摘要
聚苯撑苯并二噁唑(PBO)纤维具有超高强度和模量、优异的耐热性和阻燃性,是一种在国防军工、航空航天等领域有重要应用价值的有机高性能纤维。本文综述了国内外PBO纤维的发展历程、纤维的性能,重点介绍了制备高分子量PBO聚合物和纺制高性能PBO纤维的关键技术和先进工艺,提供了改善PBO纤维界面粘结性能、压缩性能和光老化稳定性能的不同技术途径。结果表明:PBO聚合只有多种因素包括单体、工艺、设备等同时优化才能获得高分子量的PBO聚合物,利用双螺杆挤出机同时完成聚合和液晶纺丝成型是工业化连续生产高性能PBO纤维的先进技术路线;通过在PBO大分子链上引入离子基团或双羟基能显著提高PBO纤维与环氧树脂的界面粘结强度,双羟基的存在能使PBO大分子链间建立氢建相互作用从而也提高了PBO纤维的压缩性能,双羟基单体特有的紫外吸收性能更是有效地改善了PBO纤维的光稳定性;在PBO聚合时添加光吸收剂,或在PBO纤维表面涂覆聚酰亚胺都是改善PBO纤维光稳定性的有效方法。
Polybenzoxazole （PBO） fiber with extraordinary high strength, modulus, excellent heat stability and flame resistance has received great attention as one of competitive candidates applied in the field of national defense and aerospace. In this article, the preparation of PBO polymer with high molecular weight, the technique to spin high performance PBO fiber were studied; and the property improvement of PBO fiber, including the interface strength, ultraviolet stability and compressive strength were investigated. The development history of PBO fiber was also shortly reviewed. We found that only under the optimization of monomers, processing and equipments could PBO polymer with high molecular weight be obtained; high performance PBO fiber could be spun by crystalline spinning through twin screw extruder which is also the polymerization reactor at the same time. It was also found that the chemically incorporation of the third monomer containing ionic groups or dihydroxy groups into PBO chains could greatly improve the interfacial shear strength with epoxy resin; and the compressive strength of PBO fiber could also be raised owing to the hydrogen bonds between PBO macromoleculars occurred between dihydroxy groups and nitrogens in benzobisoxazole rings of PBO chains; moreover the third monomer containing dihydroxy groups possesses the ability to absorb ultraviolet light, which makes modified PBO fiber more resistance to ultraviolet exposure. In addition, the loading of some ultraviolet absorbents during polymerization and the coating of soluble polyimides on PBO fiber surface are also effective mothods to improve the ultraviolet stability.
出处
《高分子通报》
CAS
CSCD
北大核心
2013年第10期60-70,共11页
Polymer Bulletin
基金
国家自然科学基金(50673017)
新世纪优秀人才计划(NCET-04-0417)
教育部科技创新重大项目培育资金(705016)
