The Extraction, Modfication And Application Of Eucommia Ulmoides Gum And Preparation Of Shape Memory Materials

In this paper, the organic phase-aqueous phase method was used to extract natural Eucommia ulmoides gum(EUG) and the product was characterized. We blended natural rubber(NR) with EUG and studied the effect of EUG amount on processing properties and vulcanized rubber comprehensive performance. We prepared epoxied Eucommia ulmoides gum(EEUG) by emulsion method and EEUG was used to modify SBR/silica composites. The effects of epoxy degree and EEUG amount on the performance of SBR/silica composites were investigated and EEUG-40 was compared with traditional silica dispersant. EUG was used as material to prepare EUG foam shape memory materials and EUG/HDPE shape memory materials. We mainly studied the effects of crosslinking degree and foaming degree on the performance and dual shape memory effect of EUG and we also studied the triple shape memory effects of EUG/HDPE shape memory materials with different crosslinking degree, HDPE amount and talcum amount.Firstly, we used the organic phase-aqueous phase method to simplify the extraction and separation processes of EUG and the extracted EUG was characterized by various methods and the results showed that: The molecular weight of enzyme pretreated EUG was 300000 to 400000 and the molecular weight distribution is relatively narrow; and its trans-1,4-structure content was nearly 99% and β and α crystal form was present in EUG we got. EUG was also used to prepare Natural rubber composites for car radial tire and the result showed that addition of EUG could improve the properties of Natural rubber tire compounds greatly. When the amount of EUG was 10 phr, tensile strength improved 5.0% and tear strength improved 13.8% separately. The wear resistance for all the compounds increased while heat-buildup decreased with the addition of EUG. Meanwhile, the introduction of EUG might reduce processing properties of NR composites.Secondly, in terms of the modification and application EUG, we use EUG as raw material and peracetic acid to prepare epoxied Eucommia ulmoides gum(EEUG) with different epoxy degree by emulsion method and EEUG was used to modify SBR/silica composites. The results showed that: the composites showed higher processing performance and the vulcanized rubber exhibited higher mechanical properties, wear resistance, lower compression heat-buildup and better dispersant of silica in SBR matrix when it was modified with EEUG with higher epoxy degree. EEUG with epoxy degree of 40%(EEUG-40) could improve silica dispersion and reduce "Payne" effect and it can also improve the physical and mechanical properties of vulcanized rubber and the dynamic mechanical performance of SBR/silica composites with a proper amount. But when EEUG-40 amount was too large, the mechanical properties, processing properties and dynamic mechanical properties SBR/silica composites were decreased and silica tended to gather. When EEUG-40 was 3 phr, the comprehensive performance reached the best. When used as interfacial modifier to promote the dispersant of silica in SBR, EEUG-40 performed as well as traditional silica dispersant and EEUG is an excellent macromolecular interfacial modifier for SBR/silica composites.Finally, we prepared EUG foamed shape memory materials, using Expancel 920DU40 as vesicant. The influence of the sulfur amount and the Expancel 920DU40 amount on its overall performance were studied and results showed that: increasing the sulfur amount, the crystallinity degree and Tm of EUG decreased and mechanical properties firstly decreased then increased. In addition, the shape memory properties decreased with increasing sulfur amount and when sulfur amount was 0.8 phr it performed best. Increasing the Expancel 920DU40 amount, the crystallinity degree and Tm of EUG increased slightly, the shape memory properties was alsmost not affected by Expancel 920DU40 amount. We then studied triple shape memory effects of EUG/HDPE composites with various DCP amount, HDPE amount, and S/DCP ratio. Results showed that: the crystallinity and Tm of EUG and HDPE decreased EUG significantly and physical and mechanical properties went down sharply with increasing DCP amount, meanwhile shape memory properties of EUG/HDPE composites decreased and when DCP amount was 1phr the comprehensive performance reached best. In terms of HDPE amount, the crystallinity degree of HDPE increase the crystallinity degree and Tm of EUG decreased when it increased but Tm of HDPE changed less. The foam degree increased and the mechanical strength was reduced while modulus and hardness was enhanced due to the addition of HDPE. Shape memory properties EUG/HDPE showed little linear relationship with HDPE amount and when EUG/HDPE was 80/20 it performed best. When sulfur amount was certain, increasing DCP amount the crystallinity degree and Tm HDPE and EUG were both decreased and the foam degree was not related to DCP amount. And mechanical properties firstly increased and then decreased and the hardness was significantly reduced, increasing the DCP amount. As for shape memory properties, the thermal stimulation response temperature(Tr) and the shape recovery ratio(Rf) was increased, increasing DCP amount.