摘要： 【目的】探究 3种软段（聚丙二醇 PPG、聚己内酯二醇 PCL、聚丁二醇 PTMG）对喷涂聚脲耐冲击性的影响，为高性能防护涂层的材料设计与工程应用提供理论依据。【方法】采用预聚体法制备了 3种软段结构的聚脲，通过傅立叶变换红外光谱仪（ FT-IR）、差示扫描量热仪（DSC）、循环拉伸测试、断裂能测试及落锤冲击试验，系统表征了其化学结构、热性能、能量耗散能力及耐冲击性。【结果】软段结构显著调控微相分离程度与力学性能。 PTMG基聚脲微相分离最完善，拉伸强度（约 28 MPa）和断裂能（ 1 078. 55 kJ/m²）最高，在厚涂层（ 2 mm）下易因脆性断裂加剧基材损伤； PCL基喷涂聚脲在拉伸强度、弹性模量和韧性间取得最佳平衡，其在厚涂层下能通过大变形有效吸收冲击能量，耐冲击防护效果最优； PPG基喷涂聚脲最柔韧，玻璃化转变温度（ Tg）最低，其防护效果依赖于足够厚的涂层（ ≥1. 5 mm）以实现能量耗散。 3种喷涂聚脲均表现出显著的应变率敏感性，弹性模量与拉伸强度随加载速率增加而提高。【结论】 3种喷涂聚脲的耐冲击性由软段化学结构（决定微相分离与本征韧性）和涂层厚度（决定能量吸收体积）共同决定。 PCL基喷涂聚脲因其优异的综合性能，是极端冲击防护（如爆炸、弹体撞击）厚涂层的最优选择； PPG基喷涂聚脲适用于缓冲减震场景；而 PTMG基喷涂聚脲则更适用于薄涂层或高强度但非极端冲击场景。

关键词: 喷涂聚脲, 耐冲击性, 微相分离, 能量耗散, 应变率效应

Abstract: ［Objective］This study investigated the influence of different soft segment types（PPG， PCL，PTMG）on the impact resistance of polyurea，aiming to provide a theoretical basis for designinghigh-performance protective coatings and their engineering applications.［Methods］ Three spraypolyureas with different soft segment structures were synthesized via the prepolymer method. Theirchemical structures，thermal properties，dynamic mechanical behavior，energy dissipation capacity，and impact resistance were systematically characterized using Fourier transform infrared spectroscopy（FT-IR）， differential scanning calorimetry（DSC）， cyclic tensile testing，and drop-weight impact experiments.［Results］The soft segment structure significantly affected the microphase separation andmechanical properties of spray polyurea. PTMG-based spray polyurea exhibited the most pronouncedmicrophase separation，along with the highest tensile strength（28 MPa） and fracture energy（1 078. 55 kJ/m²）. However，its tendency toward brittle fracture in thick coatings（2 mm） could exacerbate substrate damage. In contrast，PCL-based spray polyurea achieved an optimal balance between strength，modulus and toughness. Under thick coating conditions，it effectively absorbed impact energy through large deformation，demonstrating superior impact protection performance. PPG-based spray polyurea was the most flexible（with the lowest T_g）. Its protective effectiveness relied on sufficiently thick coatings（≥1. 5 mm）to facilitate energy dissipation. All spray polyureas tested showed significant strain rate sensitivity，with both modulus and strength increasing with higher loading rates.［Conclusion］The impact resistance of spray polyurea was determined collectively by the chemical structure of the soft segment（which governed the microphase separation behavior and intrinsic toughness）and the coating thickness（which dictated the volume of energy absorption）. Owing to its superior overall properties，PCL-based spray polyurea represented the optimal choice for thick coatingsunder extreme impact conditions（e. g.，explosions and projectile impacts）. PPG-based spray polyureawas more suitable for vibration damping and shock absorption applications，while PTMG-based spraypolyurea was better adapted for use in thin coatings or scenarios requiring high strength under moderate（non-extreme）impact.

Key words: spray polyurea, impact resistance, microphase separation, energy dissipation, strain rate effect

中图分类号: 

• TQ635