无卤阻燃聚乙烯醇缩甲醛纤维的制备与表征

摘要

A kind of intumescent halogen-free flame retardant, bisneopentyl glycol dithiopyrophosphate (BGDTP) , was synthesized by one-step method via using neopentyl glycol and thiophosphoryl chloride as raw materials. The structure of BGDTP was characterized by Fourier transform infrared spectrometry (FTIR) and 1H neclear magnetic resonnance spectrometry (1H NMR). A flame retardant polyvinyl formal (PVFM) fiber was prepared by blend spinning process using BGDTP as flame retardant and polyvinyl alcohol (PVA) as the fiber matrix. The mechanical properties, flame retardancy and thermal properties of flame retardant PVFM fiber were characterized. The results showed that one-step method yielded 82% BGDTP; the limiting oxygen index (LOI), the temperature corresponding to the maximum degradation rate at high temperatures and char residue were all increased, but the breaking strength of PVFM fiber was slightly decreased as the amount of BGDTP was increased in the fiber; the flame retardant PVFM fiber with w( BGDTP) of 20% had the LOI of 30. 8% , the breaking strength 5.42 cN/dtex and the maximum degradation temperature and char residue greatly increased as compared with pure PVFM fiber, and formed a continuous, compact and swelling char layer after burning.%以新戊二醇和三氯硫磷为原料,一步法合成了无卤膨胀型阻燃剂二硫代焦磷酸双新戊二醇酯( BGDTP)；采用傅里叶变换红外光谱(FTIR)、核磁共振氢谱(1H-NMR)对BGDTP的结构进行了表征.将BGDTP 添加到聚乙烯醇(PVA)中进行共混纺丝,制备了阻燃聚乙烯醇缩甲醛(PVFM)纤维,并对其力学性能、阻燃性能和热性能进行了表征.结果表明:一步法合成BGDTP的收率为82％；随着纤维中BGDTP添加量的增加,PVFM纤维的极限氧指数(LOI)、高温下的最大分解速率温度和残炭量均增大,但其断裂强度略有下降；当w(BGDTP)为20％时,阻燃PVFM纤维的LOI为30.8％,断裂强度为5.42 cN/dtex,最大热分解温度和残炭率比纯PVFM纤维均有较大幅度增加,燃烧形成连续致密的膨胀炭层.