Design,preparation And Properties Of Soy-based Functionalized Polymers

Because of the non-renewable nature of petroleum resources and the worldwide serious environmental problems and ecological disasters caused by the non-degradable nature of petroleum-based polymer materials,the research and study of biomass-based polymer materials are of great importance.However,most biomass-based polymer materials have high price,poor mechanical properties and poor processability,which limit their applications.Among all biomass materials,soy oil and soy protein have attracted wide attentions because of their high output,low price,good processability and good mechanical properties.Therefore,soy-based polymer materials have the best application prospects in all biomass-based polymer materials.At the same time,the two shortcomings of poor water resistance of soy protein and high functionality of soy oil restrict the applications of soy-based polymer materials.In this work,by building suitable polymer network systems,we can solve the problems of soy-based polymer materials,broaden their application,and further improve their value by functionalization.Specifically speaking:Firstly,by introducing thermo-reversible covalent bonds into the crosslinking network of traditional soy oil polyol polyurethane(T-S-PU),we successfully prepared the novel soy oil polyol polyurethane(N-S-PU),which has recyclable,shape memory and self-repairing properties.Thus,without affecting the excellent mechanical properties of soy oil-based polyurethane,we solve the biggest shortcoming of soy oil-based polyurethane(high functionality leads to thermosetting).The recyclable,shape memory and self-repairing properties of N-S-PU were studied by infrared spectroscopy,dissolution experiment,recycle experiment,differential scanning calorimetry,qualitative shape memory experiment,quantitative shape memory experiment,low temperature self-repairing experiment,high temperature self-repairing experiment and tensile experiment.The results of infrared spectroscopy show that N-S-PU was successfully prepared.Differential scanning calorimetry results show that the thermo-reversible bonds react positively and reversely at low and high temperatures,respectively.The results of dissolution and recycle experiments show that N-S-PU is recyclable compared with T-S-PU.Qualitative and quantitative shape memory experiments show that although both T-S-PU and N-S-PU have shape memory properties,N-S-PU has better shape memory properties,which is determined by a more regular crosslinking network.The results of low and high temperature self-repairing experiments and tensile experiment show that compared with T-S-PU,N-S-PU has self-repairing properties.Secondly,for the first time,we find a new photochromic phenomenon,which has never been reported before,from an ordinary polymer.In addition to light response,the color-change system also has thermal response,pH response,solvent response and mechanical response.Moreover,the color-change system is introduced into soy oil polyol polyurethane to make it functionalized,and the color-change soy oil polyol polyurethane with light and heat response is successfully prepared,thus turning the shortcoming of soy oil(high functionality leads to thermosetting)into advantage(high functionality leads to redundant active groups).The driving force of photochromic phenomenon,the structure of chromogen,the mechanism of photochromic phenomenon and the initiation mechanism of chromogen are studied by ultraviolet-visible spectroscopy,model compounds,confirmatory experiments,initiation experiments,molecular weight test and infrared spectroscopy.The results of ultraviolet-visible spectroscopy show that the ultraviolet light in sunshine is the driving force of this color-change phenomenon.The results of confirmatory experiments of model compounds show that the chromogen of this color-change system is one kind of diarylmethane dye(Michler's hydrol blue),and the mechanism of this color-change system is heterolysis:oxygen is the reactant,ultraviolet light is the reaction condition,and acid is the catalyst.The results of initiation experiment,molecular weight test and infrared spectroscopy of acrylate and acrylic acid show that the chromogen can be used as initiator,and the initiation mechanism is free radical initiation.Thirdly,we successfully prepare porous soy protein isolate/cellulose hybrid hydrogels using NaOH/urea/water as solvent,epichlorohydrin as crosslinking agent,soy protein isolate and cellulose as raw materials,therefore turning the shortcoming of soy protein(poor water resistance)into advantage(strong water absorption).The miscibility,morphology,structure,mechanical properties,gel behavior and swelling behavior of hydrogels are studied by wide-angle X-ray diffraction,thermogravimetric analysis,scanning electron microscopy,dynamic mechanical analysis,gel experiments,water absorption experiments and rehydration experiments.In addition,we prepare supercapacitor using the hydrogel as carbon source and measure its electrochemical performances.The results of wide-angle X-ray diffraction and thermogravimetric analysis show that the two components of hydrogels have good miscibility.The results of scanning electron microscopy,gel experiments and dynamic mechanical analysis show that cellulose mainly provides the mechanical properties of hydrogels.The results of water absorption experiments and rehydration experiments show that soy protein isolate mainly provides the water absorption performance of hydrogels.Scanning electron microscopy and electrochemical measurements show that the network structure inside hydrogels is similar to that inside the porous herbs.The supercapacitor prepared by using hydrogel as carbon source has excellent electrochemical performances.Fourthly,modified soy protein isolate(M-SPI)is prepared by hydrophobic end-capping modification,therefore solving the biggest shortcoming of soy protein isolate(poor water resistance).A series of soy-based semi-interpenetrating polymer networks(semi-IPN)are prepared by introducing M-SPI into the network of soy oil polyol polyurethane(S-PU).The structure,morphology,miscibility,mechanical properties and light transmittance of semi-IPN materials with different compositions are studied by infrared spectroscopy,density measurements,scanning electron microscopy,wide-angle X-ray diffraction,differential scanning calorimetry,dynamic mechanical thermal analysis,tensile experiments and ultraviolet-visible spectroscopy.The results of density measurements,differential scanning calorimetry,dynamic mechanical thermal analysis and light transmittance show that when the content of M-SPI is less than 20%,semi-IPN materials have excellent miscibility;when the content of M-SPI is more than 20%,phase separation begin to occur;with the content of M-SPI increasing gradually,the miscibility of semi-IPN materials turn bad.The results of scanning electron microscopy show that with the increase of the content of M-SPI,the size of dispersed phase(M-SPI)in continuous phase(S-PU)gradually increase.The results of tensile experiments show that when the content of M-SPI is high,semi-IPN materials behave as tough plastic;while when the content of M-SPI is low,semi-IPN materials behave as elastomer;we can adjust the mechanical properties of semi-IPN materials by changing the content of two components in semi-IPN materials.