原位聚合法制备PANI/RGO导电复合材料的性能

采用原位聚合法制备聚苯胺(PANI)、PANI/氧化石墨烯(GO)复合材料和PANI/还原氧化石墨烯(RGO)复合材料。利用四探针测试仪、X射线衍射(XRD)仪、傅立叶变换红外光谱(FTIR)仪、热重(TG)分析仪和扫描电子显微镜(SEM)等对PANI及PANI/GO复合材料和PANI/RGO复合材料进行表征。电导率测试结果表明,当加入GO质量分数为50%时,先还原后聚合法制得PANI/RGO复合材料的导电率可达9.916 S/cm,RGO能有效提高复合材料的导电性;XRD和FTIR分析结果表明,GO和RGO都能较好分散在PANI中;TG分析结果表明,将GO还原为RGO后在小于250℃时能有效提高复合材料的热稳定性。通过原位聚合法能将GO和RGO较好分散在PANI中,形成较好的插层型复合材料,尤其是先还原后聚合法制得的PANI/RGO复合材料具有较好的导电性和热稳定性。     

聚氨酯/碳纳米管复合材料力学及电性能研究

利用超声分散和原位聚合的方法制备了聚氨酯／碳纳米管((PUR／CNTs)复合材料,观察了该复合材料的微观结构,探讨了CNTs含量对复合材料力学性能和电性能的影响。结果表明,CNTs在基体中获得了较好的分散,当CNTs质量分数为2％时复合材料的力学性能得到全面提高,与PUR相比,拉伸强度提高11．6％,拉伸弹性模量提高11．3％,断裂伸长率提高10．4％;复合材料的导电性能得到明显的提高,在CNTs质量分数为0．5％时可用作抗静电材料。     

PA6/CF/EG导电复合材料的制备与性能

采用熔融共混法制备了不同碳纤维/热膨胀石墨(CF/EG)比例的尼龙6/碳纤维/热膨胀石墨(PA6/CF/EG)导电复合材料并研究其性能。结果表明,CF的加入能显著提高复合材料的力学性能;而随着EG含量的提高,复合材料的导电性能和导热性能显著提高,但力学性能在一定程度上得到降低。当CF质量分数为20%时,复合材料具有最优的力学性能,当EG质量分数为20%时,复合材料体积电导率可显著提高至0.262 S/m,热导率可达1.3379W/(m·K)。     

纳米碳管/高密度聚乙烯复合材料性能的研究

应用熔融共混法制备纳米碳管／高密度聚乙烯复合材料。考查了纳米碳管含量及制备工艺对材料电性能和力学性能的影响。结果表明加入纳米碳管可以显著提高高密度聚乙烯的导电性，电阻率变化呈现渗流现象。渗流阈值在20％～25％之间，其电阻率下降8个数量级。随纳米碳管含量的增加复合材料的模量提高，断裂伸长率下降。经过对纳米碳管进行溶液浸润预处理，复合材料的导电性和力学性能均得到改善。     

氯磺化聚乙烯的合成及应用研究进展

<正>氯磺化聚乙烯橡胶(CSM)是由高密度聚乙烯(HDPE)或低密度聚乙烯(LDPE)经氯化和氯磺化反应制得的一种特种合成橡胶。CSM的氯质量分数为25%~45%,硫质量分数为1%~2%。用高密度聚乙烯制得的氯磺化聚乙烯呈线型结构,而用低密度聚乙烯制得氯磺化聚乙烯呈支链结构。与其他饱和弹型弹性体一样,CSM的耐日光老化、耐臭氧及耐化学药品性远优于含双键的不饱和型弹性体。另外,由于氯的引入而使     

HDPE／炭黑导电复合材料的改性

本文研究了导电炭黑的品种、含量及其对高密度聚乙烯（ＨＤＰＥ）性能的影响，以及动态硫化对改善ＨＤＰＥ／导电炭黑复合材料物性的贡献。结果表明，ＨＧ－４型导电炭黑填充ＨＤＰＥ具有很好的导电性，复合材料力学性能较差；ＡＣＥＴ炭黑导电性较差，复合材料力学性能最好。炭黑并用能有效地降低生产成本，而且保持了材料的性能。动态硫化法可以克服复合材料物性差的弱点，并能保持改性材料的高导电性。在ＨＧ－４型炭黑含量为７份时，材料的拉伸强度１３ＭＰａ，断裂伸长率３５０％，体积电阻率为２．１Ω·ｃｍ。     

Ni—LDPE复合材料的研究

报道了Ni-LDPE复合材料中镍粉含量对材料的导电性及力学性能影响的研究结果。实验表明,在低密度聚乙烯中加入片状镍粉以后,随着镍粉含量的增加,导电性上升,但力学强度先上升后下降。在镍粉体积分数为8％～15％时,电阻率急剧下降,然而力学强度仍然上升,直至达最大值后才急剧下降。这说明,在此期间镍粒子之间巳能充分接近、接触,形成导电通路;但是,如果聚乙烯份量太少,镍粒子被润湿、粘结不充分时,力学强度就会恶化。总之,复合材料的结构对其导电性及力学强度同时产生强烈的影响。     

高密度聚乙烯/石墨导电复合材料的制备及研究

采用高密度聚乙烯(HDPE)为基体材料,石墨为导电填料,通过物理共混法制备其导电复合材料。对不同石墨添加量的导电复合材料力学性能、热性能和导电性能进行测定,分析了石墨对其复合材料性能的影响。结果表明,不同石墨添加量的复合材料均具有良好的力学性能;石墨填料能够同时改善复合材料的导热性能和热稳定性;石墨能够降低HDPE基复合材料的电阻率,改善材料导电性。     

芦苇纤维增强低密度聚乙烯复合材料力学性能研究

以芦苇纤维作增强剂,制备了低密度聚乙烯(PE-LD)/芦苇纤维复合材料,研究了芦苇纤维、马来酸酐接枝低密度聚乙烯(PE-LD-g-MAH)及硅灰石的含量对PE-LD/芦苇纤维复合材料力学性能的影响.结果表明,未加入增容剂PE-LD-g-MAH时,随芦苇纤维含量的增加,复合材料的拉伸强度和弯曲强度先略有增加而后降低,冲击强度则呈下降趋势;PE-LD-g-MAH提高了复合材料的拉伸强度和弯曲强度,当PE-LD-g-MAH质量分数为10％时,复合材料的力学性能最好;硅灰石及芦苇纤维的质量分数分别为10％和20％时,复合材料具有较好的力学性能.     

含碳纳米管导电PET纤维的研究

将纳米组装高分子(PEEM)作为载体,使碳纳米管(CNT)及金属氧化物在其中充分分散,分别制成CNT母粒和导电剂,再与聚酯切片共混纺丝制备导电PET纤维。探讨了CNT母粒含量、导电剂含量、导电剂／CNT母粒配比、纤维的导电性能以及导电纤维的耐洗涤性、力学性能。研究结果表明:在CNT质量分数为0.18％、导电剂质量分数为2％时,制得导电PET纤维的体积比电阻为3.86×108 Ω·cm,且力学性能较纯PET下降不大。通过浸泡水洗,其体积比电阻基本不变,说明其具有优良、比较稳定的导电性和耐洗涤性。对纤维导电机理做了初步探讨。     

Preparation of conductive polyaniline/chlorosulfonated polyethylene composites via in situ emulsion polymerization and study of their properties

The conductive composites of polyaniline (PAn) and chlorosulfonated polyethylene (CSPE) were prepared by polymerization of aniline in the presence of CSPE, using a direct, one‐step in situ emulsion polymerization method. The polymerization of aniline was performed in an emulsion comprising water and xylene containing CSPE in the presence of dodecylbenzene sulfonic acid, which acts both as a surfactant and a dopant for PAn. The composites can be processed by either melt method (MP) or solution method (SP). Conductivity of the composites obtained by different processing methods shows different percolation thresholds: 14 wt % for MP samples and 22 wt % for SP samples. At the same content of PAn, the conductivity of MP composites is higher than that of SP composites. The relationships between mechanical properties and PAn content obtained by the two different processing methods were also investigated. When PAn content of MP samples is between 12 and 18 wt %, the composites behave like a thermoplastic elastomer with tensile strength at 6–8 MPa, ultimate elongation > 400% and permanent set < 30%. The conductivity of composites obtained by SP method after secondary doping with m‐cresol is about 6 orders of magnitude higher than the original at below 18 wt % PAn content and the percolation threshold for conductivity is lowered to 3 wt % PAn content. The composite shows no electrochromic activity in acidic solution of LiClO₄ in propylene carbonate, but after secondary doping exhibits electrochromic activity even in neutral electrolyte. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 845–850, 2000     

Change of conductivity of polyaniline/(styrene–butadiene–styrene) triblock copolymer composites during mechanical deformation

A measuring method for a conductivity change through a current change during extension deformation or compression deformation of conductive elastomeric composites composed of a polyaniline (PAn)/styrene–butadiene–styrene (SBS) triblock copolymer was established. The composites were prepared by in situ emulsion polymerization of aniline in the presence of SBS using dodecylbenzene sulfonic acid (DBSA) as an emulsifier and a dopant. The product was melt‐processed (MP), solution‐processed (SP), or secondary doped with m‐cresol (SSP). The results for measurement of the conductivity change of the composites processed by the three different methods showed that for the MP and SP samples conductivity increases with extension, whereas for the SSP sample when the PAn content is lower than the percolation threshold, conductivity diminishes with increasing extension, but when the PAn content exceeds the percolation threshold value, conductivity followed an empirical equation with a maximum value. During compression, the conductivities of most of the MP, SP, and SSP samples exhibited a maximum value with change of the compression force, except the MP sample with a higher PAn content, the conductivity of which increased with the compression force. All the differences are related to their different morphological structures. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2156–2164, 2000     

Preparation of conductive polyaniline‐sulfonated EPDM ionomer composites from in situ emulsion polymerization and study of their properties

The composites of polyaniline (PAn) and zinc sulfonated ethylene–propylene–diene rubber (EPDM) ionomer were made by polymerization of aniline in the presence of the ionomer by using a direct, one‐step in situ emulsion polymerization technique. The ionomers were prepared by sulfonation of EPDM rubber with acetyl sulfate in petroleum ether, followed by neutralization with zinc acetate solution. The ionomers with sulfonate contents of 10, 24, and 42 mmol SO₃H/100 g were used for preparation of PAn/ionomer composites. The in situ polymerization of aniline was carried out in an emulsion comprising water and xylene containing the ionomer in the presence of dodecyl benzene sulfonic acid, acting as both a surfactant and a dopant for PAn. The composite was characterized by IR and WAXD. The composite obtained can be processed by melt method. The conductivity of the composite with lower sulfonate content was higher than that with higher sulfonate content. Conductivity of the composites exhibits a percolation threshold at about 13 wt % PAn. When the sulfonated content is 10 or 24 mmol SO₃H/100 g and PAn content is 4–10 wt %, the composites behave as a thermoplastic elastomers with high ultimate elongation and low permanent set. The conductivity of the composite after secondary doping with m‐cresol is higher than the composite before secondary doping by about one order. Addition of zinc stearate as an ionic plasticizer lowers both the conductivity and the mechanical strength of the composites. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2211–2217, 2004     

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     

Synthesis and characterization of organo‐attapulgite/polyaniline‐dodecylbenzenesulfonic acid based on emulsion polymerization method

Organo‐attapulgite (OAT) was obtained by pretreating attapulgite (AT) with hexadecyltrimethyl ammonium bromide (HDTMABr) and dodecylbenzenesulfonic acid doped polyaniline (PAn‐DBSA) (OAT/PAn‐DBSA) was synthesized by emulsion polymerization at different OAT weight ratios. The perhaps polymerization procedure was supposed. The chemical structure and electronic absorption of the composites was confirmed by FTIR and UV–Vis spectroscopy, respectively. According to the X‐ray diffraction (XRD) results, it can be concluded that HDTMABr and PAn‐DBSA was just adsorbed on the surface of AT during the cation‐exchange process and OAT respectively without destroying the crystalline structure of AT or OAT. The composites showed a higher thermal stability than pure PAn‐DBSA by introduction of OAT into this polymerization system by using TGA analysis. Morphologies of the samples were confirmed by TEM and it showed that OAT was dispersed well in organic solvent after AT was pretreated with HDTMABr. The morphologies of OAT/PAn‐DBSA also supported the perhaps formation procedure we hypothesized. The electrical conductivity of the composite decreased with increasing the feed weight ratios of OAT in this polymerization system. POLYM. COMPOS., 2008 © 2007 Society of Plastics Engineers     

环氧树脂/玻璃布/BN导热复合材料的制备与性能研究

采用高温模压成型法制备环氧树脂(EP)/玻璃布/氮化硼(BN)导热复合材料。探讨了BN用量和偶联剂处理对复合材料力学性能、导热性能和介电性能等影响。结果表明:当w(BN)=15%时,复合材料的冲击强度较高;导热性能随着BN用量的增加而增大;当w(BN)=25%时,改性复合材料的热导率为0.901 2 W/(m.K),此时复合材料仍保持较低的介电常数和介电损耗。当BN用量相同时,偶联剂表面处理可有效改善复合材料的力学性能和导热性能。     

原位聚合法制备钼酚醛树脂纳米复合材料的研究

采用原位聚合法，用表面处理过的二氧化硅(SiO2)纳米粒子对钼酚醛树脂进行填充改性，制备了钼酚醛脂／SiO2纳米复合材料，研究了SiO2纳米粒子填充改性对复合材料耐热性和力学性能的影响。实验结果表明，SiO2质量分数为2％时，材料的耐热性和冲击强度达到最大值，分别为105℃和4．3kd／m^2；SiO2质量分数为4％时，材料的拉伸模量和拉伸强度达到最大值，分别为1288MPa和30．3MPa。     

新型阳离子型水性聚氨酯-脲乳液的合成研究

由聚酯多元醇(JW 2503)与甲苯二异氰酸酯(TD I)预聚后,经二乙烯三胺(DETA)扩链、环氧氯丙烷封端、冰乙酸中和制得了新型阳离子型水性聚氨酯-脲(WPUU)乳液。用FT-IR等方法对制备的WPUU乳液结构及有关性能进行了分析和表征。讨论了初聚n(NCO)/n(OH)、DETA的加料方式、DETA质量分数及中和度等因素对WPUU乳液及其涂膜性能的影响。研究结果表明,当初聚n(NCO)/n(OH)=2.4~2.6、DETA=6%~7%及中和度为90%~100%,且采用饥饿加料方式时,制得的WPUU乳液的贮存稳定性在12个月以上。WPUU涂膜具有较好的耐水性和耐化学品性能,WPUU涂膜的硬度(邵氏A)46,拉伸强度7.8 MPa,断裂伸长率760%,脆性温度-30℃。     

高热导率聚丙烯/石墨复合材料的制备与性能

为了提高聚丙烯(PP)的导热性能,扩大其使用范围,采用价格低廉的商用石墨对PP进行改性,利用转矩流变仪制备了PP/石墨导热复合材料。研究了粒径为2μm和20μm的石墨及其复配对复合材料热导率及力学性能的影响。结果表明,复合材料的热导率随着石墨用量的增加而显著增大,20μm石墨填充的复合材料热导率高于2μm石墨填充的复合材料;由于石墨的各向异性,层内热导率远高于层间热导率;将两种粒径的石墨复配,固定石墨总质量分数为40%,当2μm石墨与20μm石墨质量比为1︰5时,复合材料层间和层内热导率达到最大,分别为1.125 W/(m·K)和2.897 W/(m·K),比相同用量下单一2μm石墨填充PP分别提高了121%和61%,比单一20μm石墨填充PP分别提高了3.6%和20%。随石墨用量增加,单一粒径石墨填充的复合材料拉伸强度和弯曲强度呈现先减小后增大的趋势,随复配填料中20μm石墨用量增加,复配填料填充复合材料的力学性能呈下降趋势,但弯曲强度变化不大,拉伸强度也在10 MPa以上。     

马来酸酐改性聚醋酸乙烯酯乳液的研究

以马来酸酐(MA)作为醋酸乙烯酯(VAc)的改性共聚单体,采用半连续种子乳液聚合法合成了改性聚醋酸乙烯酯(PVAc)乳液,并考察了MA含量对VAc/MA共聚乳液性能的影响。结果表明:当w(MA)=0.3%～0.4%(相对于VAc质量而言)时,改性乳液的聚合稳定性、储存稳定性和稀释稳定性良好;随着MA含量的不断增加,种子反应阶段回流时间延长,共聚速率变慢,最终合成的改性乳液黏度逐渐增大;当w(MA)=0.4%时,改性乳液的综合性能相对最好,其粘接强度(9.70 MPa)比VAc均聚乳液增加了70%。