硅烷偶联剂改性水镁石及其在EVM中的应用

Modification of Brucite by Silane Coupling Agent and Its Application in EVM

采用γ-氨丙基三乙氧基硅烷(KH550)及γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH570)对水镁石进行表面改性,并作为阻燃剂添加到乙烯-乙酸乙烯酯橡胶(EVM)中,制备了改性水镁石阻燃EVM复合材料。研究表明,KH550和KH570改性水镁石的添加均可以提高EVM的极限氧指数(LOI)和垂直燃烧级别,相比于未改性水镁石阻燃EVM复合材料,当KH550和KH570改性水镁石的质量分数为64.0%时,改性水镁石阻燃EVM复合材料的LOI由28.0%分别提高到39.4%和43.4%,并通过UL94 V-0级,其断裂伸长率由827.0%分别下降到410.0%和393.0%,而拉伸强度由4.0 MPa分别提高到6.6 MPa和5.9 MPa。KH570和KH550相比,前者改性水镁石阻燃EVM可以获得更好的阻燃效果,而后者改性水镁石阻燃EVM可以保持更高的断裂伸长率及拉伸强度。

The brucite was surface-treated with 3-aminopropyhriethoxysilane （ KH550 ） and 3-（methacryloyloxy） propyhrimethoxysilane （KH570）. Then it was filled into ethylene-vinyl acetate rubber （EVM） as a kind of flame retardant to prepared the brucite modified flame-retardant EVM composite. The results show that the addition of the brucite treated with KH550 or KH570 can improve the limiting oxygen index （LOI） value and the UL94 ratings of the EVM composites obviously. With the addition of 64% brucites treated with KH550 or KH570 in EVM, the LOI value of the EVM composite rises from 28.0% to 39.4% and 43.4% respectively with UL94 rating of V-O level, the elongation at break of the EVM compos decreases from 827.0% to 410. 0% and 393.0% respectively, and the tensile strength increases from 4 te 0 MPa to 6. 6 MPa and 5.9 MPa respectively. By comparing brucites treated with KH550 or KH570, it is found that the former shows better flame-retardant effect, while the latter ensures higher elongation at break and tensile strength of the composite.