Study On Fermentation Extraction Technology Of TKS Rubber

Coal,petroleum,steel,and natural rubber are known as the four major industrial basic materials in the world.As one of them,natural rubber is favored in all walks of life in China.Due to the limited planting area of natural rubber in China,the output of natural rubber is far Less than the demand,China's natural rubber market consumes more than 80%of its consumption,which is very unfavorable to all walks of life in China.It causes downstream tire companies to face high import costs of natural rubber,so it is urgent to find a second natural rubber.To solve the problem of insufficient natural rubber production in China.At present,the second natural rubber resources that are widely studied are Taraxacum koksaghyz rubber(TKS rubber),Eucommia ulmoides gum(EUG)and Guayule rubber.China's research work on TKS is still in the basic development stage.The research work mainly focuses on the genetic modification,seedling selection,planting and harvesting of TKS,while the research on the extraction technology of dandelion rubber is less involved.The research work on the extraction technology of TKS rubber is divided into three parts.The first is the research on the distribution of rubber in the roots of TKS and the analysis of the main components of TKS,the second is the research on the fermentation extraction technology of TKS rubber,and the last is Study on the characterization of TKS rubber.1.Scanning electron microscopy(SEM)observations were taken on transverse and longitudinal sections of TKS dried roots to study the distribution of rubber in TKS roots.The main components of TKS dried roots were tested and found that the cellulose content accounted for 12.94%,the hemicellulose content accounted for 6.85%,the lignin content accounted for 20.24%,the reducing sugar content accounted for 3.57%,and the inulin content accounted for 21.87%.Lignocellulose,which accounts for 40%of the dry root of TKS,has become the main impurity component of the extracted rubber.Therefore,we need to remove lignocellulose from the bondage of rubber when purifying the extracted rubber,which is an indispensable link for extracting high-quality rubber.2.For the fermentation extraction process of TKS rubber,this paper establishes a process route for the extraction of rubber and the production of ethanol as a by-product.The process route is divided into three parts,which are the pretreatment process of TKS and the enzymatic hydrolysis process.And fermentation process,and the pretreatment process is the most important step in the entire gum extraction process.Aiming at the influencing factors of the pretreatment process(reaction temperature,reaction time,solid-liquid ratio and solution concentration),we designed based on the experimental results of single factors four factors and three levels orthogonal experiments of pretreatment process parameters.The optimal pretreatment process was established from the results of orthogonal experiments.The optimal pretreatment process parameters were reaction temperature 140?,reaction time 30min,solid-liquid ratio 1:9 and acid.The concentration is 3%.The extraction of high-purity TKS rubber and the preparation of biofuel ethanol were achieved through the enzymatic hydrolysis and fermentation process.The highest purity of the extracted TKS rubber was 95.54%,and the highest yield of ethanol was 2.05%.(100g TKS root material can produce 2.05g ethanol when extracting rubber),and the by-product biofuel ethanol is successfully prepared while extracting TKS rubber.3.The structure and performance of TKS rubber and natural rubber(NR)were characterized and compared.According to the GPC,FTIR,DSC,TGA and NMR test results of the two,there is a certain difference in molecular weight between TKS rubber and NR,but can fully meet the needs of industrial processing;FTIR,NMR,TGA and DSC spectra of TKS rubber and NR are not significantly different.The mechanical properties of TKS rubber and NR are analyzed.The results show that the TKS rubber extracted by fermentation does not have the strain-induced crystallization phenomenon of NR at room temperature,but the TKS rubber has an elongation at break of several times the NR,which makes the TKS rubber have better tensile effect.TKS is currently the only gum-producing resource that can replace natural rubber trees.The ethanol produced as a by-product in the process of rubber extraction of TKS by fermentation can bring certain additional economic benefits and can reduce the production cost of TKS rubber extraction.The comprehensive utilization and development of TKS is of great significance to the development of TKS rubber,so the rubber extraction process in this paper has certain industrial value for the development of TKS rubber.