芳香族聚噁二唑的成环控制及其阻燃纤维的制备

项目名称： 芳香族聚噁二唑的成环控制及其阻燃纤维的制备

项目编号： No.50873061

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 徐建军

作者单位： 四川大学

项目金额： 35万元

中文摘要： 从分子设计角度出发，对传统芳香族聚噁二唑(POD)分子结构中引入含磷、含溴单体，成功制备出阻燃性能良好的纤维；引入芳醚键的POD可溶解于氯仿、四氢呋喃和DMF等有机溶剂中，改善了POD的加工性。通过正交试验确定了"一步三阶段"法，以制备具有一定分子量p-POD和p/m-POD聚合物和良好加工性能的纺丝原液。对纺丝工艺的探讨表明在硫酸浓度为45％左右，凝固温度约50℃#65292;凝固时间大于8s时，可得到结构和力学性能较好的p-POD纤维。酰肼向噁二唑环转变过程中，通过两种途径转变为过渡态的顺式烯醇结构，然后进行羟基间脱水，形成噁二唑环。含磷阻燃POD热分解后的残碳率较p-POD提高，分解速率降低，单位质量的热释放量降低，热释放温度前移，具有固相阻燃特征，也有气相阻燃效果。在热氧老化过程，除了分子结构产生变化，还存在结晶、交联等现象，POD纤维酰肼弱节减少，能延缓强度和伸长率的损失。p-POD的紫外老化实质是光氧老化,可采用调节分子链共轭程度、隔绝紫外辐射及隔绝氧气对p-POD纤维进行紫外防护。p-POD纤维浸泡在酸溶液下会导致分子结构、聚集态结构和力学性能的变化，可采用加入第三单体和表面氟化改善

中文关键词： 芳香族聚噁二唑（POD）；纤维；阻燃；成环；老化

英文摘要： Two kinds of flameretardant fibers were prepared by adding monomers containing the element P or Br to molecular structure of POD from the aspect of molecular design.POD with arylene ether bonds was soluble in organic solvents such as chloroform,THF and DMF.One-step with three-stages method was developed for preparing p-POD and p/m-POD of certain molecular weight and easier processing spinning solution.P-POD fibers with good structure and mechanical property can be obtained by 45% concentration sulphuric acid whose temperature is 50℃as coagulating bath and the coagulating time is more than 8 seconds.The mechanism on the cyclodehydration of the hydrazide indicated that there was an cis enol transition state in the hydrazide linkage,then dehydration between hydroxyl occurred.The char residuals of POD fibers with P after combustion was higher than that of the usual p-POD fibers, and the rate of heat release during decomposition was also lower than that of p-POD,the mechanism of POD with P flame resistance was solid phase mechanism and accopanied with gas phase mechanism.Besides the chain structure,there were crystallization and crosslinking during the thermal decomposition.Ruducing the hydrazide could slow down the loss of fibers' strength and elongation.The process of p-POD's UV aging was photooxidation aging.UV protection can be taken through accommdating the conjugate chain length,isolating from the UV radiation or oxygen. Acid solutions can affect the molecular structure,state of aggregation and mechanical property.The acid resistance of p-POD fibers can be improved by adding other monomers and fluorination.

英文关键词： Aromatic poly(l;3;4-oxadiazole)s (PODs)；Fiber；Flameretardant；Cyclization；Aging