Research Of Components And Structure Of Natural Rubber Latex In Primary Process

The components and structures of natural rubber latex are easy to change in primary process,resulting in different performance of natural rubber products and consistency of the quality of NR products.Therefore,the aims of the present study were mainly to investigate the changes of the components and structures of natural rubber latex in the process of the centrifugal concentrated latex production and in the process of the block rubber production.So as to form a conclusion that which is the key procedures to affect the components and structures of natural rubber latex in the process of the block rubber production,which is provided many theories for the basic research,modification,and basis production of NR.In the process of the centrifugal concentrated latex production,natural rubber latex obtained from the tapping,clarifying,adjusting and centrifuging,were determinated about the contents of rubber hydrocarbon,proteins,lipids,acetone extracts(AE),water extracts(WE)and ash.And analyzed the surface morphology and size of NR particle,the molecular weight,chain-linked constitutes,isomers content of isoprene,degree of unsaturation,crosslink network structure and thermal degradation temperature of NR molecular chains.The results of research for the components and structures of natural rubber latex in the process of the centrifugal concentrated latex production shown that all of the components and structures didn't change significantly in the steps of clarifying and adjusting.However,the components and structures have a clear change in the centrifuging.More specifically,the contents of rubber hydrocarbons,lipids and acetone extracts(AE)all increased,while,the contents of water extracts(WE),proteins and ash all decreased beacause the skim latex were removed.Whatmore,the contents of rubber hydrocarbons,lipids and WE changed more apparently,whose variations were 29.90%,0.6093%,and 0.8266%,respectively.At the same time,the surface morphology of NR particles changed,and the particle size decreased after the centrifugating.Furthermore,the molecular weight,cis-1,4 isoprene structures content,crosslink density,thermal degradation temperature and degree of unsaturation of the molecular chains all increased.So,the centrifuging is the key manufacturing procedure in the process of the centrifugal concentrated latex production.Whatmore,with the changes of proteins and lipids,all of the morphology and size of particle,molecular weight,chain-linked constitutes,and crosslinked network structure of NR molecule chain changed.In the process of the block rubber production,that is,in the process of latex-grade standard NR(block NR)production by grinding-granulation,NR samples obtained from the mixing,coagulating,crushing,milling,prilling,drying and pressing,were determinated about the contents of rubber hydrocarbon,proteins,lipids,acetone extracts(AE),water extracts(WE)and ash.And analyzed the molecular weight,chain-linked constitutes,isomers content of isoprene,degree of unsaturation,crosslink network structure and thermal degradation temperature of NR molecular chains.The results of research for the components and structures of natural rubber latex in the process of the block rubber production,the content of rubber hydrocarbons increased gradually.After the coagulating,the contents of proteins,lipids,and AE increased obviously,while,the contents of WE and ash decreased.From the crushing,the contents of proteins,lipids,AE and WE had kept decreasing.Moreover,because the content of rubber hydrocarbons increased,the content of cis-1,4 isoprene unit gradually increased.And,the molecular weight,cis-1,4 isoprene structures,degree of unsaturation of the molecular chains and crosslinked network structure are all easier to change.More remarkable,different molecular structures of NR chains are affected by different manufacturing procedures.