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聚甲基丙烯酸甲酯新应用发展近况 总被引:1,自引:0,他引:1
真锅健二 《丙烯酸化工与应用》2001,14(4):36-41
追溯代表性的透明塑料的历史,先后相继工业化的是:聚氯乙烯1927年,聚苯乙烯1930年,甲基丙烯酸甲酯1936年,聚碳酸酯1958年,这些透明塑料当,因甲基丙烯酸甲酯树脂具出类拔萃的透明性,表面光泽,优良的耐候性,以及良好的机械特性等综合性能,被广泛用于汽车部件,弱电零部件,光学元件,广告板,显示器,照明,建材,日用杂品等,在日本其年产量约为20万吨左右,近年来,对甲基丙烯酸甲酯的物性也提出了多种多样,高层次的要求(耐冲击性,耐热性,耐溶剂性,低吸湿性,阻燃性,耐擦伤性,抗静电性,防雾性,波长选择吸收性,防污性,低反射性等),为此,针对不同用途的要求进行了质量和技术开发,此外,在近几年,随着显示材料领域的迅猛发展与其市场的扩大,通过灵活运用甲基丙烯酸甲酯本身特有的透明性进行材料设计,提供更高的光学功能,各种光学元,器件对甲基丙烯酸甲酯的需要量正在不断增长。 相似文献
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本文分析了聚甲基丙烯酸甲酯热稳定性差的产生原因及处理方法。聚甲基丙烯酸甲酯热稳定性差产生的原因是:①在聚合过程中由于歧化终止产生C=C双键,形成不稳定的终端基团;②氧气参与过程反应生成活泼的过氧自由基,在夺取聚合物中的氢原子,形成C=C双键,因而降低了聚甲基丙烯酸甲酯的热稳定性。解决方法是:通过与其它单体共聚,消除不稳定终端基团,以及使用抗氧剂消除氧气对有聚合物自由基的氧化作用。 相似文献
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聚甲基丙烯酸甲酯改性研究进展 总被引:1,自引:0,他引:1
综述了聚甲基丙烯酸甲酯(PMMA)在耐热性能、耐磨损性能、阻燃等方面改性研究的途径及国内外研究的最新进展,分析了各种改性方法的特点,并展望了PMMA改性研究今后的发展方向。 相似文献
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Thermoplastic materials used in coatings, paints and adhesives as well as structural applications for sensitive substrates, such as wood, paper or polymers, often lack the required chemical and environmental resistance for many applications, which can be overcome by covalent cross-linking. Covalent cross-linking improves chemical and mechanical properties of the material and has been used for many different materials and applications. Room temperature cross-linking can be initiated by different mechanisms and eliminates energy intensive heating as well as conditions potentially harmful for the substrate. The present article focuses on cross-linking strategies applied for different materials, such as thermoplastics and thermosets. It is organized by material class, followed by an overview about triggering mechanisms for cross-linking reactions at room temperature. The authors hope to provide helpful insights about the methods for covalent cross-linking already published. 相似文献
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Jens Peter Hermes 《Electrochimica acta》2009,54(17):4258-2989
Doping front migration is a recently discovered effect occurring in sandwich structures composed of intrinsically conductive polymers. A system based on chemical or electrochemical doping is capable of controlling an integrated display and modifying the electrical resistance of the conductive polymer. The effect does not require a battery and is capable of monitoring time and temperature exposure. Low-cost devices using doping front migration could be the basis of a new class of smart labels for applications such as electronic “best before” labels on food and drink. 相似文献
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以柔性疏水小分子N-异丙基丙烯酰胺(NIPAM)对聚苯乙烯磺酸盐(PSS)进行共聚改性,制备了一系列聚[(苯乙烯磺酸盐)-共-异丙基丙烯酰胺][P(SS-co-NIPAM)],并以其为模板采用氧化聚合法与3,4-乙烯二氧噻吩(EDOT)制备了导电聚合物PEDOT:P(SS-co-NIPAM)。与PEDOT:PSS薄膜相比,NIPAM摩尔分数(以对苯乙烯磺酸钠物质的量为基准,下同)为15%时,PEDOT:P(SS-co-NIPAM)薄膜平均透光率保持在80%左右,水接触角从18.5°增至39.0°,疏水性提高,并且弯曲1000次后方阻变化量为5.71 kΩ/sq,远小于PEDOT:PSS薄膜(10.60 kΩ/sq)。以NIPAM摩尔分数为15%的PEDOT:P(SS-co-NIPAM)薄膜作为离子储存层的电致变色器件的光学对比度(ΔT)为9.83%,循环800次后ΔT仍达到9.55%,衰减量为0.28%,衰减量与PEDOT:PSS器件相当,说明NIPAM共聚改性能改善PEDOT:PSS导电聚合物的柔韧性和疏水性,以其作为离子储存层的器件可维持优异的电致变色性能。 相似文献
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介绍了导热室温硫化硅橡胶的导热机理及导热模型,分析了室温硫化硅橡胶的导热性能及综合性能,并概述了国内外导热室温硫化硅橡胶的研究现状。指出通过填充不同粒径分布的填料或对填料进行适当的表面处理,可以制备高导热室温硫化硅橡胶。 相似文献
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研制了一种常温钢铁除油剂,工作温度为-5 ̄40℃,主要成分为氢氧化钠、硫酸钠、葡萄糖酸钠、海藻酸钠、六偏磷酸钠及助剂 。 相似文献
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A physically based, isostructural, constitutive model is described for simulating the onset of nonlinear viscoelasticity in multiaxial creep of glassy polymers, as needed in stress analyses of load-bearing components. In the linear viscoelastic limit, shear response reduces to that of a generalized Maxwell model, while hydrostatic response is Hookean. Nonlinearity enters through Eyring-type rate process kinetics. The equations of the model are solved numerically using a pseudo-linear approximation through each time step, leading to an incremental equation for stress that would be convenient for use in finite element analyses. The model and its assumptions were tested using tension, shear and combined tension/shear creep experiments on well-aged poly(methyl methacrylate) at 70°C. Reproducibility tests confirmed the assumption of constant glass structure for strains up to ~ 1.5 × 10?2. Shear and pressure activation volumes were obtained by fitting the dependence of the shear compliance on stress invariants. The data showed unequivocally that shear activation volumes vary with log(relaxation time), and excellent agreement was obtained for a linear variation, consistent with the “compensation rule” of polymer thermo-viscoelasticity. The activation volumes are large (many monome units), indicating the cooperative nature of the elementary flow process. Interestingly, they are of the same order as those applying to yield and plastic flow. Although the model finds success in simulating creep, it fails to describe so accurately the strain recovery on unloading. Possible explanations are suggested. 相似文献