光固化薄膜收缩应力的测试方法与演化机制研究  

Measurement and mechanism of the shrinkage stress evolutionfor photopolymerized thin films

作　　者：王琨 鲍磊 薛晓凯 王正直 Kun Wang;Lei Bao;Xiaokai Xue;Zhengzhi Wang(Department of Engineering Mechanics,School of Civil Engineering,Wuhan University,Wuhan 430072,China;Shenzhen Research Institute,Wuhan University,Shenzhen 518052,China)

机构地区：[1]武汉大学土木建筑工程学院工程力学系,武汉430072 [2]武汉大学深圳研究院,深圳518052

出　　处：《科学通报》2025年第4期522-533,共12页Chinese Science Bulletin

基　　金：国家优秀青年科学基金(12422205);国家自然科学基金(12272276);中央高校基本科研业务费专项资金(2042023kf0194);深圳市科技计划(JCYJ20240813111102004)资助。

摘　　要：光固化薄膜广泛应用于表面涂层、黏结剂、生物医疗等领域.然而,光固化过程中因其体积收缩产生的收缩应力会在材料边界和内部产生不利影响,如涂层开裂和黏接部件变形等.因此,准确测量并预测光固化薄膜的收缩应力,进而控制收缩应力至关重要.本文基于悬臂梁测试原理,通过集成光源控制系统、位移控制系统及高精度位移传感系统,搭建了光固化薄膜收缩应力测试平台.基于三维黏弹性理论,发展了预测薄膜材料收缩应力的有限元仿真方法.以典型紫外光固化薄膜为研究对象,系统研究了薄膜样品在不同约束刚度和厚度条件下收缩应力的演化规律.结果表明,本文搭建的测试平台能够精确控制薄膜样品的约束刚度与厚度,并能准确测量多工况收缩应力的动态演化.此外,本文提出的仿真方法能够准确捕捉薄膜材料收缩应力的演化特性.通过对光固化收缩应力的实验与仿真研究,本文为揭示光固化薄膜收缩应力发展的动态机制和优化光固化产物的力学性能提供了向导.Photopolymerized thin films are widely used in surface coatings, adhesives, biomedicine and other applications, thanks totheir incomparable advantages such as rapid reaction, spatial and temporal controllability, and being economical andenvironment-friendly. However, during photopolymerization, the polymerization-induced volumetric shrinkage generatesundesired shrinkage stress within the material and at its interfaces. This undesired shrinkage stress can adversely affect thematerial properties, such as coating cracking and bonded component deformation. Therefore, accurately measuring andpredicting shrinkage stress evolution in photopolymerized thin films are crucial for optimizing material performance andimproving the service life. To address the challenges in the experimental measurement and simulation prediction of theshrinkage stress in thin films, this study developed a real-time shrinkage stress measurement instrument setup based on thecantilever beam theory, integrated with light source and displacement control systems. Additionally, a finite elementmethod based on three-dimensional viscoelastic theory was developed to predict shrinkage stress in thin films accurately.The influence of constraint stiffness and sample thickness on shrinkage stress was systematically investigated usingultraviolet photopolymerized materials, and the accuracy of the finite element method was validated. The results indicatedthat the experimental setup demonstrated its ability to precisely control both the constraint stiffness and the thickness of thesamples, allowing for accurate real-time measurement of shrinkage stress under different conditions. Meanwhile, the finiteelement method could accurately predict shrinkage stress under varying levels of constraint stiffness and film thickness. Itwas observed that shrinkage stress increased with constraint stiffness. However, the increase in shrinkage stress (from0.02621 MPa to 0.74985 MPa, representing a 28.6-fold increase) was much smaller than the increase in constraint stiffness(fr

关 键 词：光固化薄膜 聚合收缩应力 实验方法与仪器 有限元仿真 

分 类 号：TB383.2[一般工业技术—材料科学与工程]