Synthesis Of Vegetable Oil-based Polyurethane Elastomer And Precursor And Performance Research

In order to protect the environment and reduce the consumption of oil,researching renewable energy to replace oil is the main research direction now.Vegetable oil is an environmentally friendly and renewable resource with a wide range of sources and low prices.It is an excellent alternative to petroleum products.If vegetable oil is used to replace non-renewable petrochemical resources to prepare chemical products,not only can it relieve the pressure caused by the reduction of non-renewable resources,but it can also ensure the sustainable development of chemical products and contribute to the progress of society.At present,researchers have produced polyurethane materials from vegetable oil-based polyols,and compared them with petroleum-based polyurethane materials,and found that vegetable oil-based polyurethane materials have better performance.In this paper,a vegetable oil-based butyltetraol ester was prepared by transesterification.An intermediate vegetable oil-based cyclic carbonate was prepared by the transesterification reaction between vegetable oil-based tetraol ester and dimethyl carbonate.Raw materials were studied for synthetic polyurethane elastomers,and mechanical properties of polyurethane elastomers were tested.Characterization methods such as infrared and nuclear magnetic resonance were used to detect polyols and cyclic carbonates.The main research contents of this paper are as follows:(1)First,the raw material glyceryl trilinoleate is treated,and it is reacted with methanol to prepare methyl linoleate.Using methyl linoleate as a raw material,anhydrous sodium carbonate as a catalyst was transesterified with glycerol,trimethylolpropane,and butanol in the presence of three alcohols to synthesize a vegetable oil-based polyol.The results show that: 1)The best reaction temperature for preparing polyol from glycerol is180?,and the catalyst is used in an amount of 0.6% by weight based on the mass of the oil.The optimal molar ratio of methyl linoleate to glycerol is 1: 3.,The reaction time is 4h;2)the best reaction temperature for preparing polyhydric alcohols with trimethylolpropane is 190?,the catalysis and the amount is 0.8wt% of the mass of the raw material oil,Thebest molar ratio is 1: 3.5,and the reaction time is 3h.3)The best reaction temperature for the preparation of polyhydric alcohols using butane tetraol is 170?,and the amount of catalysis is 0.8wt% of the mass of the raw material oil.The optimal molar ratio of alcohol is 1: 2.5,and the reaction time is 4h.(2)Catalyzing the reaction of vegetable oil-based monobutyltetraol ester and dimethyl carbonate(DMC)with anhydrous potassium carbonate and triethylamine as catalysts to synthesize vegetable oil-based cyclic carbonate,respectively,and discussed the process.The results show that: the optimal process conditions are: 1)anhydrous potassium carbonate as the catalyst,the reaction temperature is 100?,the reaction time is 1 hour,the molar ratio is 1: 2,the catalyst is 0.6wt%;2)triethylamine is the catalyst.The reaction temperature was 90?,the reaction time was 2 hours,the molar ratio was 1: 3,and the catalyst was 40 ml.(3)A vegetable oil-based cyclic carbonate is used as a raw material,and the molar ratio of each component is polyethylene glycol: diisocyanate: diol: vegetable oil-based cyclic carbonate = 1: 2: 2: 2.The mechanical properties are discussed.The results show that the reaction temperature is 100?,the reaction time is 1 hour,the molecular weight of polyethylene glycol is 20,000,and 1,6-hexanediol is the reactant with the best tensile performance.