摘要
为提高羟基聚苯硼硅氧烷的耐热性,以二甲基二氯硅烷(DMDC)与苯硼酸(PBA)为原料,在浓硫酸的催化下合成耐热羟基聚苯硼硅氧烷,研究了单体物质的量比、反应温度对羟基聚苯硼硅氧烷热稳定性的影响。结果表明,当DMDC与PBA物质的量比为10∶1.1、反应温度为120℃时,所得产物质量损失5%时的温度(T_5)为451.2℃、最大分解速率时温度(T_(max))为589.0℃、折射率为1.405 1、相对分子质量为11 920、羟基质量分数为0.260%。利用核磁共振(NMR)、红外光谱(FT-IR)对羟基聚苯硼硅氧烷的结构进行了表征,证实合成了目标产物。四甲氧基硅烷固化的羟基聚苯硼硅氧烷的耐热性提高,T_5为484.0℃。
In order to improve the heat resistance of hydroxypolyphenyl-borosiloxane,it was synthesized by the reaction of PBA and DMDC under the catalysis of sulfuric acid.The effects of monomer molar ratio and reaction temperature on the thermal stability of hydroxypolyphenyl-borosiloxane were investigated.The results showed that when the molar ratio of DMDC to PBA was 10∶1.1 and the reaction temperature was 120 ℃,the hydroxypolyphenyl-borosiloxane's T_5,T_(max), molecular weight,refractive index,and hydroxyl group content were 451.2 ℃,589.0 ℃,11 920,1.405 1,and 0.260%,respectively.The structure of hydroxypolyphenyl-borosiloxane was characterized and proved by NMR and FT-IR.The heat resistance of boron-silicon rubber obtained by curing the polyborosiloxane with tetramethoxysiloxane was higher than that of polyborosiloxane,and the boron-silicon rubber's T_5 was 584.0 ℃.
引文
[1] 来国桥.有机硅产品合成工艺及应用[M].北京:化学工业出版社,2010.
[2] 张玉龙,张晋生.特种橡胶及应用[M].北京:化学工业出版社,2011.
[3] 冯圣玉.有机硅高分子及其应用[M].北京:化学工业出版社,2004.
[4] 谢择民,李其山,王金亭,等.环二硅氨烷化学的研究:Ⅰ主链含环二硅氨烷硅橡胶的合成和性能[J].高分子学报,1979,1(4):215-223.
[5] 韩淑玉,郭建民.国产苯醚撑硅橡胶应用研究[J].特种橡胶制品,1980(2):3-10.
[6] 吴艳金,吴明军,李美江.聚硼硅氧烷的制备及应用研究进展[J].高分子通报,2012(2):94-98.
[7] DESHPANDE G,REZAC M E.The effect of phenyl content on the degradation of poly(dimethyldiphenyl) siloxane copolymers[J].Polymer Degradation and Stability,2001,74(2):363-370.
[8] JOVANOVIC J D,GOVEDARICA M N,DVORNIC P R,et al.The thermogravimetric analysis of some polysiloxanes[J].Polymer Degradation & Stability,1998,61(1):87-93.
[9] LOU P,ZHANG X,LIU B,et al.Synthesis and thermal degradation mechanism of polyorganocarborane-siloxanes containing m-carboranylmethyl unit[J].Polymer Degradation & Stability,2017,144:304-314.
[10] WU C,JIN J,YANG X,et al.Effect of structure and additives on thermal stability of silicone fluids[J].Journal of Applied Polymer Science,2010,117(5):2530-2537.
[11] ZHAO H Y,ZHAO J B,LI H,et al.Preparation and characterization of polyborosiloxanes and their blends with phenolic resin as shapeable ceramic precursors[J].Polymer Degradation & Stability,2014,32(2):187-196.
[12] 姚成,张骥红.羟基硅油中羟基含量的容量法测定[J].化学世界,1998,13(9):491-493.
[13] BARTHOLOMEYZIK T,PENDRILL R,LIHAMMAR R,et al.Kinetics and mechanism of the plladium-catalyzed oxidative arylating carbocyclization of allenynes.[J].Journal of the American Chemical Society,2018,140 (1):298-309
[14] LEE C Y,AHN S J,CHEON C H.Protodeboronation of ortho and para-phenol boronic acids and application to ortho and meta functionalization of phenols using boronic acids as blocking and directing groups[J].The Journal of Organic Chemistry,2013,78(23):12154-12160.
[15] CHEN W,ZENG X,LAI X,et al.Synergistic effect and mechanism of platinum catalyst and nitrogen-containing silane on the thermal stability of silicone rubber[J].Thermochimica Acta,2016,632:1-9.
[16] THOMAS T H,KENDRICK T C.Thermal analysis of polydimethylsiloxanes:I Thermal degradation in controlled atmospheres[J].Journal of Polymer Science Part B Polymer Physics,1969,7(3):537-549.
[17] RODE V V,VERKHOTIN M A,RAFIKOV S R.Some aspects of thermal degradation and stabilization of polydimethylsiloxane[J].European Polymer Journal,1969,5(S):401-416.