Studies On The Control Of The Process Of Liquefaction Of Banana Pseudo-stem And Component Analysis&Application On Liquefied Products

Biomass resource is renewable and environmental friendly,annually,the earth produce large quantity of biomass.It has broad applications prospects.Biomass can used to produce chemical products.While liquefaction of biomass is an efficient and energy saving method of using biomass resource.The solid biomass could be transferred into liquid.In this paper,banana pseudo-stem is one of lignocellulosic materials which was used as raw material and it had been liquefied by polyether polyol.Analyzing changes happened in the process of liquefaction of residue and liquefied products,to explore the possibility of utilization of liquefied products.Lastly,polyurethane adhesive was synthesized with liquefied products.FT-IR,XRD,TG,SEM,GPC,GC-MS and 1H-NMR,13C-NMR had been used to analyze the partial products.Here are the main conclusions and main contents.(1)The temperature of the reaction system is 150 ?.Liquefaction time,liquid-solid ratio,amount of catalyst which affected contents of cellulose in banana pseudo-stem residues were determined by single factor experiment and the orthogonal experiment.Results show that with the growth of liquid-solid ratio,liquefaction time and amount of catalyst,contents of cellulose in banana pseudo-stem residues increased at first then decreased.Optimum liquefaction process are as follows,liquid-solid ratio is 12:1,liquefaction time is 60 min and amount of catalyst is 2.5 mmol/g(number of moles of catalyst/quality of banana pseudo-stem).Proportion of cellulose in banana pseudo-stem residues is 65.37%.Banana pseudo-stem,banana pseudo-stem residues and cellulose of banana pseudo-stem residues were analyzing with FT-IR,TG,XRD and SEM.According to FT-IR,the absorption peaks of lignin disappeared in residue.Results from XRD show the crystallinity of residue and cellulose are 51.96%and 62.37%,respectively,which were higher than the crystallinity of banana pseudo-stem of 44.83%.Results of TG suggested the thermal stability of residue is higher than banana pseudo-stem while lower than cellulose.SEM indicates that degradation reactions take place in the surface of banana pseudo-stem.It is concluded that partial lignin and hemicelluloses are removed by liquefaction while cellulose remained.(2)It was showed that the contents of liquefied products were complicated.There were few reports focused on the liquefied products which had been isolated with column chromatography.Mixtures of C and D had been isolated from the liquefied products with extraction,according to the results from thin layer chromatography,ethanol and acetone were chosen as eluent for column chromatography.The ratio of these two solvents was 50:50.The unknown substances from liquefied products were analyzed with FI-IR,UV,'H-NMR and 13C-NMR.The results got from UV spectrum,FI-IR,1H-NMR,13C-NMR showed that C-1 and C-3 have the same structural fragments,D-l and D-2 the same too.In summary,there are at least 3 kinds of these substances with follow structures.Here are the following results.?4-carbonyl-ethyl n-valerate ?2-hydroxy-3-methy-diethyl succinate ?3-carbonyl-18 carbon alkyl.(3)Liquefied products are rich in hydroxyl,which can replace the traditional polyether for the preparation of polyurethane adhesive.Temperature,liquid-solid ratio and amount of catalyst all have effects on the residue contents.When increase temperature,liquid-solid ratio and amount of catalyst,the residue contents are decreased.With time prolonging,hydroxyl number is decreased while acid number is raised.Liquefied products were used as the raw material for the partial substitution of PEG400 to produce liquefied products based polyurethane adhesive by reacting with 4,4'-MDI.The lap shear strength is decreased as the percentage of the substitution of PEG400 by liquefied products increased,while the thermal stability is improved.When the substitution of PEG400 by liquefied products was 16.70%,the lap shear strength of liquefied products based polyurethane adhesive got the highest value(4.40MPa).Liquefied products based polyurethane adhesive with good chemical resistance and the failure mode of glue joint is cohesive failure which is the ideal failure mode.