四甲基二乙烯基二硅氧烷的气质联用分析

采用气质联用方法对四甲基二乙烯基二硅氧烷样品进行分析,共检出6个组分,经分析为乙醇、二氯甲烷、二甲基乙氧基乙烯基硅烷、四甲基二乙烯基二硅氧烷、四甲基乙烯基丙烯基二硅氧烷和三甲基三乙烯环三硅氧烷.分别对其裂解机理进行讨论,其中多为合成中产生的副产物.对组分含量进行了FID测定,为四甲基二乙烯基二硅氧烷的质量控制和分析提供...     

高撕裂强度加成型医用液体硅橡胶的研制

以八甲环四硅氧烷(D_4)或二甲基环硅氧烷混合物(DMC)及四甲基四乙烯环四硅氧烷为原料、1,1,3,3-四甲基-1,3-二乙烯基硅氧烷或六甲基二硅氧烷为封端剂,经催化聚合制得不同乙烯基含量的乙烯基硅油;以酸催化合成了含氢硅油;以白炭黑为填料,六甲基二硅氮烷、四甲基二乙烯基二硅氮烷等为结构控制剂来进行密炼等工序制备实验所需要的基胶;以多乙烯基硅油为集中交联剂,制备了高撕裂强度的医用透明液体硅橡胶。探讨了白炭黑比表面积及用量、多乙烯基硅油的用量、四甲基二乙烯基二硅氮烷的添加量对液体硅橡胶撕裂强度的影响。结果表明,要制备高撕裂强度的医用液体硅橡胶,必须添加一定量的多乙烯基硅油,并且四甲基二乙烯基二硅氮烷的添加对促进撕裂强度的增长有很大的作用。当乙烯基硅油100份、比表面积为250 m~2的白炭黑29份、多乙烯基硅油4份、四甲基二乙烯基二硅氮烷用量为白炭黑质量的3%所制得的液体硅橡胶,其撕裂强度能达51 k N/m、邵尔A硬度61度、拉伸强度9.2 MPa、拉断伸长率500%。     

膜用高乙烯基含量硅橡胶的合成与表征

以八甲基环四硅氧烷(D4)和四甲基四乙烯基环四硅氧烷(Dvi4)为单体、四甲基二乙烯基二硅氧烷(Mmvi)为封端剂、氢氧化钾为催化剂,合成了乙烯基摩尔分数为5%的硅橡胶PVDMS.研究了反应时间、反应温度及Mmvi加入量对产物黏度的影响,得到的最佳合成条件为反应温度140℃、反应时间180～210 min、MMvi质量分数0.9%～1.8%.用傅里叶变换红外光谱和核磁共振氢谱对其结构进行了表征,并计算了产物中的乙烯基含量,得到的结果与预期值相一致.将产物与国外牌号为184和VP7660的产品进行了膜性能比较,结果表明所得PVDMS性能良好,可替代进口硅橡胶产品.     

低摩擦系数硅橡胶胶料

配合(质量份)；甲基乙烯基硅橡胶(乙烯基含量0.15mol％)；沉淀法白炭黑 30；羟基硅油 5；含氢硅油 1.2；氯铂酸／辛醇溶液(铂含量，质量份数1％)O.03；四甲基四乙烯基环三硅氧烷0.25。     

碱催化制备低黏度甲基硅油和乙烯基硅油

以二甲基环硅氧烷混合物为原料、六甲基二硅氧烷和1,1,3,3-四甲基-1,3-二乙烯基硅氧烷为封端剂,经碱胶催化聚合制得低黏度二甲基硅油和乙烯基硅油,考查了六甲基二硅氧烷（MM）用量对甲基硅油黏度的影响,反应时间对转化率的影响,乙烯基双封头用量对乙烯基硅油性能的影响。结果表明：使用碱催化聚合反应,聚合周期短、挥发分低,通过调节MM的加入量易对甲基硅油的黏度进行控制,制备甲基硅油时最优聚合反应为3h时,硅油转化率为90％以上;制备乙烯基硅油时,通过调节1,1,3,3-四甲基-1,3-二乙烯基硅氧烷的用量可以调节乙烯基硅油中的乙烯基摩尔分数。     

端乙烯基硅油的制备及流变特性研究

以八甲基环四硅氧烷(D4)、二乙烯基四甲基二硅氧烷(亦称乙烯基双封头)为原料,氢氧化钾碱胶为催化剂,采用开环聚合反应制备端乙烯基硅油。考察了聚合温度、聚合时间、物料配比等对单体转化率的影响。结果表明,聚合温度和时间对D4转化率的影响不显著,但对乙烯基双封头的转化率影响显著,随着温度由130℃提高到150℃,乙烯基双封头的转化率由54.62%升高至86.73%;随着聚合时间由3 h延长至6 h,乙烯基双封头的转化率由52.87%升高至86.02%。最佳聚合温度为150℃、聚合时间为6 h。采用旋转黏度计研究端乙烯硅油的黏度随剪切速率的变化。端乙烯基硅油为胀流性流体,其流动规律满足通式ηa=Krn-1。     

双端乙烯基氟硅油的研制

以1,3,5-三甲基-1,3,5-三(3,3,3-三氟丙基)环三硅氧烷为原料、四甲基二乙烯基二硅氧烷为封端剂、硫酸为催化剂制得双端乙烯基氟硅油,研究了反应时间、催化剂用量、反应温度对产物黏度和挥发分质量分数的影响;采用红外光谱和核磁共振波谱表征了产物结构.结果表明,产物为双端乙烯基氟硅油.较佳的制备条件为反应时间1 h...     

高折射率乙烯基苯基硅油的制备及其LED封装材料性能

以甲基苯基硅氧烷环体(DnMe,Ph(n=3,4,5))和四甲基四乙基环四硅氧烷(D4Vi)为原料,自制高效催化剂,以六甲基二硅氧烷(MM)为封端剂,采用一步开环聚合的方法,成功制得高折射率乙烯基苯基硅油。通过改变反应温度、反应时间和封端剂的用量这三个影响因素,得到最佳制备工艺。对制得的样品进行ATR-FTIR、TG、1H-NMR、折射率测试、透光率测试等测试和表征,制备的产物折射率达到1.54以上、透光率达到90%以上,达到了进口产品性能。将制得的乙烯基苯基硅油按一定配方进行硅氢化反应,用DSC、DMA等表征固化性能。结果表明,自制的乙烯基苯基硅油苯基含量达34%,具有高耐热性,可以满足LED封装的要求。     

氟硅树脂的制备及其性能研究

以单体三氟丙基甲基环三硅氧烷(D3F)、四甲基四乙烯基环四硅氧烷为原料,以平均相对分子质量为3 000、乙烯基摩尔分数为10％的乙烯基氟硅油作封端剂,以硅氧烷醇钠作催化剂,聚合成平均摩尔质量约8×10 5g/mol、乙烯基含量0.5％的氟硅树脂。讨论了催化剂用量、反应温度及时间原料中水分的含量、乙烯基含量和中和剂对氟硅树脂性能的影响。结果表明:采用高纯度D2F,硅氧烷醇钠催化剂用量为0.4％,在(130±5)℃反应60min制备出的氟硅树脂经硫化测试,其邵氏硬度为71,撕裂强度为31.5kN/m,拉伸强度8.6MPa,断裂伸长率404％,其结果表明符合市场使用要求。     

乙烯基封端甲基苯基硅油的制备及其性能表征

以甲基苯基环硅氧烷为原料,二乙烯基四甲基二硅氧烷为封端剂,在催化剂四丁基氢氧化铵作用下,采用阴离子聚合法制备了不同分子质量的乙烯基端基甲基苯基硅油;并进行了1H-NMR、GPC、动力黏度、折射率等性能表征。将苯基硅油进行交联固化,测量了其透光率及硬度。     

端乙烯基硅油对RTV-2泡沫硅橡胶性能的影响

以α,ω-二羟基聚二甲基硅氧烷(107硅橡胶)、α,ω-二乙烯基聚二甲基硅氧烷(端乙烯基硅油)、含氢硅油、气相法白炭黑、抑制剂、发泡剂及催化剂为原料,制得双组分室温硫化(RTV-2)泡沫硅橡胶。探讨了端乙烯基硅油黏度和用量对RTV-2泡沫硅橡胶的初始黏度、操作时间、发泡倍率、力学性能、硬度及外观形貌的影响。结果表明,随着端乙烯基硅油黏度的增加,RTV-2泡沫硅橡胶的发泡倍率增加,泡孔孔径及骨架变细,弹性更好,胶料的初始黏度增加、操作时间缩短、硬度增加、泡孔孔径逐渐变小,拉伸强度先降后增,伸长率变化不明显;且随着端乙烯基硅油用量的增加,RTV-2泡沫硅橡胶的发泡倍率减小,泡孔孔径及骨架会先细后粗。当加入3～9份8 000 mPa·s的端乙烯基硅油时,可制得流动性好,操作时间长、发泡倍率高、泡孔孔径细及弹性好的泡沫硅橡胶。     

Synthesis and effects of MDT silicone resin on PMPS‐based ablative composites

A novel methylphenyl silicone resin, with M, D, and T units, was synthesized by cohydrolysis and cocondensation method from dimethyldimethoxysilane (Me₂Si(OMe)₂), phenyltrimethoxysilane (PhSi(OMe)₃), hexamethyldisiloxane, and 1,3‐divinyl‐1,1,3,3‐tetramethyldisiloxane in toluene/water mixture catalyzed by hydrochloric acid and trifluoromethanesulfonic acid. The vinyl end‐capped MDT silicone resins were chosen for reinforcement filler to enhance the mechanical properties of silicone‐based ablative composites. The effects of resins with various R/Si ratios, vinyl content, and loadings on mechanical properties of PMPS rubbers were investigated. It was revealed that on the premise of good fluidity and processing performance, MDT resin showed excellent reinforcing effect and thermal stability compared with silica. MDT reinforced ablative composite showed satisfactory mechanical and antiablative properties. The linear ablation rate was 0.01 mm/s, which maybe associated with high yield of charred residue in thermogravimetric analysis results. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41571.     

乙烯基硅油改性苯丙乳液粘合剂的制备及应用

采用丙烯酸酯单体制备苯丙乳液粘合剂,用乙烯基硅油对其进行改性。探讨了乙烯基硅油的用量对乳液性能、胶膜性能的影响,及硅油改性粘合剂的用量对棉织物印花性能的影响。对改性粘合剂进行了红外光谱、热重分析、透射电镜等表征。结果表明,乙烯基硅油用量为9%时,乳液外观、胶膜及印花性能较好;乙烯基硅油改性粘合剂用量为6%时,印花织物的手感柔软、摩擦牢度较好。     

LED封装胶专用增粘剂的制备

以羟基硅油、γ-（2,3-环氧丙氧）丙基三甲氧基硅烷（KH 560）、乙烯基三甲氧基硅烷等为原料,制得LED封装胶专用增粘剂。研究了增粘剂合成工艺对聚邻苯二酰胺树脂（PPA）及金属粘接性的影响。结果表明,制备增粘剂的较佳工艺为：羟基硅油、KH 560、乙烯基三甲氧基硅烷的量之比为1.0∶1.0∶0.5,二月桂酸二丁基锡的质量分数为250×10^-6,在温度60～65℃下保温反应4 h;将此增粘剂按LED封装胶总质量的1.25%加入到B组分中配成封装胶,用于5050、5730灯架的封装测试,过3次回流焊,然后在100℃沸腾的红墨水中连续煮18 h,红墨水不渗入灯珠内杯周边及底部。     

影响HTV硅橡胶撕裂强度的因素

考察了白炭黑种类、羟基硅油用量、含氢硅油用量以及不同乙烯基含量生胶并用对热硫化(HTV)硅橡胶撕裂强度的影响。结果显示,气相法白炭黑的补强效果强于沉淀法白炭黑,且比表面积越大,硅橡胶的撕裂强度越高;随着羟基硅油加入量的增加,硅橡胶的撕裂强度先增后趋于稳定;含氢硅油的用量对HTV硅橡胶的撕裂强度基本没有影响;高乙烯基含量生胶和低乙烯基含量生胶并用能显著提高HTV硅橡胶的撕裂强度。较佳配方是:166 g 110-0生胶,4 g 112生胶、80 g QS-102气相法白炭黑、8.5 g羟基硅油、1.0 g含氢硅油、0.5 g乙烯基硅油,此时,HTV硅橡胶的撕裂强度达到21 KN/m。     

Silicone‐Organic Resin Hybrid Matrix Composites

Summary: Glass fabric reinforced hybrid matrix composites of a toughened silicone resin and a vinyl ester resin were fabricated and their properties investigated. The hybrid composites consisted of multi‐layers of fiber reinforced silicone resins and vinyl ester resins. The toughened silicone resin, a crosslinkable phenylsilsesquioxane resin with high thermal and thermal oxidation resistance but relatively low T_g, was chosen to be the outer layers. The vinyl ester resin, with better strength, toughness and a much higher T_g than the toughened silicone resin, was used as the inner layers. A co‐cure process proved to establish a strong interface between the two in a hybrid composite. The hybrid composites had better flammability properties and much lower short term moisture absorption than the vinyl ester composites. The strength and modulus retention of the hybrid composites at elevated temperatures was higher than the composites using any single resin as the matrix. For example, when tested at 150 °C the flexural modulus and strength values of a twelve layer composite, with eight inner vinyl ester resin layers and four silicone outer layers, were almost an order of magnitude higher than the composite using the silicone resin alone, and were significantly higher than the one using vinyl ester resin alone. The room temperature short beam shear strength of the hybrid composites was also higher. DMA revealed that the inter‐diffusion of reactive components between the two resins was probably responsible for this synergistic effect, resulting in an α transition temperature of 182 °C for the hybrid composite, higher than that of either the silicone resin (85 °C) or the vinyl ester resin (162 °C).

     

分子筛脱除碳酸酯中微量水的应用研究

研究了4A分子筛对碳酸酯物质中微量水的脱除及提纯方面的作用,考察了4A分子筛用量、吸附温度、吸附时间等因素的影响,同时对重复再生后分子筛的除水性能进行了研究,结果表明,高温活化处理后的4A分子筛对碳酸酯中的水分具有较好的吸附效果。     

Addition-cured silicone adhesive technology: Vinyl silicone crosslinker

Silicone pressure-sensitive adhesives prepared from a platinum-catalyzed, high solids silicone composition are described. The adhesive compositions consist of an MQ siloxane resin, vinyl-and hydride-terminated silicone fluids, and a multifunctional vinyl silicone crosslinker. In this study, multifunctional vinyl silicone crosslinkers of various structures, including linear polymers, T, TQ, and Q resins, were prepared and evaluated for their effect on the adhesive properties of cured silicone pressure-sensitive adhesives. Additionally, the activity of these multifunctional vinyl silicones in hydrosilylation reaction was investigated. © 1994 John Wiley & Sons, Inc.     

金属氧化物对硅橡胶和氟硅橡胶耐热性的影响

着重研究了金属氧化物对甲基乙烯基硅橡胶、甲基苯基乙烯基硅橡胶、三氟丙基甲基乙烯基硅橡胶耐热性的影响。结果表明,Ｆｅ２Ｏ３、ＦｅＯ３／ＳｎＯ２、ＳｎＯ２、ＣｅＯ２等可以显著提高硅橡胶的耐热性;光电子能谱分析结果说明,ＳｎＯ２、ＣｅＯ２在热空气老化过程中从高价态被还原到低价态,发生了多个（或单个）电子转移的氧化还原反应,从而阻止了硅橡胶的热氧化自由基链增长,提高了硅橡胶的耐热空气老化性能。