Lignin-based Functional Water-Soluble Polymers Was Synthesized By Single Electron Transfer Living Radical Polymerization

Lignin is one of the most abundant renewable biomass materials.It has many advantages,such as renewable,biodegradable,stable,easy to be functional,rich in source,antibacterial,environment friendly and so on.The value of lignin in industrial production is less than 2%,most of which are used for low grade combustion,which not only pollutes the environment but also wastes the resources.Therefore,the high value utilization of lignin is the starting point,he polymers were synthsized of three kinds of lignin based functional water-soluble polymer through the “core-fisrt” way by a new polymerization method,which was called Single Electron Transfer Living Radical Polymerization(SET-LRP),and the main contents are as follows;1.The basic Alkaline lignin and 2-bromopropionyl bromide(BIBB)are used as raw materials Alkaline lignin initiators were prepared by Dimethylacetamidea(DMF)or tetrahydrofuran(THF)and triethylamine(TEA)as solvent.The hydroxyl of lignin in the solvent is Dimethylacetamidea(DMA)will be partially replaced,but the solvent is completely replaced in the solvent of tetrahydrofuran(THF)and triethylamine(TEA).The structure of the lignin initiator was characterized by infrared spectroscopy(FT-IR)and nuclear magnetic resonance(1HNMR),and the product was determined as the target product.2.Cu Br/tris(2-dimethylaminoethy)amine(Me6-TREN)was used as a catalytic system.The lignin initiator realized the single electron transfer free radical polymerization(SET-LRP)of acrylamide(AM)in the solution.The homopolymer of lignin based graft acrylamide(Lignin-g-P(AM))was prepared.Infrared spectroscopy(FT-IR)and nuclear magnetic resonance hydrogen spectrum(1HNMR)were used.The structure was determined,and the product was identified as the target product.The thermal stability and UV absorption function of lignin based acrylamide homopolymers were analyzed by ultraviolet visible spectrometer(UV)and thermogravimetric analyzer(TG).At the same time,it is also proved that the presence of lignin enhances the thermal stability of the polymer and has the UV absorption property.The effect of the reaction temperature,reaction time and the amount of catalyst on the synthetic polymer was investigated by the control variable method,and the best process conditions were determined.The kinetic performance of the polymerization is in accordance with the first order kinetic equation,and the molecular weight dispersion of the polymer is narrow,indicating that the synthesized polymers have the characteristics of reactive controllable polymerization.3.Using N,N-methyl formamide/water solution,lignin as initiator and Cu Br/tris(2-dimethylaminoethy)amine(Me6-TREN)as a catalytic system,the single electron transfer free radical polymerization(SET-LRP)of the copolymer of lignin acrylamide(AM)and Nisopropyl acrylamide was realized,and the infrared spectroscopy(FT-IR)was used.Nuclear magnetic resonance spectroscopy(1HNMR)was used to characterize the products and identify the target products.The UV visible spectrometer(UV)tests the conformation of the side chain molecular chain in Lignin-g-P(NIPAM)above 32 centigrade,and the hydrophilic chain like the hydrophobic chain change,so that the polymer has obvious temperature response.4.using Cu Br/(Me6-TREN)as a catalytic system,single electron transfer free radical polymerization(SET-LRP)was achieved in water and N,N-two methyl formamide solution,and lignin based acrylic acid(AA)and N-isopropyl acrylamide(NIPAM)polymer(Lignin-g-P(AA-co-NIPAM))were obtained.Infrared spectroscopy(FT-IR)and nuclear magnetic Co were used.Vibration hydrogen spectrum(1HNMR)was used to characterize the product structure and determine the target product.The performance of high precision pen based p H meter and ultraviolet visible spectrophotometer(UV)were tested.The results showed that polymers had p H response and temperature response.