Development And Application Of Bio-based Polyols With Branched Chain In Polyurethane Foam Plastic

As a multifunctional organic materials,polyurethane foam has a huge application market in the current era of light industry.Its excellent properties enable it to be widely used in many national fields.With further research,its application areas are expanding and has a great potential for future market.However,traditional polyurethane foams are made from petroleum-based materials,which are difficult to recycle and degrade and will severely pollute the environment.Therefore,two bio-based polyols with different branched chain lengths were prepared using coconut oil and palm oil in this thesis.Moreover,n-butyldiethanolamine was used for comparison and application to polyurethane foam,and the research contents and conclusions are as follows.1.Coconut oil-based polyols and palm oil-based polyols were prepared from the biomass resources coconut oil and palm oil.IR analysis was used to follow the reaction process during the synthesis,and the molecular structures of the two produced bio-based polyols were analyzed using IR,~1H NMR and GPC to corroborate the successful preparation of the two polyols.The thermal stability properties of the two bio-based polyols were investigated by TG and DSC;and the viscosity properties were analyzed using a rheological analyzer.Due to the presence of branched chains,both bio-based polyols possess shear thinning properties,which facilitate the effective mixing of materials in synthetic polyurethane foams.The purity of the two bio-based polyols was extrapolated using their measured hydroxyl values,and the measured hydroxyl values were used for the formulation of the polyurethane foam.2.40%,80%and 100%of petroleum-based polyether polyols were replaced using coconut oil-based and palm oil-based polyols.And n-butyl polyol was used for the control to produce three flexible polyurethane foams containing different branched chain lengths.The microscopic pore structures of the obtained foams were observed by SEM and analyzed with the results of Texture analyzer,TG,DSC and DMA tests.40%substitution was used as an example to analyze the effect of incorporation of polyols with different branched chain lengths.The effect of incorporation of polyols with different branched chain lengths was analyzed with 40%substitution.The incorporation of coconut oil-based polyol and palm oil-based polyol led to a significant increase in the damping properties and mechanical strength of the polyurethane flexible foam.And among the three branched chains of 4 C,12 C and 16 C,the longer the branched chain with better microstructure,and mechanical strength of the corresponding polyurethane flexible foam.3.Coconut oil-based polyol and palm oil-based polyol were used to replace 40%,80%and 100%of petroleum-based polyester polyol.And n-butyl polyol was used as a reference and produced three polyurethane rigid foams with different branched chain lengths.The microscopic pore structure of the produced foams was observed by SEM,and the physical and mechanical properties and thermodynamics of the foams were tested using Texture analyzer,TG and DSC.The effect of the addition of three polyols with different branched chain lengths on the polyurethane rigid foam was also analyzed in combination with the thermal conductivity test with 40%substitution ratio.The addition of coconut oil-based polyol and palm oil-based polyol decreased the mechanical strength and increased the thermal conductivity of the polyurethane rigid foam,and the two bio-based polyurethane foams showed semi-rigid foam properties with the increased of substitution ratio.And among the three branched chains of 4 C,12 C and 16 C,the longer the branched chain with better microstructure,mechanical strength and thermal insulation properties of the corresponding polyurethane rigid foams.