丙烯酸酯型端羟基聚醚双固化粘合剂的合成及打印成型固化机理

Synthesis and 3D printing curing mechanism of acrylate hydroxy-terminated polyether photothermal dual-curing adhesive

摘要:

传统的光固化或热固化粘合剂难以满足火炸药打印成型的需求,近年来兴起的光-热双固化策略是火炸药领域的热点研究方向。本文以光-热双固化反应为策略,通过阳离子开环聚合机理,设计并合成了具备快速固化成形和短时间内完全固化特征的新型丙烯酸酯型端羟基聚醚粘合剂,所得目标粘合剂具有较低的粘度和较为优异的低温力学性能。此外,确定了光-热双固化体系最佳的固化工艺参数和较优的物料配比,且对得到的光-热双固化弹性体的力学性能、热稳定性及拉伸性等特性进行了考察,实验结果表明：目标MAPTHF基粘合体系可在紫外光照下5 s内快速固化,在加热3 h内实现完全固化,且MAPTHF基光-热双固化形成的弹性体胶片的拉伸强度为3.15 MPa、延伸率为350%,相比于单独光固化、热固化形成的弹性体胶片具有更为优异的力学性能。目标粘合剂无论从热力学性能还是黏度都满足打印成型工艺的需求并通过了3D打印实验验证。该类光热双固化粘合剂解决了传统光固化3D打印固化速度较慢和短时间内固化不完全的问题,为推进3D打印在火炸药配方中的应用提供支撑,也为解决传统火炸药药柱成型工艺难以实现精密快速成型和性能精准调控奠定了坚实的基础。关键词：光-热双固化粘合剂；火炸药；打印成型工艺；快速固化；完全固化中图

Abstract:

Traditional light curing or heat curing adhesives are difficult to meet the needs of 3D printing molding. Thermal dual curing strategy is a hot research direction in the field of explosive 3D printing molding. In this paper, under the photothermal dual-curing strategy, a new type of acrylic ester hydroxyl-terminated polyether adhesive with the characteristics of rapid curing and complete curing in a short time was designed and synthesized. The obtained target adhesive has lower viscosity and better mechanical properties at low temperature. The optimum curing process parameters and the optimal material ratio as well as the elasticity of the photothermal double curing system were determined. The mechanical properties, thermal stability and tensile properties of the polymer were investigated. The experimental results showed that the target MAPTHF based adhesive system could be cured quickly within 5 s under ultraviolet light and completely cured within 3 h under heating. The tensile strength and elongation of the elastomer film formed by MAPTHF based photothermal dual curing were 3.15 Mpa and 350%. Compared with elastomer film formed by photo curing and thermal curing alone, it has better mechanical properties. Both thermodynamic properties and viscosity of the target adhesive meet the need of the 3D printing molding process and have been verified by 3D printing experiments. This kind of photothermal dual–curing adhesive solves the problem of slow curing speed and incomplete curing of traditional photo curing. It not only provide support for promoting the application of 3D printing in explosive formula but also lay solid foundations for solving the difficulty of precise rapid prototyping and accurate performance control of traditional explosive column molding process.