Study On Preparation And Properties Of UV-crosslinkable Eucommia Ulmoides Gum With High Elasticity And Wear Resistance

Thermoplastic elastomer?TPE?has both the processability of plastics and the physical property of vulcanized rubber.Similar with TPE,Eucommia Ulmoides gum?EUG?,as a kind of renewable diene rubber resource,possesses the duality of rubber and plasticity,which shows the wide application prospect in the field of industrial basic materials.With the chemical modification of 1,2,4-triazoline-3,5-diones?TAD?,modified EUG is endowed with the good resilience at room temperature,along with promotions in other mechanical properties.Therefore,it is an important subject for EUG industrial application to adjust the physical-chemical properties of material with modifications,thus achieving the purpose of regulating and controlling the mechanical properties.In the second chapter,TADs containing different functional groups were synthesized.By Alder-ene reaction,binary TAD-modified EUG(Th_xPT_0.2EUG)was prepared with good integrated mechanical properties.The structures of products were characterized.The thermal and crystallization properties were analyzed by TGA,DSC,and XRD,which indicated that modified EUG ultimately transformed into amorphous materials at high degree of TAD binary-modification and had wide range of application temperature.Tensile test demonstrated that Th₁PT_0.2EUG displayed high tensile strength of 36.57 MPa and toughness of 152.14MJ/m³,meanwhile,Th₂₀PT_0.2EUG exhibited much better elongation at break of 1165%and recovery rate of 60%.Blending of Th_xPT_0.2EUG and carbon-white?SiO₂?made the abrasion resistance performance of products better.What?s more,SEM revealed that the compatibility between Th_xPT_0.2EUG and SiO₂ improved.In the third chapter,on the basis of single TAD-modification,a kind of modified EUG containing cinnamoyl group(Th₂₀Cin_yEUG)was prepared,which could be crosslinked under UV irradiation.Crosslinking degree was characterized by UV-vis spectra.The result showed that crosslinking degree of sample in solution was larger than that of sample in film.Tensile test illustrated that Th₂₀Cin_yEUG after irradiation displayed higher tensile strength and recovery rate over 70%.By comparison,there was a close relationship between mechanical properties and crosslinking degree.Different from conventional cross-linking systems,photo-crosslinking reaction was provided with the controllability and simplicity,and Th₂₀Cin_yEUG seemed to become a suitable candidate for intelligent materials.