EFFECTS OF SOME PHENYLETHYNYLSILICON COMPOUNDS ON HEAT-CURABLE SILICONE RUBBER Ⅲ 1, 1, 3, 3-TETRAMETHYL-1, 3-DIPHENYLETHYNYL-DISILOXANE

We have shown that some phenylethynylsilicon compounds are good cure crosslinkersof heat-curable silicone rubber(HCSR). In this paper the effects of 1, 1, 3, 3-tetramethyl-1, 3-diphenylethynyldisiloxane (TMDPDS) as a crosslinker on HCSR were studied. Thevulcanizates with fine mechanical properties could be obtained with suitable amounts ofTMDPDS. Sol fractions, and crosslinking density of vulcanizates and vulcanizationretardation effect of TMDPDS on hydrosilation curing silicone rubber were also discussed.

N-异丁酰基-3′-O-(1-氟-1,1,3,3-四异丙基-1,3-二硅氧烷-3-基)-2′-苄氧羰基鸟苷的NMR研究

本文采用氢氟酸吡啶鎓在5′-位选择性断裂1,1,3,3-四异丙基二硅氧烷基保护基的方法得到了核苷衍生物N-异丁酰基-3′-O-(1-氟-1,1,3,3-四异丙基-1,3-二硅氧烷-3-基)-2′-苄氧羰基鸟苷(化合物1),并应用液相色谱串联质谱(LC-MS)、气相色谱-高分辨质谱(GC-HRMS)、液体1D和2D NMR谱(包括~1H NMR、^(13)C NMR、19F NMR、DEPT、~1H-~1H COSY、~1H-^(13)C HSQC和~1H-^(13)C HMBC),对产物的~1H、^(13)C和19F NMR信号进行了归属,确定了其结构.

1,3-二苯基-1,1,3,3-四(二甲基硅氧基)二硅氧烷的合成与表征

以苯基三甲氧基硅烷、四甲基二硅氧烷为原料,在固体酸催化下水解缩合,得到1,3-二苯基-1,1,3,3-四(二甲基硅氧基)二硅氧烷含量为42.6%的含氢低聚硅氧烷;再于0.665 kPa真空度下精馏,得到纯度为97.5%的产物。采用IR、GC-MS、1HNMR、13C NMR对其进行结构表征。结果表明,产物的结构特征与1,3-二苯基-1,1,3,3-四(二甲基硅氧基)二硅氧烷完全吻合。

Development of 3-actoxymethoxycarbonyl-2,2,5,5-tetramethyl-1-pyrrolidinyloxyl as an electron paramagnetic resonance imaging reagent for in vivo mapping brain oxygen distribution and infarction in ischemic brain

Measurement of oxygen concentration and distribution in brain is essential to understanding the pathophysiology of stroke. Although brain oxygen level is critical for brain tissue survival,

几种含α-官能团的二硅氧烷的合成与表征

以氯甲基二甲基氯硅烷为原料制备了几种含官能团的二硅氧烷封端剂。将氯甲基二甲基氯硅烷在50%乙醇水溶液中水解,可得到85%收率的1,3-双氯甲基-1,1,3,3-四甲基二硅氧烷(产物Ⅰ);产物Ⅰ同醋酸和三乙胺在对二甲苯中回流18h,得到90%收率的1,3-双乙酰氧甲基-1,1,3,3-四甲基二硅氧烷(产物Ⅱ);在盐酸催化下,产物Ⅱ同过量甲醇在室温下进行酯交换反应24h,得到约80%收率的1,3-双羟甲基-1,1,3,3-四甲基二硅氧烷。用1HNMR、GC-MS、IR、元素分析等方法对产物进行了表征,以确定产物的含量、结构和主要副产物的结构,简单探讨了反应的影响因素。

SYNTHESES AND CHARACTERIZATI0N OF Si-CONTAINING POLYESTER-POLYETHER MULTIBLOCK COPOLYMERS

A series of Si-containing polyester-polyether multiblock copolymers were synthesizedby transesterification and melt copolycondensation of organosilicon monomers [1, 1, 3, 3-tetramethyl-1, 3-bis （p-carbomethoxyphenyl） disiloxane] （I ） or dimethyl bis （p-carbometh-oxyphenyl） silane] （II） and dimethyl terephthalate （DMT）, with 1, 4-butanediol, poly-tetramethylene glycol （PTMG） respectively. The organosilicon monomers were preparedby Grinard reaction, oxidation and esterification. The structures of the above monomers（I）, （II） and the copolymers were characterized by MS anal. and;H-NMR.