Wahdat Hares, Elzière Paul, Chan Nicky, Crosby Alfred J
Polymer Science and Engineering Department, University of Massachusetts Amherst, 120 Governors Drive, Amherst, MA 01003, USA.
Saint-Gobain Research North America, 9 Goddard Road, Northborough, MA 01532, USA.
Soft Matter. 2021 Jun 9;17(22):5540-5547. doi: 10.1039/d1sm00089f.
Closed annular adhesive interfaces are commonly found in nature as well as in many existing and developing technologies. Such contacts provide enhanced control of interfacial history by prescribing whether interfacial separation occurs at the outer or inner edge, and whether internal pressure affects the required force for separation. To facilitate the development of technologies involving annular contacts, we have experimentally measured the relationship between applied displacement, resulting force and internal pressure, and annular interface dimensions for the contact between a rigid annular probe and an adhesive layer with finite thickness. Experiments were validated by finite element analysis models, which were used to develop semi-empirical analytical relationships for the changes in contact compliance as a function of material properties and geometric constraints. Additionally, the change in internal pressure was modeled as a function of annular contact dimensions and adhesive layer material properties. This model predicts the critical volume where internal pressure changes alters critical force for separating an annular contact interface. The results discussed here provide a foundation for new experimental protocols for characterizing soft materials, including pressure-sensitive adhesives, as well as guidelines for designing annular interfacial materials with controlled separation histories.
封闭环形粘合界面在自然界以及许多现有和正在发展的技术中普遍存在。这种接触通过规定界面分离是发生在外边缘还是内边缘，以及内部压力是否影响分离所需的力，从而提供了对界面历史的增强控制。为了促进涉及环形接触的技术发展，我们通过实验测量了施加位移、合力与内部压力之间的关系，以及刚性环形探针与具有有限厚度的粘合层之间接触的环形界面尺寸。实验通过有限元分析模型进行了验证，该模型用于建立接触顺应性变化与材料特性和几何约束之间的半经验分析关系。此外，内部压力的变化被建模为环形接触尺寸和粘合层材料特性的函数。该模型预测了内部压力变化改变分离环形接触界面临界力的临界体积。这里讨论的结果为表征包括压敏粘合剂在内的软材料的新实验方案提供了基础，同时也为设计具有可控分离历史的环形界面材料提供了指导方针。
