【作者】 刘青宝；

【导师】 李殿卿； 林彦军；

【作者基本信息】 北京化工大学 ， 应用化学， 2009， 硕士

【摘要】 聚氯乙稀（PVC）树脂是一种应用广泛的热塑性塑料,但其热稳定性很差,必须加入一定数量的热稳定剂以提高其热稳定性。目前使用的热稳定剂主要以铅盐类、有机锡类等为主,由于其含有重金属,能够对人类健康造成长期的危害。鉴于有毒热稳定剂产生的危害,开展无毒、无污染、复合和高效的PVC热稳定剂研究具有十分重要的意义。乙酰丙酮类化合物含β-二酮结构,可以通过与PVC进行烷基化反应迅速置换PVC加工期间生成的烯丙基氯,使共轭烯烃的分子链中断、变短,起到良好的热稳定作用,在改善PVC制品的初期着色性方面具有优异的效果,同时可以与多种热稳定剂产生协同作用。本论文采用直接转化沉淀法成功合成了乙酰丙酮锌、乙酰丙酮钙、乙酰丙酮镁、乙酰丙酮铝四种化合物,克服了乙酰丙酮金属化合物传统合成方法产率低、使用大量有机溶剂和操作过程复杂等缺点。通过红外、元素分析、热重、XRD和激光粒度进行了分析表征,结果表明产物晶体结构完整,收率达90%以上。通过静态热老化实验、刚果红实验、色差测试等研究发现,制备的乙酰丙酮锌能够很好地改善PVC的初期稳定性能,乙酰丙酮钙能够显著延长PVC的长期热稳定时间,乙酰丙酮镁和乙酰丙酮铝也对PVC具有一定的热稳定作用。随着乙酰丙酮锌添加量的增加,PVC的初期着色性得到进一步改善,但过量的Zn含量会引起“锌烧”现象,降低PVC的长期热稳定性能。随乙酰丙酮钙、乙酰丙酮镁和乙酰丙酮铝添加量的增加,PVC的长期稳定性均得到提高,尤其是乙酰丙酮钙,在100 phr PVC中添加4 phr,在200±1℃环境下,可以使PVC的热稳定时间达到83 min以上。通过力学性能测试表明,乙酰丙酮锌、乙酰丙酮钙、乙酰丙酮镁对PVC均具有增强和增韧的效果。考察了乙酰丙酮锌与乙酰丙酮钙复配的二元热稳定剂体系对PVC的热稳定效果,随着乙酰丙酮锌添加量的增加,PVC初期着色性能得到改善,但是由于“锌烧”现象,使PVC的长期热稳定性能下降。乙酰丙酮锌与乙酰丙酮钙最佳比例分别为1/19,PVC的热稳定时间为80 min。研究了乙酰丙酮锌-乙酰丙酮钙-LDHs（ZnMgAl-CO₃-LDHs）复配的三元体系对PVC的热稳定作用,当100 phr PVC中Zn（acac）₂的添加量为0.2 phr,且Ca（acac）₂/LDHs的比值为1/2时,三元热稳定体系中各组分发挥了明显的协同作用,对PVC的热稳定作用最佳,热稳定时间达到了90min。更多还原

【Abstract】 Polyvinylchloride（PVC） resins are a type of thermoplastic that have a wide variety of applications.However their thermal stability is very poor and addition of one or more stabilizers is required during processing.The main classes of thermal stabilizers in current use are lead salts and organo-tin compounds.These all have disadvantages in terms of toxicity,environmental pollution and/or high cost.As a result of the worldwide increase in environmental awareness and the increasingly stringent limits on the use of heavy metals,attention is currently being focused on thermal stabilizers that are non-toxic and environmentally-friendly,as well as being economical.Acetylacetone compounds containingβ-diketone structure can replace allyl chloride generated during the machining process through alkylation with PVC which makes Molecular chain of conjugated alkenes fracture.And acetylacetone compounds have good long-term stabilizing effect on PVC and have the effect of improving the resistance of PVC to early color.It also can have a synergetic effect with many other thermal stabilizers on the stability of PVC.In this dissertation,we prepared acetylacetonate Zinc, acetylacetonate Calcium,acetylacetonate Magnesium,acetylacetonate Aluminium in a direct precipitation transfer method,which avoided the defect of low production rate,using large amount of organic solvent of tranditional methods.The characterization of IR,elemental anlysis, TG-DTA,XRD and particle size analysis showed that the production have complete crystal form,single structure.Static aging test,Congo red experiments,Chromatic aberration test showed that the acetylacetonate zinc can greatly improve the early colour of PVC,acetylacetonte Calcium can prolong the long stability of PVC,as well as acetylaceonte Magnesium and acetylacetonate Aluminium.As the increase of acetylacetonate Zinc,the early colour of PVC was improved greatly,however,the excess of Zn may cause "Zinc buring",which decreased the long term stability of PVC.As the increase of acetylacetonate Calcium,acetylacetonte Magnesium and acetylacetonate Aluminium,the long stability of PVC increased greatly, espically acetylacetonate Calcium,by adding 4 phr in 100 phr PVC,can increase the thermal stability of PVC to 83 mins in 200±1℃.The mechanical stability of PVC was increased by addition of、acetylacetonate Calcium,acetylacetonte Magnesium The acetylacetonate Zinc and acetylacetonate Calcium composite to the thermal stability of PVC is studied,as the addition of acetylacetonate Zinc increased,the early colour of PVC was improved,however due to the "Zinc buring" effect,the long-term stabilizing effect was decreased. The optimized ratio between acetylacetonate Zinc and acetylacetonate Calcium is 1/19,in which the PVC stability time is 80 min.The thermal stability effect of acetylacetonate Zinc-acetylacetonate Calcium-LDHs（MgZnAl-LDHs） composite to PVC was studied,when the addition of Zn（acac）₂ is 0.2 phr in 100 phr PVC,and the ratio between Ca（acac）₂/LDHs is 1/2,the composite has obvious synerect effect,which has the best stability effect to PVC,the stability time is 90 min.更多还原