聚酰亚胺改性酚醛泡沫

POLYIMIDE MODIFIED PHENOLIC FOAM

介绍了聚酰亚胺(PI)与酚醛树脂的共混改性方法,同时探讨了聚乙二醇(PEG)的加入对酚醛/聚酰亚胺复合体系的性能影响.结果显示经聚酰亚胺改性后,酚醛复合材料形成了网络互穿结构,其热稳定性、压缩强度以及隔热性能均有明显提高,粉化率、吸水率也有所降低,但仍然具有较高的脆性.在酚醛/聚酰亚胺复合体系中适当的加入聚乙二醇后,材料的脆性得到改善,然而其它性能如压缩强度、热稳定性和隔热性却比加入前有所降低.通过研究发现,为了改善酚醛泡沫塑料总体性能,聚酰亚胺和聚乙二醇的最佳用量均为3%～5%.

To overcome the shortcomings of pure phenolic resin,such as high brittleness and easy pulverization,the blending modification of phenolic resin with polyimide was introduced.Polyethylene glycol was also added into the phenolic/polyimide composite to investigate its influence on the composite properties.The composites were characterized by FTIR,TG and HRTEM.The peak of C—O stretching vibration(1008 cm-1) becomes weaker in phenolic/polyimide composite than that in neat phenolic resin which means that hydrogen bonds form between PI and PF polymer molecules.From the HRTEM morphologies,the formation of interpenetrating networks in phenolic resin composite could be observed.The modified phenolic resin by polyimide shows obvious improvement in thermal stability,compression strength and thermal insulation properties.The chalking rate and water absorption are also reduced.However,the brittleness of the phenolic/polyimide composite still remains high.The addition of polyethylene glycol into the phenolic/polyimide composite can well resolved this problem.The brittleness of the phenolic/polyimide composite system got better while the other properties such as the compression strength,thermal stability and thermal insulation became worse.From the study we could draw a conclusion that the optimum addition quantities of polyimide and polyethylene glycol are 3% to 5% for the improvement of the overall performance of phenolic foam plastic which makes such material meet the criterion for ship standard.