扩链剂对PU-RIM材料结构和性能的影响研究

Effect of Different Chain Extenders on Structure and Properties of PU-RIM Materials

采用高活性聚醚多元醇与改性MDI为主原料,分别加入扩链剂4,4'-二氨基-3,3'-二乙基-二苯基甲烷(MOEA)、4,4-亚甲基双(3-氯-2,6-二乙基苯胺)(M-CDEA)、1,4-丁二醇(BDO)、乙二醇(EG)、3-羟乙基氧乙基-1-羟乙基苯二醚(HER-L)或聚天门冬氨酸酯(PAE),经反应注射成型工艺制备了6种聚氨酯材料样片。通过红外光谱分析和动态力学热分析等方法,比较了不同扩链剂对材料氢键化、微观相分离、热变形温度和拉伸性能的影响。结果表明:脲羰基比氨酯羰基易于氢键化;加入MOEA和BDO的材料的氨酯羰基氢键化程度相对较低;材料在70℃下的储能模量能够较好的反映热松弛行为; M-CDEA制备的材料微观相分离最好,tanδ较低,热变形温度(HDT)较高,拉伸性能较好; HER-L制备的材料微观相分离最差。

Using high active polyether polyol and modified MDI as raw materials,six different chain extenders including MOEA,M-CDEA,BDO,EG,HER-L and PAE were added,and 6 kinds of polyurethane(PU)samples were prepared by reaction injection molding process.The effects of different chain extenders on the hydrogen bonding and micro phase separation were compared by IR and dynamic mechanical thermal analysis,and the effects of the structure characteristics of the aggregates on the thermal relaxation behavior and tensile stress and strain beha-vior of the materials were studied.The results showed that the hydrogen bonding tendency of urea carbonyl was stronger than that of urethane carbonyl.The degree of carbonyl hydrogen bonding of the MOEA based and BDO based PU was relatively low.E′70℃could reflect the thermal relaxation behavior.The M-CDEA based PU had the best micro phase separation,lower tanδ,higher HDT and better tensile properties.The HER-L based PU had the lowest microscopic phase separation.