The Study Of Preparing Telechelic Liquid Rubber By The Degradation Of Natural Rubber

Liquid natural rubber is one of new polymer materials in developing.It has beenused in rubber reinforcement, toughening plastics, etc., and has broad applicationprospectsin in industry, agriculture, aviation, aerospace and other fields. and itspreparation is an important research direction in the field of rubber materials.Carbonyl-telechelic liquid natural rubber (CTLNR) was prepared by two-stepmethod, firstly epoxidized natural rubber (ENR) was prepared with natural rubber (NR)as raw materials, formic acid and30%hydrogen peroxide in situ generated peracetic acid,The optimum conditions of the preparation of ENR was determined by single factor andorthogonal experiments. The conditions of preparing ENR with largest epoxy is formicacid accounted for0.53of NR,30%hydrogen peroxide added accounted for1.43of NR,675r/min as stirring speed and reaction time as4h at40?, the epoxy of the preparationENR was2.67%. Preparing CTLNR with reaction time as3h at30?,[H5IO6/NR] as0.001mol/g, the lowest molecular weight of CTLNR was2947. The chemical structure ofENR and CTLNR were characterized by using Infrared spectroscopy (FT-IR).NR as raw material, H5IO6as oxidant, using one-step to prepare CTLNR; solventspecies, the amount of H5IO6, reaction temperature and reaction time on the NRdegradation effect were investigated through single factor and parallel experiments todetermine the conditions of preparing CTLNR. The results show that the optimumconditions of preparing CTLNR in chloroform was H5IO6/NR as0.0012/1mol/g,35?asreaction temperature,60min as reaction time. In toluene solution, it was H5IO6/NR as0.0012/1mol/g,40?as reaction temperature,100min as reaction time.120#gasolinesolution, it was H5IO6/NR as0.002/1mol/g,60?as reaction temperature,120min asreaction time. CTLNR were characterized by using FT-IR and1H-NMR.Using sodium borohydride (NaBH4) reduced CTLNR to prepare HTLNR. Thechemical structure of HTLNR were characterized using FT-IR and1H-NMR. FT-IR and1H-NMR spectral showed that HTLNR with hydroxyl at the end.