【作者】 刘欣；

【导师】 徐建中； 屈红强；

【作者基本信息】 河北大学 ， 应用化学， 2014， 硕士

【摘要】 聚对苯二甲酸丁二醇酯（PBT）是一种应用广泛的工程塑料，主要应用于电子、机械、汽车等领域。PBT本身易于燃烧，难于成炭，且燃烧时连续滴落，易使火焰蔓延引起火灾，这就要求对PBT进行有效的阻燃改性，满足生产和生活的需要。本文主要合成了次磷酸盐阻燃剂，并将其应用到PBT中，通过热重分析（TG-DTG）、热重-红外联用（TG-FTIR）、热重-质谱联用（TG-MS）、锥形量热等分析手段对阻燃前后PBT的热降解机理进行了深入的研究。具体内容如下：第一部分，利用共沉淀法合成了Al(H2PO2)3（AHP）、 La(H2PO2)3·H2O和Ce(H2PO2)3·H2O，运用红外（FTIR）、X射线衍射仪（XRD）、能量色散谱仪（EDS）、扫描电镜（SEM）对产物进行表征，之后通过TG-DTG、TG-FTIR和TG-MS研究了其降解过程和降解产物，并对降解过程进行了动力学研究。第二部分，将合成的Al(H2PO2)3、La(H2PO2)3和Ce(H2PO2)3添加到PBT中，研究了其对PBT的阻燃性能、热分解行为的影响，并通过TG-MS探讨了阻燃机理。结果表明：当次磷酸盐用量为25%时，阻燃PBT的极限氧指数（LOI）提高了7%~8%，添加La(H2PO2)3和Al(H2PO2)3的PBT的垂直燃烧等级分别达到UL-94V-0和V-1级；另外，Al(H2PO2)3的加入提高了阻燃样品的成炭率；其分解生成的焦磷酸铝在样品表面形成一层液态保护膜，阻止可燃气体进入气相。第三部分，将Al(H2PO2)3和Trimer添加到PBT中，以极限氧指数（LOI）、垂直燃烧测试、锥形量热分析研究了阻燃PBT的燃烧性能。锥形量热分析结果表明PBT/AHP/Trimer展示出良好的消烟性能。通过TG-FTIR、TG-MS研究阻燃PBT的降解过程。AHP和Trimer加入，降低了样品的起始分解温度（T-5%），但促进了残炭的生成。PBT、 PBT/25%AHP和PBT/AHP/Trimer的气相降解产物CO2和丁二烯，而PBT/AHP/Trimer产生更少量的CO2和丁二烯，生成更多的残炭。PBT/25%AHP的PO·自由基的含量是PBT/AHP/Trimer的1.3倍，这表明AHP单独使用表现出较强的气相阻燃作用。更多还原

【Abstract】 Poly (1,4-butylene terephthalate)(PBT) is a widely used engineering plastics, mainlyused in electronics, machinery, automobile and other fields. Nevertheless, its flammability andserious dripping during combustion limited its potential applications. It is necessary to modifyPBT in order to meet the requirements of industrial and life technology. In this paper, we haveprepared hypophosphite, and they were added to PBT as flame retardants. Subsequently,thermal degradation properties of PBT with additives were investigated by using TGA-DTG,TGA-FTIR, TGA-MS and cone calorimeter. More details are as follow:Firstly, Aluminum hypophosphite, lanthanum hypophosphite monohydrate and ceriumhypophosphite monohydrate were synthesized, and characterized through X-ray diffraction(XRD), energy dispersive spectrometer (EDS) and scanning electron microscopy (SEM). Thedegradation process and degradation produats were studied by TG-DTG、 TG-FTIR andTG-MS, and study on the dynamics of degradation process.Secondly, the fire retardant effect, thermal stability and mechanical properties of PBTsystem containing hypophosphite were discussed. The LOI of flame-retardant PBT increasedabout7-8%when25wt%hypophosphite was introduced into PBT. UL-94rating V-1and V-0were respectively obtained when aluminum hypophosphite and lanthanum hypophosphitewere introduced into PBT at a total loading of25wt%. The hypophosphite can promote PBTto form more stable char layers and reduce the amount of released gas.Thirdly, flame-retarded PBT has been prepared using aluminum hypophosphite (AHP)and Trimer. The combustion properties of flame-retarded PBT were evaluated using LOI,UL-94and cone calorimetry. The cone calorimeter data indicated that the presencePBT/AHP/Trimer imported a significant smoke-suppressing effect. The thermal degradationproperties of flame-retarded PBT were also investigated using TG-FTIR and TG-MS. Theresults showed that addition of AHP and Trimer, not only decreased T-5%(defned as thetemperature at which5%of the initial weight has been lost), but also promoted stability of thechar residue. For the samples of PBT, PBT/25%AHP and PBT/AHP/Trimer, the main gas pyrolysis products were CO2and butadiene, while the sample of PBT/AHP/Trimer generatedless CO2and butadiene, and consequently retained more carbon in the matrix. The amount ofphosphorus-oxygen radicals of PBT/25%AHP was1.3times that of PBT/AHP/Trimer, whichindicated that AHP alone showed slightly stronger gaseous phase effect than the combinationofAHP and Trimer.更多还原