衣康酸氨化对聚丙烯腈基碳纤维聚合和原丝性能的影响分析

Effect of Aminated Itaconic Acid on the Properties of Polyacrylonitrile Based Carbon Fiber Precursor

为制备力学性能优异的聚丙烯腈基碳纤维,采用氨化度不同的衣康酸(IA)单体与丙烯腈(AN)、丙烯酸甲酯(MA)和乙烯磺酸(AS)制备聚丙烯腈(PAN)基碳纤维。通过聚合转化率的测定表征聚合反应速度,显微镜观察原丝断面形貌,广角X射线衍射表征原丝结晶取向度,动态热机械法表征原丝的玻璃化转变温度和热收缩率,电子万能试验机表征原丝及碳纤维的力学性能。测试结果表明,IA经氨化后制备得到β-衣康酸铵,以β-衣康酸铵作为共聚单体制备的PAN纺丝液的数均相对分子质量达到64100,相对分子质量分布指数为2.96,比粘为1.86;纺丝后原丝断面明亮整齐,氨化度为25%的原丝在12倍牵伸下,单丝拉伸强度为6.8cN/dtex,弹性模量为113.0cN/dtex;该原丝的玻璃化转变温度较未氨化原丝提高了3.19℃;该原丝经炭化后的碳纤维(1K)的拉伸强度达到4572 MPa,弹性模量249GPa,钩结强力62.4N,纤维的力学性能和韧性得到提高。

Itaconic acid(IA)modified with different amounts of ammonia was copolymerized with acrylonitrile(AN),methyl acrylate(MA)and vinyl sulfonic acid(AS).The polymer solution was wet spined to prepare the precursor,then was carbonized to prepare the polyacrylonitrile(PAN)based carbon fiber(CF).The reaction rate,sectional morphology,orientation,glass transition temperature,thermal shrinkage and mechanical behavior of the precursor or CF were studied by the conversion measure,optical microscope,X-ray photoelectron spectroscopy(XPS),dynamic mechanical analyzer(DMA)and electronic tensile testing machine.For experimental results:IA is ammoniated to prepare theβ-ammonium itaconate.The number average molecular,molecular weight distribution and contrast viscosity of the ammoniating PAN dope are about 64100,2.98and1.86 respectively.The sectional morphology of the PAN precursor polymerized withβ-ammonium itaconate is bright and perfect.The tensile strength and elastic modulus of the single precursor with 25%β-ammonium itaconate are about 6.8cN/dtex and 113.0cN/dtex respectively under the drafting rate of 12.The glass transition temperature of the precursor with 25%ammonification increases by 3.19℃.The tensile strength,elastic modulus and loop tenacity of CF(1K)prepared with the precursor are about 4572 MPa,249GPa and 62.4Nrespectively.