High Value Utilization Of Wast Polyacrylonitrile

Polyacrylonitrile production in our country has more than 600000 t/a,while in the process of production and spinning polyacrylonitrile,about 3%~5% of the polyacrylonitrile scrap,is China's current annual production of nearly ten thousand tons of acrylic waste.And this kind of waste is very difficult to depolymerization,not natural degradation,and not hot pressing molding.Recycling energy by burning way,will release a large amount of highly toxic substances,hydrocyanic acid,will pollute the environment.Therefore,this paper studies the utilization of waste polyacrylonitrile fiber,and makes it into a water-retaining agent,a filter loss controlling agent and a viscosifier,in oil well drilling fluids.Waste polyacrylonitrile fiber was determined by the experiment,the alkali hydrolysis and the optimal hydrolysis conditions of hydrolysis.In alkali hydrolysis,mass ratio of of polyacrylonitrile fiber to sodium hydroxide is 20:9,reaction time is11 h,the reaction temperature is 170?,apparent viscosity in clean water can reach135 mPa·s.In the hydrolysis of alcohols,the mass ratio of polyacrylonitrile fibers to ethanol is 1:8 and the reaction time is 4h.Hydrolyzed polyacrylonitrile water retention agent was determined by the experiment,the crosslinking agent for hexamethylenediamine,crosslinking reaction temperature and reaction time 2h and 95?,respectively,after adding a certain amount of biochar,water absorbtion rate is up to 88.65g/g,after adding a certain amount of humic acid,water absorbtion rate is up to 76.5g/g.Polyacrylonitrile hydrolysate was determined by experiment,polyacrylonitrile sodium grafted modified corn starch is used in the fluid loss agent,and discuss the fluid loss agent sodium hydrolysis of polyacrylonitrile and the optimal formula of modified corn starch,finally determine the amount of added starch and hydrolysis of polyacrylonitrile sodium mass ratio of 1:2,in 4% salt water and high temperature conditions,water loss low to 30 mL.Explores the use of polyacrylonitrile hydrolysate sodium preparation of polyacrylate calcium preparation conditions,determine the optimum reaction temperature is 70?,and the best reaction time is 5h,the optimalamount of adding calcium chloride is 50%.The optimal proportion of calcium polyacrylate and modified corn starch was discussed in this paper.When the ratio of calcium polyacrylate to starch was 2:1,the water loss was the lowest,20.6mL.Through the experiment,discusses the hydrolysis of polyacrylonitrile sodium bentonite slurry viscosity increasing effect,in 6.4% sodium base bentonite slurry,the hydrolysis of polyacrylonitrile sodium content was 0.2%,the highest apparent viscosity,in low solid sodium base bentonite slurry,bentonite base slurry apparent viscosity has increased,but the general effect.In 6.4% sodium base bentonite slurry was studied,the hydrophobic polymer addition amount of 0.29%,hydrolysis of polyacrylonitrile adding amount was 0.1%,the apparent viscosity of 22.5mPa·s,water loss is 10.4 mL,in low solid sodium base bentonite slurry,the hydrophobic polymer and hydrolysis of polyacrylonitrile add a ratio of 1:3,apparent viscosity of 15.5mPa·s,water loss is 40.4mL.Explores the generated by acrylic acid polymerization of polyacrylic acid calcium and hydrophobic polymer blends with low solid base bentonite slurry in the viscous effect,hydrophobic polymer and hydrolysis of polyacrylonitrile adding ratio is 1:15,apparent viscosity of 19.5 mPa·s,water loss is20.8 mL.