有机硅泡沫材料的制备

以羟基封端硅氧烷为基体制备有机硅泡沫材料并分析其反应机理.分析了有机硅泡沫材料的反应原理,通过对羟基硅油黏度、催化剂种类及其用量、成核剂种类的筛选,确定了制备有机硅泡沫材料的配方:羟基硅油100g、乙烯基硅油10g、含氢硅油19g、季铵碱5g、纳米碳酸钙9g、自由发泡温度173℃,发泡时间15min,在此条件下能够制得发泡倍率较高,泡孔无塌陷、耐热性突出的有机硅泡沫材料.     

分子结构对室温硫化硅橡胶泡沫材料影响的研究

采用不同苯基结构或含量的端羟基聚有机硅氧烷为生胶,制备了4种密度相近的室温硫化硅橡胶泡沫材料,就生胶分子结构对硅橡胶的硫化特性、泡沫材料的泡孔结构及压缩性能的影响进行了研究。结果表明,端羟基聚有机硅氧烷分子中的苯基对室温硫化硅橡胶的硫化性能以及泡沫材料的泡孔结构和压缩性能有明显的影响,苯基的位阻效应会降低胶料的硫化速率,有利于获得泡孔细小均匀的泡沫材料,同时降低泡沫材料的应力松弛率。     

表面可修饰性聚有机硅氧烷密封材料及其制备方法（CN1613949）

本发明的表面可修饰性聚有机硅氧烷密封材料组分及其按重量份数计的含量如下：羟基封端的聚有机硅氧烷：100份，填料：5-200份，交联剂：0．1～20份，催化剂：0．01～10份，增粘添加剂：0．1～10份。制备方法是将羟基封端的聚有机硅氧烷、填料、催化剂、交联剂和增粘添加剂按重量份数配比于真空条件下混合制备而成。[第一段]     

封端型聚醚改性聚硅氧烷非离子表面活性剂的合成

以低含氢硅油、α-烯丙基聚醚等为原料,经烷基封端、硅氢加成等反应制备了封端型聚醚改性聚硅氧烷非离子表面活性剂,讨论了温度、催化剂以及聚醚结构等对封端率的影响。结果表明,采用以氢氧化钠和碳酸钠制备的缓释性复合碱为催化剂的一步法封端工艺,在反应温度25~65℃条件下,α-烯丙基聚醚的烷基封端率可达85%以上。封端型聚醚改性有机硅表面活性剂可用于单组分聚氨酯密封胶、高回弹和软质聚氨酯泡沫的泡沫稳定剂。     

羟基封端聚甲基苯基硅氧烷的制备及表征

以低摩尔质量的羟基硅油和甲基苯基环硅氧烷为原料、四甲基氢氧化铵[(CH3)4NOH]硅醇盐为催化剂,通过平衡共聚反应制备了羟基封端聚甲基苯基硅氧烷.研究了原料配比、催化剂用量、反应时间、反应温度等因素对聚合物制备的影响.通过红外光谱,热裂解气质联用等方法对制备的产物进行了结构表征.结果表明,当(CH3)4NOH质量分数为0.04%, 反应温度110 ℃,反应时间为6 h,甲基苯基硅氧链节与二甲基硅氧链节的量之比为1:1,可制得不同苯基含量的羟基封端聚甲基苯基硅氧烷.     

脱氢型室温硫化硅橡胶的研究

考察了端羟基聚有机硅氧烷、补强填料和含氢硅油的种类对脱氢型室温硫化(RTV)硅橡胶的力学性能和粘接性能的影响,以及催化剂种类对RTV硅橡胶的凝胶时间和表观密度的影响。结果表明,当端羟基聚二甲基硅氧烷和端羟基聚甲基苯基硅氧烷按10∶3的质量比并用时,RTV硅橡胶的剪切强度较高;当侧氢基硅油和端氢基硅油按1∶1~1∶3的质量比配合使用时,能明显改善硅橡胶的剪切强度;通过选择适当的催化剂,可调整脱氢型硅橡胶的凝胶时间,制得较致密的硫化胶;二氧化钛、氧化锌对脱氢型RTV硅橡胶均有补强作用,而经甲基三乙氧基硅烷处理的氧化锌对脱氢型RTV硅橡胶的补强作用最明显。     

环氧基改性聚甲基硅氧烷的合成及其在热转印色带中的应用研究

在Karstedt's催化剂的催化下,通过含氢硅油与4-乙烯基-1,2-环氧环己烷(VCHO)的硅氢加成反应,制得了环氧改性聚有机硅氧烷;考察了加料方式、抑制剂种类、含氢硅油中活性氢的质量分数、反应温度及催化剂用量对反应的影响.结果表明:在VCHO浓度较高时,催化剂中Pt的最终形态为铂胶体,导致产品呈现黄色;含氢硅油中活性氢的质量分数越高,反应体系越容易发生凝胶;乙醇可有效抑制环氧化合物的开环聚合反应;制备环氧基改性聚硅氧烷的最佳反应条件是:催化剂用量为含氢硅油质量的0.45%、抑制剂乙醇的用量为含氢硅油质量的15%、反应温度为80℃、加料方式是先将催化剂加入VCHO中再滴加含氢硅油.热转印碳带的背面涂布采用在此条件下合成的环氧基改性聚硅氧烷配成的紫外光固化涂料时,打印效果最好.     

一种表面可修饰性的有机硅密封胶及其制备方法

本发明公开了一种表面可修饰性的有机硅密封胶及其制备方法,它的组分及其按重量份数计的含量如下：羟基封端的聚有机硅氧烷100份,羟基封端的改性聚有机硅氧烷10-50份,填料5-200份,交联剂1-10份,催化剂0.01-2份,增粘剂0.1-10份。制备步骤：先将填料干燥,     

乙烯基硅油对水作羟基供体制备发泡硅橡胶的影响机理分析

采用去离子水作为羟基供体与含氢硅油在铂催化条件下反应生成气体，用乙烯基硅油制备发泡硅橡胶，分析乙烯基硅油特性对发泡硅橡胶的影响机理。结果表明：乙烯基硅油粘度为22 000 mPa·s时，发泡硅橡胶的密度和泡孔直径较小，发泡倍率较大，物理性能较好；水作为羟基供体与含氢硅油反应制备发泡硅橡胶依靠的是乙烯基硅油粘度与乙烯基含量的双重作用。     

柔性链光敏有机硅预聚体的制备与性能研究

以乙烯基硅油、端氢硅油、甲基丙烯酸羟乙酯、硅烷偶联剂等为原料,通过硅氢加成反应、烷氧基团置换等途径,制备了一种柔性链光敏有机硅预聚体.采用红外光谱、热重分析以及固化时间、固化深度和固化物硬度及拉伸性能测试研究了预聚体的光固化特性及其光固化材料的力学性能与热稳定性.结果 表明:该有机硅预聚体具有较好的光聚合反应性能,可光...     

聚二甲基硅氧烷涂层材料的研究

采用一定粘度的聚二甲基硅氧烷为基体,加入适量填料和助剂,成功制备了室温硫化硅橡胶涂层。研究了气相法SiO2和交联剂对涂层材料的影响,并进行了TG和SEM测试。研究结果表明：填料的添加明显改善了涂层的力学性能和耐高温性能,拉伸强度迭1．42MPa,可耐温288℃;并且该涂层有较好的耐水和耐酸、盐性能,耐碱性能有待进一步改善。     

单组分脱醇型有机硅密封胶制备工艺及其性能的研究

以端羟基聚二甲基硅氧烷、碳酸钙、交联剂、粘接促进剂及催化剂为原料制备了单组分脱醇型有机硅密封胶.研究了制备温度、粘接促进剂种类、加料顺序对密封胶力学性能、黏度、外观、抗黄变性能的影响.结果表明,制备温度在30℃以下,密封胶具有良好的力学性能和外观;使用复配的胺类和环氧类粘接促进剂,密封胶在使用过程中长期不黄变;加料顺序...     

Polyurethane methacrylate/silicone interpenetrating polymer networks synthesis,thermal and mechanical properties

The synthesis of an interpenetrating polymer network (IPN) combining a polyurethane methacrylate network (PUMA) and a silicone network is reported. The PUMA network is synthesized by UV-light cure. The silicone network is formed through a condensation between α, ω dihydroxy polydimethyl siloxane and γ-methacryloxypropyl trimethoxy silane (γ-MPS) as a cross-linking agent. The IPN is prepared by different mechanism: radical and condensation types. According to thermogravimetric analysis of the hybrid material, the thermal stability stayed unchanged but the kinetic of degradation changed. Tg decreased with increasing silica content. The thermal cure process under humid atmosphere influence properties just for PUMA/4.2%Si^UV+T. Condensation between γ-MPS decreases the penetration depth from 158 to 82 μm and increases the mechanical glass transition temperature from 106 to 141 °C.     

Blends of polycarbonate and polysulphone–polydimethyl–siloxane block copolymers: analysis of compatibility and impact strength

The possibility of modifying polycarbonates by using dian (Bisphenol A) polysulphone–polydimethyl siloxane block copolymers having multiblock structure and triblocks with end polydimethyl siloxane or a polysulphone block structure was shown. In triblock copolymers the polydimethyl siloxane blocks have a constant molecular weight equal to 2500, while in polyblocks it was assumed to be 2500 and 10,000. The molecular weight of polysulphone blocks varied between 700 and 9000 in triblocks or between 500 and 4500 in polyblocks. It was found that block copolymers of both multi- and triblock structure with polydimethyl siloxane end blocks of concentration 45–68 wt % are created with PC microheterogenous blends. These blends, in a wide temperature interval (from cryogenic to the glass transition temperature of PC), have high impact strength when multiple crazes are created independently on testing temperature. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 1823–1834, 1999     

Role of surface active additives on reduction of surface free energy and enhancing the mechanical Attributes of easy-to-clean automotive clearcoats: Investigating resistance against simulated tree gum

The objective of this work is enhancing the clearcoat resistance against simulated tree gum (Arabic gum) using surface active additives including hydroxyl-functional polydimethyl siloxane (PDMS) and hydroxyl-functional silicone polyacrylate which are able to reduce gum adhesion to the clearcoat surface by reducing its surface free energy and work of adhesion. Using a contact angle measuring device, the surface free energy, contact angle and work of adhesion were obtained. The mechanical and structural properties of the clearcoats were studied by tensile test, dynamic mechanical thermal analysis (DMTA) and Fourier transform Infrared spectroscopy (FT-IR). Results showed that both additives enhanced the clearcoat easy-to-clean properties and reduced work of adhesion and surface free energy. The decrease in surface free energy and work of adhesion was more pronounced in presence of hydroxyl-functional polydimethyl siloxane. It was found that polydimethyl siloxane could produce contact angles much greater than silicone polyacrylate. Both additives increased clearcoat cross-linking density and toughness by participating in curing reaction. Results showed that the increase in cross-linking density and toughness was more effective when polydimethyl siloxane based additive was used. Results also revealed that additives could significantly improved the clearcoat resistance against Arabic gum by reducing gum adhesion to the surface. Both number of cracks and etched areas were reduced in presence of the additives especially in presence of polydimethyl siloxane. Both the chemical structure and functionality of the additives were found influential parameters which could alter the clearcoat surface cleanability and biological resistance against simulated tree gum.     

Epoxidized pine oil‐siloxane: Crosslinking kinetic study and thermomechanical properties

In this study, a novel approach to toughen biobased epoxy polymer with different types of siloxanes was explored. Three different modified siloxanes, e.g., amine‐terminated polydimethyl siloxane (PDMS‐amine), glycidyl‐terminated polydimethyl siloxane (PDMS‐glycidyl), and glycidyl‐terminated polyhedral oligomeric silsesquioxane (POSS‐glycidyl) were used as toughening agents. The curing and kinetics of bioepoxy was investigated by differential scanning calorimetry and Fourier transform infrared spectroscopy. The mechanical, thermal, and morphological properties of the cured materials were investigated. Rheological characterization revealed that the inclusion of POSS‐glycidyl slightly increased the complex viscosity compared to the neat resin. The morphology of the cured bioresin was characterized by transmission electron microscopy and scanning electron microscopy. The inclusion of POSS‐glycidyl to bioepoxy resin resulted in a good homogeneity within the blends. The inclusion of PDMS‐amine or PDMS‐glycidyl was shown to have no effect on tensile and flexural properties of the bioresins, but led to a deterioration in the impact strength. However, the inclusion of POSS‐glycidyl enhanced the impact strength and elongation at break of the bioresins. Dynamic mechanical analysis showed that the siloxane modified epoxy decreased the storage modulus of the bioresins. The thermal properties, such as decomposition temperature, coefficient of linear thermal expansion, and heat deflection temperature were improved by inclusion of POSS‐glycidyl. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42451.     

聚氨酯有机硅匀泡剂的研究及应用

综述了近年来有机硅表面活性剂聚二甲基硅氧烷、聚醚改性聚硅氧烷作为聚氨酯泡沫塑料匀泡剂的研究进展,重点介绍了其主要品种S i─C型聚醚改性聚硅氧烷在无溶剂工艺、催化剂的制备及聚醚配方优化等方面的进展,指出目前提高国产软泡匀泡剂的产品质量是聚氨酯有机硅匀泡剂研究的发展方向。     

导电有机硅密封剂的研究

以镀银镍粉为导电填料、端羟基聚二甲基硅氧烷为基胶、经硅烷表面处理的白炭黑为补强填料,有机锡为催化剂,制成了高导电室温硫化双组分有机硅密封剂;研究了导电机理、镀银镍粉的加入量对有机硅密封剂的导电性能和电磁屏蔽性能的影响。结果表明,当镀银镍粉的体积分数超过25%时,有机硅密封剂的电性能明显提高;当镀银镍粉的体积分数达到35%以上时,有机硅密封剂的体积电阻率下降近10个数量级;当镀银镍粉的体积分数为50.5%时,有机硅密封剂在高频率范围具有良好的电磁屏蔽性能。     

Novel polymethoxylsiloxane‐based crosslinking reagent and its in‐situ improvement for thermal and mechanical properties of siloxane elastomer

Polymethoxylsiloxane (PMOS) with dense pendant silicone‐methoxy groups was synthesized from cyclosiloxane monomers by ring‐opening polymerization and dehydrocoupling reaction. Synthesis reactions were followed by IR spectroscopy and ²⁹Si NMR analyses. PMOS was used as crosslinking reagent for room temperature vulcanized polydimethylsiloxane (PDMS), and the apparent activation energy for crosslink reaction was 3.92 kJ/mol. TEM study shows that many dispersed high crosslink density PMOS phases were formed in siloxane elastomer as well as the PDMS networks, and the crosslink density increased from PDMS networks to PMOS phases gradually, without a clear interface. It was detected that these PMOS phases improved the thermal and mechanical properties of siloxane elastomer significantly because of their in‐situ microscale improvement effect. TG analysis demonstrated that thermal decomposition process of PMOS crosslinked siloxane elastomer was divided into three stages, the second one corresponding to a possible loss of some new structures, and the residual mass at 500°C was 66 wt %. The crosslink density went up as the loading of PMOS increased. Tensile stress and elastic module increased twice and three times, respectively, when the PMOS content increased from 15.1 to 41.6 wt %. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

LED用低热阻硅脂的制备

选用合适粒径的氮化铝和氧化铝为混杂导热填料、使用自制的硅烷低聚物为表面处理剂,以溶液插层法对混杂导热填料进行表面改性;然后与甲基苯基硅油混合制备了LED用低热阻导热硅脂。研究了导热填料的种类、粒径、表面处理剂种类及用量对导热硅脂的热导率和黏度的影响。采用LED灯作为实际测试平台表征了导热硅脂的导热性能。结果表明,当填料总质量分数为90.9%,粒径为5μm的氮化铝与粒径为1μm的氧化铝作混合填料且质量比为2.8∶1时,导热硅脂的热导率和黏度有较好的平衡;使用填料质量0.5%的硅烷低聚物对氮化铝和氧化铝混合填料进行表面处理有较好的处理效果;自制10号硅脂样品的黏度（25℃）为174 Pa·s,热阻为1.94℃/W,热导率为4.31 W/m·K。