中文关键词：
2,4–二甲基咪唑;;聚氨酯;;预聚体;;封闭;;固化剂;;拉伸性能
中文摘要：
以聚酯二元醇和二苯基甲烷二异氰酸酯为原料,首先合成聚氨酯(PUR)预聚体,然后以2,4–二甲基咪唑为封闭剂,在催化剂二月桂酸二丁基锡的催化下,制得封闭型聚氨酯(BPUR)。利用傅立叶变换红外光谱(FTIR)仪和差示扫描量热(DSC)仪分别检测封闭结果和解封温度,并对BPUR进行基本性能检测,比较固化剂种类、固化温度、封闭率对BPUR拉伸性能的影响。FTIR谱图显示,2,4–二甲基咪唑对合成的PUR预聚体封闭成功,DSC曲线显示,BPUR的解封温度为100.7℃,BPUR的储存稳定性良好,常温下暴露在空气中可以存放60天以上,基本满足工业存储和生产操作应用。扫描电子显微镜照片显示,BPUR表面无气泡,固化后的BPUR可以有效避免气泡对拉伸性能的影响,拉伸性能优于未封闭的PUR,以二甲硫基甲苯二胺为固化剂,封闭率为60%时,BPUR在140℃固化8 h后的拉伸强度最高,达34.98 MPa。
英文篇名：
Preparation and Properties of 2,4-dimethylimidazole Blocked Polyurethane
英文作者：
Wu Qiong;Peng Jin;Zou Wenjun;Song Xudong;Miao Xie;School of Material Science and Engineering, Henan University of Technology;
英文摘要：
Using polyester diol and diphenylmethane diisocyanate as raw materials,a polyurethane (PUR) prepolymer was first synthesized,and then 2,4-dimethylimidazole was used as a blocking agent to produce a blocked polyurethane (BPUR) under the catalyst of dibutyltin dilaurate.Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) were used to analysis the blocking result and the unsealing temperature,respectively,and the basic properties of the BPUR were tested.The effects of the type of curing agent,curing temperature and blocking rate on the tensile properties of BPUR were compared.The FTIR spectrum shows that 2,4-dimethylimidazole successfully blocks the synthesized PUR prepolymer.The DSC curve shows that the unsealing temperature of BPUR is 100.7℃,and the storage stability of BPUR is good.The BPUR can be stored for more than 60 days when exposed to the air and basically suitable for industrial storage and production operations.Scanning electron microscope photo shows that no bubbles on the surface of BPUR,the cured BPUR can effectively avoid the influence of bubbles on tensile properties.The tensile properties of BPUR are better than unblocked PUR.The dimethylthiotoluenediamine is used as curing agent,BPUR with a closure rate of 60% has the highest tensile strength after curing at 140℃for 8 h,reaching 34.98 MPa.
英文关键词：
2,4-dimethylimidazole;;polyurethane;;prepolymer;;blocking;;hardener;;tensile property
