硬段含量对聚氨酯弹性体的吸水动力学及力学性能的影响  

Effect of Hard Segment Content on theWater Absorption Dynamic and Mechanical Properties of Polyurethane Elastomer

作　　者：王义霞 梁书恩[2] 宋宁宁 田春蓉[2] 林晓艳[1,3] 陈可平[2] Yi-xia Wang;Shu-en Liang;Ning-ning Song;Chun-rong Tian;Xiao-yan Lin;Ke-ping Chen(School of Materials and Chemistry,Southwest University of Science and Technology,Mianyang 621010;Institute of Chemical Materials,China Academy of Engineering Physics,Mianyang 621900;Engineering Research Center of Biomass Materials,Ministry of Education,Southwest University of Science and Technology,Mianyang 621010)

机构地区：[1]西南科技大学材料与化学学院,绵阳621010 [2]中国工程物理研究院化工材料研究所,绵阳621900 [3]西南科技大学生物质材料教育部工程研究中心,绵阳621010

出　　处：《高分子学报》2023年第2期277-285,共9页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号51903228)资助项目.

摘　　要：合成了硬段含量分别为30 wt%、37 wt%和45 wt%的聚醚型聚氨酯弹性体(PTMG-PU).研究了硬段含量、水浸温度和试样厚度对PTMG-PU吸水动力学的影响.研究结果表明:PTMG-PU在25℃~60℃之间的吸水动力学过程可以用Fick模型进行拟合;扩散系数和平衡吸水率随着硬段含量的增加均呈逐渐降低的趋势,水分子扩散活化能和指前因子均随着硬段含量的增加而增加,说明硬段含量越高,水分子需要克服的传输能垒越高.进一步,吸水导致聚氨酯弹性体的拉伸断裂强度、100%定伸强度和拉伸模量等力学性能出现明显的下降,这不仅是由于水分子与聚氨酯弹性体的软段相发生了增塑作用,而且水分子也与部分硬段相微区发生了作用,导致部分硬段相微区瓦解.Polyether polyurethane elastomers(PTMG-PU)with hard segment contents of 30 wt%,37 wt%and 45 wt%were synthesized.The effects of hard segment content,immersion temperature and sample thickness on the water absorption dynamics of PTMG-PU were studied.The microphase separation structure evolution of PTMG-PU during water absorption was characterized by small Angle X-ray scattering technique.The results show that the dynamic process of water absorption of PTMG-PU between 25 and 60℃can be fitted by Fick’s model.The diffusion coefficient and equilibrium water absorption rate decrease gradually with the increase of hard segment content,but the time required to reach the equilibrium water absorption rate is about 22 h.In addition,the diffusion activation energy and preexponential factor of water molecules increase with the increase of hard segment content,indicating that more energy is needed to overcome the energy barrier transmitted by water molecules in PTMG-PU.Furthermore,the mechanical properties of PTMG-PU,such as tensile strength and tensile modulus,decreased significantly during the process of water absorption,which was not only due to the plasticization of water molecules with the soft phase of polyurethane elastomer,but also due to the interaction of water molecules with some hard microdomains,leading to the disintegration of some hard microdomains.This provides theoretical guidance for the design and development of high-performance PTMG-PU in high humidity environment and theoretical support for the application of PTMG-PU in practical engineering.

关 键 词：聚氨酯弹性体 吸水动力学 力学性能 微相分离结构 

分 类 号：TQ334.1[化学工程—橡胶工业]