| In this paper, vinyl acetate rubber (EVM)/polylactic acid (PLA) blends wereprepared by Haake mechanical torque rheometer with the use of melt. Effects ofprocessing temperature, rotor speed, blends ratio and the curing system for the dampingand mechanical properties of EVM/PLA blends were studied; the damping property ofEVM/PLA blends hybridwith dopamine, hinder phenol AO-60, super branched polyorand polyors sold by market were investigated by dynamic viscoelastometer (DMA), thedamping mechanism was investigated by differential scanning calorimetry (DSC) and insitu infrared spectroscopy. Finally, the damping hot stability of EVM/PLA/super branchedpolyor was investigated by thermal gravimetric (TG), X-ray diffraction (XRD) and DMA.Experimental results were as follows.EVM was incompatible with PLA, the start processing temperature of160°C and therotor speed of50r/min were the best technology when considered the mechanical anddamping properties of blends; the favourable quality ratio of EVM/PLA blends was80/20;when the vulcanization system was DCP/TAIC=1.0/0.5, the damping properties of thematerial was better. After the preparation of EVM/PLA/small organic molecule composite,the results were showed as follows: Dopamine could not improve the damping propertiesof the material, which played the role of the rigid particles in the material; hinderedphenol AO-60could improve the damping factor and the glass transition temperature (Tg)of materials,10parts AO-60broadened the effective temperature from87.3°C to101.1°C; super branched polyol could improve the damping factor of materials withoutchanging the Tg of materials; the commercial polyor210could improve the dampingproperties of EVM/PLA blends, the effective damping temperature range of EVM/PLAblends was broadened to72.5°C, the commercial polyor330,3628could not improve thedamping properties of EVM/PLA blends. The super branched polyol played the role of a compatibilizer in EVM/PLAcomposite material, and it had a better affinity with PLA, and could greatly improve thedamping properties of EVM/PLA blends, due to its own dynamic mechanical propertiesand the hydrogen bonds with matrix polymer,10parts polyol broadened the effectivetemperature from66.5°C to104.8°C, while30parts can broaden to183.3℃.The variabletemperature IR spectra showed the existence of hydrogen bonds with the OH, C=O andC-O-C in the EVM/PLA/super branched polyol blends, the dissociation of hydrogenbetween C=O and OH showed a “blue shift†and the “red shift†occurred when thehydrogen bond between C-O and OH dissociated.The EVM/PLA/super branched polyor blends experienced different degrees of heattreatment, the re-crosslinking of EVM, the cold crystallization of PLA occurred after that,resulting in the decrease of damping property of EVM/PLA blends; after the heattreatment, the migration and enrichment of super branched polyor occurred in theEVM/PLA blends, and a new relaxation peaks appeared in Tanδ-T curve. |
