| In order to alleviate the deteriorating oil resources and environmental climate, the demand for the preparation of environmentally friendly bio-based polymer materials has become an inevitable trend of social development. In this paper, the rosin-based epoxy resin(MPAER) and bio-polyurethane(COPU) were synthesized, and MPAER/COPU nanocomposites were prepared by added carbon nanotubes(CNTs) and graphene oxide(GO). The processof curing, degradation and performance of the nanocomposites were characterized. The results showed that the good nanocomposites were obtained. The main works are as follows:1. Maleopimarate(MPA) was synthesized from rosin and maleic anhydride by Diels-Alder reaction. Rosin-based epoxy resin(MPAER) was synthesized from MPA and epichlorohydrin, and was cured by MPA. The dynamic mechanical property, cure kinetics and thermal stability were characterized by DMA, DSC and TGA. The results show that the glass transition temperature of cured MPAER/MPA was 53.2 oC when the mass ratio of MPAER with MPA was 1:1. The cure kinetics could be simulated by the autocatalytic ?esták-Berggren(S-B) model, The average reaction order were 0.883 and 0.278 respectively, the average activation energy Ea for curing was 52.29 k J/mol。Friedman studies show that when it was 5 oC /min, the highest of activation energy was 81.63 k J/mol, and the thermal degradation reaction order was about 1.37.2. The castor oil-polyurethane(COPU) was synthesized, and the effects of the content of CNTs on the properties of COPU/MRER were researched. The curing process and properties of COPU/MRER/CNTs were characterized by FT-IR, TGA, DMA and TEM etc. The results showed that the glass transition temperature T_g for COPU/MRER/CNTs nanocomposite had highest for CNTs content 0.4 wt %, which was 150 oC and was 52.4 oC higher than the pure cured COPU/MRER. Thermal activation energy Ea of the nanocomposites increased with an increase of CNTs content in the range of 0–0.8 wt %. Friedman’s method suggested: when the content of CNTs is 0.4 wt%, the initial decomposition temperature(Tid) of nanocomposites was enhanced about 21 oC; the thermal degradation, Ea, hardness and impact properties of the sample were all improved at some extent.3. Graphene oxide(GO) was prepared from natural graphite by Hummers method. When the ratio of COPU with MPAER was 4:6, the COPU/MPAER nanocomposites with different GO content were prepared. The cured and properties of nanocomposites were characterized by FTIR, DMA,TGA and TEM etc. The results showed that the GO has a nano-structure. After GO was added into MPAER/COPU system. The glass temperature T_g of GO-containing nanocomposite increased obviously, which was 88.8 oC higher than pure MPAER/COPU when GO content was 0.8wt%. Thermal stability of GO-containing nanocomposites was also improved, the beginning to thermal degradation temperature was 81.5 oC higher than pure paterials when GO content was 0.4wt%. The hardness of coating film is increased from 5H to 6H, it’s adhesion and resistance to acid and alkali were all excellent but impact strength and elasticity drop.4. Rosin epoxy methacrylate(MREMA) and polyurethane acrylate(PUA) were synthesized from rosin epoxy resin, polyurethane acrylate(PUA) and acrylic acid. The MREMA/PUA was improved by different content CNTs, and was by UV. The effects of the content of CNTs on the dynamic mechanical properties, thermal properties, coating performance of materials were characterized. The result showed that the thermal stability of MREPA/PUA/CNTs composites was improved. Thermal degradation temperature(Tid) of the composites was 38.2 oC higher than pure MREPA/PUA materials. T_g of different contents of CNTs composites have corresponding changes, the T_g is the highest when CNTs content is 0.5wt%, which increase about 64.65 oC. |
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