李俊青

摘 要：目的：为了有效提高传统密封胶的拉伸强度、抗弯曲性能和材料硬度，研究脱乳酸乙酯新型有机硅密封胶的制备及其力学性能。方法：以乳酸乙酯为交联剂，利用制备的原料、试剂和仪器，通过计算物料、合成乳酸乙酯、制备有机硅密封胶预聚体等步骤，制备脱乳酸乙酯新型有机硅密封胶试件。在制备的密封胶试件上施加不同方向、不同大小的应力，从拉伸、抗弯曲和硬度3个方面分析制备密封胶的力学性能。结果：与传统密封胶相比，脱乳酸乙酯新型有机硅密封胶的硬度较大，拉伸强度和断裂伸长率分别提高了0.777MPa和331.9%，弯曲量降低至368mm。结论：脱乳酸乙酯新型有机硅密封胶的拉伸强度增大，断裂伸长率提高，弯曲量降低，能够有效提高拉伸强度、抗弯曲性能以及材料硬度。

关键词：乳酸乙酯;有机硅;密封胶;拉伸强度;力学性能

中图分类号：TQ430 文献标识码：A 文章编号：1001-5922（2021）08-0007-06

Study on the Preparation and Mechanical Properties of New Type Organic Silicone Sealant from Ethyl Lactate

Li Junqing

（Tianjin Haoan Safety and Hygiene of Evaluation and Monitoring Co.， Ltd.， Tianjin 300202， China）

Abstract：Objective： In order to effectively improve the tensile strength， bending resistance and material hardness of the traditional sealant， the preparation and mechanical properties of a new type of silicone sealant from ethyl lactate were studied. Methods： Using ethyl lactate as cross-linking agent， using raw materials， reagents and instruments， through calculating materials， synthesizing ethyl lactate， preparing silicone sealant prepolymer and other steps， a new type of silicone sealant was prepared. Stresses of different directions and different magnitudes were applied to the prepared sealant specimens， and the mechanical properties of the prepared sealant were analyzed from three aspects： tensile strength， bending resistance and hardness. Results： Compared with the traditional sealant， the hardness of the new silicone sealant from ethyl lactate was higher， the tensile strength and elongation at break were increased by 0.777MPa and 331.9%， respectively， and the bending amount was reduced to 368mm. Conclusion： The tensile strength of the new silicone sealant from ethyl lactate is increased， the elongation at break is increased， and the bending amount is reduced， which can effectively improve the tensile strength， bending resistance and material hardness.

Key words：ethyl lactate; organic silicon; sealant; tensile strength; mechanical properties;

0 引言

密封膠属于一种用于填补缝隙的材料，在建筑、电子、航空、汽车工业、医疗等多个领域中广泛应用，并取得了良好的应用效果。在诸多类型中，有机硅密封胶由于具有隔音、保温、减振等功能，在耐热与耐寒等方面具有明显优势。因此，其应用范围更广，应用效果更优[1]。按照产品形态和结构可以将有机硅分为单组分和双组分两种类型，利用空气中的水分因子硫化形成弹性硅橡胶。

目前高层建筑行业发展迅速，对密封胶的需求量和质量要求也逐渐增加，为了适应大跨度建筑可能存在的位移变形，需要制备出力学性能更高的有机硅密封胶[2]。……