金属配位键改性环氧化杜仲胶的制备与性能研究

Preparation and properties of metal coordination bond modified epoxidized Eucommia ulmoides gum

在环氧化杜仲胶(EEUG)中引入FeCl_(3),制备了基于Fe^(3+)-O金属配位键的EEUG复合材料,研究了Fe^(3+)-O配位键对EEUG硫化性能、结晶性能、力学性能及阻尼性能的影响。结果表明:Fe3+与环氧基团发生了络合反应,这种相互作用会随温度的升高逐渐减弱;配位键的存在会抑制EEUGβ晶型的形成,使复合材料结晶能力下降;配位键对杜仲胶硫化过程的影响主要体现在硫化诱导期,配位键数量越多焦烧时间越短;配位键通过充当“动态牺牲键”大幅提高了复合材料的力学强度,添加3份氯化铁后,EEUG-29.8%复合材料的拉伸强度由2 MPa提升至7 MPa;此外,Fe^(3+)与环氧基团之间的配位交联作用通过限制EEUG分子链运动实现了对复合材料阻尼性能的调控,相较于EEUG-29.8%复合材料,添加3份FeCl3后的复合材料阻尼峰位置由-25℃移动至0℃,有效阻尼温域由-40℃~-16℃升至-23℃~19℃,显著提高了EEUG复合材料常温下的阻尼性能。

EEUG composites based on Fe^(3+)-O metal coordination bonds have been prepared by introducing FeCl_(3)into epoxidized Eucommia ulmoides gum(EEUG).The effects of Fe^(3+)-O coordination bonds on the vulcanization,crystallization,mechanical and damping properties of EEUG were investigated.The results showed that Fe^(3+)is complexed with the epoxy group,and the interaction decreases with increasing temperature.The presence of the coordination bond can inhibit the formation of the EEUGβ-crystal form and decrease the crystallization capacity of the composite.The effect of coordination bonds on vulcanization of Eucommia ulmoides gum was mainly reflected in the induction period of vulcanization,the larger number of coordination bonds,and shorter scorch times.By acting as a“dynamic sacrifice bond”,the mechanical strength of EEUG-29.8%composites is greatly improved.After adding 3 phr FeCl_(3),the tensile strength of EEUG-29.8%composites is increased from 2 MPa to 7 MPa.In addition,the coordination crosslinking between Fe^(3+)and epoxy groups can control the damping performance of the composite by limiting the movement of EEUG molecular chains.Compared with EEUG-29.8%composites,the damping peak position of the composite after adding 3 phr FeCl_(3)moves from-25℃to 0℃.The effective damping temperature range increased from-40℃~-16℃to-23℃~19℃,which significantly improved the damping performance of EEUG composites at room temperature.