Synthesis And Properties Of Vegetable Oil-Based Polyols

Polyol is an important chemical intermediate,which has a wide range of applications in daily life,such as food,cosmetics,hygiene products,chemicals and medicine.With the development of global industry,non-renewable resources such as petroleum will be exhausted in a certain period of time,and the preparation of polymer materials based on biomass has attracted increasing attention.Renewable vegetable oils can be replaced with petroleum-based bio-based polyols by appropriate chemical modification.Metal-organic frameworks?MOFs?are a class of crystalline porous materials with periodic network structures formed by self-assembly of inorganic metal centers?metal ions or metal clusters?and bridged organic ligands,which are heterogeneous catalysts.An important platform.Although smaller particle size MOFs exhibit less diffusion and exhibit better catalytic performance,their separation and recycling after the catalytic reaction is difficult.The integration of MOFs with magnetic nanoparticles makes them easy to recycle and separate.In this paper,magnetic MOFs synthesized by stepwise assembly method were used as catalysts to explore the structure-activity relationship of catalysts.Different active groups were used to provide active centers.A series of catalysts were synthesized and applied to the ring-opening alcoholysis reaction of epoxidized soybean oil and methanol.To synthesize soybean oil-based polyols.In this thesis,Fe₃O₄ nanospheres were synthesized by solvothermal method.The core-shell structure Fe₃O₄@[Cu₃?BTC?₂]₂₀ was prepared by integrating Fe₃O₄ nanospheres with Cu₃?BTC?₂ by stepwise assembly.The catalyst was characterized by FT-IR,SEM,TEM and XRD.Then the catalyst was applied to the ring-opening reaction of epoxidized soybean oil and methanol,and the optimal catalytic conditions of the reaction were investigated.The experiment showed that the reaction time was 8 h,the temperature was 70°C,and the amount of catalyst was the total reactant mass.When the ratio of 4 wt%to alcoholic oil was 28,the ring-opening conversion reached a maximum of 89.13%.The product was characterized by FT-IR,¹HNMR,TG and rheological analysis.The recyclability of the catalyst was investigated by repeated use,and the experiment showed that there was no significant decrease in catalytic activity after the catalyst was repeated five times.Acidification of Fe₃O₄@[Cu₃?BTC?₂]₂₀ with concentrated sulfuric acid gave SO₄^2-/Fe₃O₄@[Cu₃?BTC?₂]₂₀.The effects of sulfuric acid immersion concentration,immersion time,calcination temperature and calcination time on the performance of the catalyst were investigated by FT-IR,SEM,TEM and XRD.Then it is used in the ring-opening reaction of epoxidized soybean oil and methanol.Under the optimal preparation conditions,that is,the reaction time is 6 h,the temperature is 60°C,and the amount of the catalyst is 4 wt%of the total reactant mass.When the amount ratio of the alcohol oil substance is 28,the ring-opening conversion ratio of the epoxidized soybean oil can be 92%.The product was characterized by FT-IR,1H NMR,TG and rheological analysis.Further,SO₄^2-/Fe₃O₄@[Cu₃?BTC?₂]₂₀ not only exhibited high catalytic activity,but also magnetic recovery and recycling easily,and there was no significant loss of catalytic efficiency after five cycles.Compared to the catalyst without acidification,the time required for the ring opening reaction is shortened,and the ring opening conversion rate is improved.The catalyst Fe₃O₄@[Cu₃?BTC?₂]₂₀ was sulfonated with more acidic chlorosulfonic acid to prepare Fe₃O₄@[Cu₃?BTC?₂]₂₀-SO₃H.By examining the optimal conditions of the reaction,that is,the reaction time is 8 h,the temperature is 70°C,the amount of the catalyst is 3 wt%of the total reactant mass,and the ratio of the alcohol to oil is 27 to make the epoxidized soybean oil.The ring opening conversion rate reached 96%,and the open-loop conversion rate was significantly improved.The product was characterized by FT-IR,¹HNMR,TG and rheological analysis.