Binary Modification of Eucommia ulmoides Gum Toward Elastomer with Tunable Mechanical Properties and Good Compatibility

Abstract

Eucommia ulmoides gum (EUG) was applied in blend rubber with a heavily limited amount because of its duality of rubber and plastic, and an efficient way of triazolinedione (TAD)-based Alder-ene reaction was used to improve the elastic properties of EUG. Binary modification of EUG with two TADs containing hexyl and polyhedral oligomeric silsesquioxane (POSS) groups were conducted to generate the modified EUG elastomers with tunable mechanical properties and good compatibility by varying TAD contents. When the low hexyl (1%) and POSS (0.2%) TADs incorporated, the modified EUGs displayed high tensile strength of 36.57 MPa with the elongation at break of 876%, and thus high toughness of 152.14 MJ m −3 . If high contents of hexyl (20%) and POSS (0.2%) TADs employed, the modified EUGs exhibited excellent elongation at break of 1165% and recovery rate of 60%, and especially its loss factor reached up to 0.83-0.65 at 20-70 C. Therefore, the modified EUGs containing the polar urazole and POSS groups should be a novel elastomer with good compatibility, wear resistance, and damping properties.

A high toughness elastomer based on naturalEucommia ulmoidesgum

“…The peaks at 135.0 and 124.3 ppm were attributed to the unsaturated carbon of EUG. The peaks at 39.8 and 26.7 ppm belonged to the CH 2 and the peak at 16.0 ppm corresponded to the CH 3 of EUG 43 . After hydrogenation, the new peaks appearing at 19.6 and 32.4 ppm were attributed to CH 3 and CH of the saturated unit, respectively, and the peaks at 37.1 and 25.4 ppm were attributed to CH 2 of the saturated unit 51 .…”

“…The thermal stability of HEUG was characterized by TGA, and the results are shown in Figure 5(a). The thermal decomposition temperatures ( T d , 5% weight loss) is an important parameter of the thermal stability of materials 43 . Both EUG and HEUG showed a single step degradation, but T d of HEUG increased with the increase of HD (summarized in Table 1).…”

“…The thermal decomposition temperatures (T d , 5% weight loss) is an important parameter of the thermal stability of materials. 43 Both EUG and HEUG showed a single step degradation, but T d of HEUG increased with the increase of HD (summarized in Table 1). Compared with the EUG, T d of HEUG-85.9% was increased by 31 C. This was because the hydrogenation reaction increased the saturation of EUG molecular chain, and the carbon-carbon double bond was transformed into a more stable carboncarbon single bond, thus increasing its heat resistance.…”

“…For example, the vulcanization of EUG is carried out at a relatively high temperature using special formulation and stringent processing conditions, which prevents EUG from being used in large-scale owing to the high cost. Subsequently, chemical modification methods such as epoxidation, [36][37][38][39] grafting [40][41][42][43] were used to prepare EUG based elastomers. Our research group successfully prepared EUG based elastomers by using epoxy ring-opening reaction 44 and cyclization 45 modification methods, and applied them to self-healing, damping materials fields.…”

Thermal, mechanical, and tribological properties of epoxy polymer/EPU blends reinforced by low concentration of octaaminophenyl POSS

“…In addition, the tribological properties of POSS and related additives on polymer nanocomposites have been reported. Zhao et al [24] prepared modified Eucommia ulmoides gum containing polar urazole and POSS groups with good wear resistance. Zhang et al [25] prepared POSS-SiO 2 /cyanate ester composites with high impact and flexural strengths, thermal stability, and tribological properties.…”