     

聚苯胺防腐导电涂料的制备研究

采用氧化缩聚合成法制备了无机峻掺杂的低成本、高导电率的导电聚苯胺，以其为导电填料，以环氧树脂为成膜物，制备出一种电导率在10^-8～10^-5S／m范围内的新型导电涂料。研究了聚苯胺含量对涂膜的电导率、物理性能以及耐化学品性的影响，同时采用交流阻抗曲线探讨了涂料对金属基材的防腐蚀行为。     

导电聚苯胺复合膜的研制

以聚甲基丙烯酸甲酯(PMMA)为基质,过硫酸铵为氧化剂,十二烷基苯磺酸为掺杂剂,进行苯胺的原位氧化聚合,制备聚苯胺(PAn)／PMMA复合材料,采用溶液浇铸法制成了性能优良的可溶性导电复合膜,电导率达10^-2S／cm;考察了反应条件对复合膜电导率的影响,并进行了环境稳定性测试,用红外光谱进行了复合膜的结构表征,用元素分析法测定了复合膜的组成,结果表明复合的聚苯胺存在—饱和值,超过饱和值,对电导率影响不大。     

掺杂型聚苯胺导电涂料的研究

研制了一种以环氧树脂为基料,掺杂型聚苯胺为导电填料的导电涂料。研究了导电涂料中掺杂型聚苯胺以及聚酰胺类固化剂对导电涂料性能的影响,并对导电涂料的电阻率、柔韧性及附着力等性能进行了测试。结果表明,该涂料ρ为20~25Ω.cm,具有优良的导电性,且涂膜的柔韧性达到1.0mm。     

新型聚苯胺系防腐蚀导电涂料的制备与研究

用化学氧化聚合方法（辅以超声分散技术）合成了具有纳米尺寸的聚苯胺,以其为导电填料,以丙烯酸酯为成膜物,制备出一种电导率在18～10^4S／m范围内的新型防腐导电涂料。讨论了聚苯胺含量对涂膜的电导率、外观、硬度、冲击力、附着力以及耐化学试剂性的影响,同时采用交流阻抗、电化学极化曲线研究了涂有该涂料的电极的电化学行为。结果表明,当聚苯胺质量分数在15％～30％范围时,涂膜具有良好的导电性、光泽以及耐化学试剂性,抗冲击强度为50kg／cm^2,附着力为1～2级,硬度为3日～1HB,Tafel曲线及EIS研究进一步表明该导电涂料有良好的抗腐蚀性。     

聚苯胺/PA11共混导电纤维的研制Ⅱ.影响纤维导电性能的因素

讨论了对采用湿法纺丝工艺纺制的聚苯胺/ＰＡ１１纤维的导电性能的一些影响因素,研究表明聚苯胺在纤维中的含量和处理纤维的酸度对纤维的导电性能有较大的影响,增加纤维后拉伸倍数可在一定程度上提高纤维的导电性能,测试电压和施加电场的时间对纤维的导电性能也有一定的影响。     

PANI-DBSA/MMA-BA共聚物导电涂料的结构与性能表征

以十二烷基苯磺酸(DBSA)掺杂的聚苯胺(PANI)为导电组分,三氯甲烷为溶剂,采用溶液共混法制备聚苯胺/丙烯酸酯共聚物(AA)导电薄膜。对导电薄膜进行了导电性能测试,扫描电镜(SEM)、红外光谱(FT-IR)及差示扫描量热(DSC)分析。结果表明:导电薄膜的电导率随PANI-DBSA含量的增加而增加,体系的逾渗阈值低于4%(质量分数)。共混体系表现出良好的相容性。     

关于导电涂料导电性能的讨论

讨论了各种因素，包括填料、溶剂、成膜物质、固化条件及外加磁场等对导电涂料导电性能的影响，表明各种因素的作用实质都在于改变了填料粒子的接触数目和彼此间的距离。通过这些因素的调整可以改进涂料的性能。     

聚乙烯醇硫酸钾（PVSK）的制备及其结构分析

研制了胶体滴定法所需的标准阴离子型聚电解质试剂ＰＶＳＫ，探讨了合成条件的影响，并对ＰＶＳＫ的结构进行了分析。为阳离子聚电解质测试中应用胶体滴定法提供了物质条件。     

PREPARATION OF A NOVEL SEMI-INTERPENETRATING POLYMER NETWORK (IPN) AND STUDY OF THE RELEASE DYNAMICS OF HUMAN BLOOD THROUGH THE IPN

A novel interpenetrating polymer network (IPN) of poly (ethylene glycol), poly(vinyl alcohol) and poly(acrylamide) was prepared and its potential for sorption and delivery of human blood was evaluated. The influence of chemical composition of the IPN on the release dynamics of blood was also investigated. On the basis of the Fick's equation the diffusional exponent (n) was evaluated for different IPN compositions and tentative mechanisms of blood transport were worked out. Effect of pH of the release medium on the released amount of blood was also studied.     

以羧基改性聚乙烯醇为乳化剂的醋酸乙烯乳液聚合及聚合物的乳液性能研究

以羧基改性的聚乙烯醇高分子表面活性剂(m-PVA)为乳化剂,进行醋酸乙烯(VAC)乳液聚合,研究了 m-PVA 的用量和醇解度,引发剂的用量和加入方式对聚合速率的影响。同时还研究了乳液的流变特性和稳定性,并与以常用 PVA1788和1799为乳化剂的乳液性能进行了比较。发现,以 m-PVA 为 VAC 乳液聚合的乳化剂,可制得高粘度低固含量、触变性和稳定性良好的聚醋酸乙烯(PVAC)乳液。     

Drug release behavior of electrical responsive poly(vinyl alcohol)/poly(acrylic acid) IPN hydrogels under an electric stimulus

The electrically modulated properties of interpenetrating polymer networks (IPN) composed of poly(vinyl alcohol) (PVA) and poly(acrylic acid) (PAAc) under electric field were investigated for drug delivery systems. PVA/PAAc IPNs with various compositions were synthesized by a sequential method, that is, ultraviolet polymerization of AAc in the mixture of PVA and aqueous AAc monomer solution, followed by a freeze‐thawing process to prepare elastic hydrogels. The amount of loaded drug significantly increased with the content of PAAc containing ionizable groups in IPN. The amount of introduced ionic drug (cefazoline) was greater than that of the nonionic drug (theophylline). Release behaviors of drug molecules from negatively charged PVA/PAAc IPN were switched on and off in a pulsatile pattern depending on the applied electric stimulus. The released amount and the release rate of drug were influenced significantly by the applied voltage, ionic group contents in IPN, ionic properties of drug solute, and the ionic strength of release medium. In addition, the ionic properties of drug molecules dramatically affected release behaviors, thus the release of ionic drug was much more enhanced than that of the nonionic drug. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1752–1761, 1999     

醋酸乙烯和聚乙烯醇产品需求预测

详细介绍和分析了醋酸乙烯和聚乙烯醇的用途及国内外市场需求，生产装置和生产能力的变化趋势。     

Thermal characteristics of poly(vinyl alcohol) and poly(vinylpyrrolidone) IPNs

Interpenetrating polymer network (IPN) hydrogels based on poly(vinyl alcohol) (PVA) and 1‐vinyl‐2‐pyrrolidone (VP) were prepared by radical polymerization using 2,2‐dimethyl‐2‐phenylacetophenone (DMPAP) and methylene bisacrylicamide (MBAAm) as initiator and crosslinker, respectively. The thermal characterization of the IPNs was investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and dielectric analysis (DEA). Depressions of the melting temperatures of PVA segments in IPNs were observed with increasing VP content via the DSC. The DEA was employed to ascertain the glass transition temperature (T_g) of IPNs. From the result of DEA, IPNs exhibited two T_gs indicating the presence of phase separation in the IPN. The thermal decomposition of IPNs was investigated using TGA and appeared at near 270°C. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1844–1847, 2002     

Properties of branched and network poly(vinyl alcohols) prepared with poly(vinyl alcohol) having aldehyde groups at the chain ends

Branched and network poly(vinyl alcohols) (PVAs) were prepared with inter-acetalization of the PVA with aldehyde groups at the chain ends which was prepared by the cleavage of 1,2 glycol bonds in commercial PVA. The numbers of branches estimated from molecular weights were compared with those estimated by theory. Huggins' constant and crystallinity decreased with increasing branch number. Dissolution of branched PVAs into dimethylsulphoxide was not so easy compared with commercial PVA. The colour of branched PVA–iodine complex decreased rapidly with standing while that of commercial PVA decreased gradually. Network PVAs with Young's modulus of 1–8 MPa were prepared.     

The influence of poly(vinyl alcohol) suspending agents on suspension poly(vinyl chloride) morphology

The requirements for PVC suspension resin have changed considerably in the last few years, so much so that few companies have products on their ranges that are more than 4 or 5 years old. The suspending agent has a crucial influence on the morphology of the resin, so the changes in resin characteristics have largely been achieved by changes in the suspending agent systems. After a brief review of the mechanism of PVC suspension polymerisation, the properties of polymers made using PVOH suspending agents are related to changes in the latter. The effect of variations in PVAc degree of hydrolysis and viscosity are related to changes in surface tension. Methods of achieving higher porosity by using low hydrolysis co-suspending agents are described. It is shown that higher bulk densities can be achieved by delayed addition of the PVOH. Levels of conjugated unsaturation and copolymer distributions are also shown to have important influences.     

PP涂复专用料的研制及其应用

通过对国产涂复组PP、通用级PP与LDPE共混,专用料的分子量及其分布()、粘均分于量、熔体流动速率(MFR)、零切粘度(η_0)等参数的理论分析,结果表明;PP的MFR相同,但因值的差别,使它们的η_0、、加工条件及涂复膜的性能都会有明显的差异;根据PP降解机理,研制了类似母料形式的PP涂复专用料;其涂复制品主要性能超过GB 8947—88标准。     

Cellular PVA hydrogels produced by freeze/thawing

Cellular poly(vinyl alcohol) (PVA) hydrogels that exhibit enhanced swelling kinetics from an initial dry state were prepared by freezing and thawing techniques in the presence of NaCl. Gels that were dried immediately after preparation demonstrated a dual‐sorption effect upon swelling. Gels that were exposed to a 10‐day washing period to remove NaCl and excess PVA chains before drying showed an increased initial rate of swelling and overall water content. Freeze/thawed, cellular PVA gels showed overall enhanced swelling with increased mechanical strength over traditional gels prepared by chemical or irradiative crosslinking techniques. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 2075–2079, 2000