聚氨酯防水透湿涂层剂的合成

以聚丙二醇(PPG)/聚乙二醇(PEG)混合多元醇作为聚醚二醇组分,与二苯基甲烷二异氰酸酯(MDI)进行预聚,然后用1,4-丁二醇扩链合成有防水透湿性的聚氨酯涂层剂,经红外光谱分析确定为目标产物。研究了不同的工艺条件对涂层剂合成的影响,讨论了R值〔n(—NCO)/n(—OH)〕对涂层剂黏度的影响。结果表明,n(MDI)∶n(聚醚二醇)=1.42∶1,反应温度82℃,预聚反应时间1h,扩链反应时间2h,R值为1.02～1.07时,制得的涂层剂耐静水压值达到20.4kPa,透湿量达到4533g/(m2·d)。经与比利时UCB公司的产品UCcoat2000和日本Toray公司的产品EntrantGⅡTX进行比较,本涂层剂耐静水压和透湿量指标更优越。

Synthesis of Moisture-permeable Waterproof Polyurethane Coating

The polyurethane(PU) coating agent was synthesized by prepolymerizing polypropylene glycol(PPG)/polyethylene glycol(PEG) mixed polyether diol and 4,4,-diphenylmethane diisocyanate(MDI) and then reacting with the chain extender 1,4-butanediol.The product was identified by IR.Effects of technological conditions on the synthesis process and the value of R〔n(—NCO)/n(—OH)〕 on the viscosity of the PU coating agent were discussed.The results indicate that when n(MDI)∶n(polyether diol)=1.42∶1,the reaction temperature is 82 ℃,the prepolymerization time is 1 h,the chain-extending reaction time is 2 h,and the value of R is between 1.02~1.07, a kind of PU coating with water pressure resistance of 20.4 kPa and moisture permeability of 4533 g/(m2·d) is obtained.Compared with like products UC coat 2000 of UCB company(Belgium) and Entrant GⅡ-TX of Toray company(Japan),the water pressure resistance and moisture permeability of the synthesized polyurethane coating agent are ascendant.