Preparation And Properties Of Polyurethane Sponge Supported Absorbents For Organic Solvent

With the rapid development of pharmaceutical industry,the emissions of volatile organic compounds(VOCs)have increased.For example,there are a large number of butyl acetate waste spilling in the production of penicillin,which will cause serious environmental pollution problems without recycling.Conventional inorganic absorbent materials such as activated carbon are difficult to reproduce and post-treat.The volume expansion of organic synthetic absorbent materials is easy to cause blockage after absorption.Therefore,in order to recycle a small amount of organic solvent in water,this paper designed and prepared a series of polyurethane sponge supported absorbents,which had high absorption capacity of organic solvent in water,good recovery performance,low cost and could be used continuously in industrial applications.First,the oil absorption resin latex was prepared by emulsion polymerization,the optimum formula of the synthesis process was as follows:the monomer mass ratio was m(BA):m(St):m(MMA):m(AA):m(GMA)= 64:24:10:1:1,the crosslinking agent was 0.75%(of total mass of monomer),the initiator KPS was 0.6%(of total mass of monomer),the dosage of emulsifier was 3%and SDS:OP-10=3:1.Under the optimum formula,the reaction stability was excellent,and the absorbency of the prepared latex resin reached 10.35 g/g.Secondly,polyurethane sponge was selected as the skeleton material.The polyurethane sponge was activated with diisocyanate to introduce-NCO group and then modified by amination.After that,the polyurethane sponge and oil absorption resin latex were bonded to prepare the polyurethane sponge supported absorbents through the reaction between amino group and epoxy group.The optimum formula of the composite process was as follows:the time of dipping spong in latex was 1.5 h,the number of dipping times was 2,the temperature of heat post-treatment was 100 ?.Under the optimum formula,the oil absorption resin latex coated on the surface of the polyurethane sponge was appropriate.The absorption performance of the absorbent to butyl acetate was fine.The repeatability of the absorbent was excellent for the recovery rate maintaining above 97%after 8 cycles,The surface morphology,infrared spectroscopy and thermal stability analysis of the absorbent showed that the oil absorption resin latex was well coated on the surface of the polyurethane sponge and the thermal stability of the absorbent was good.Finally,the absorption properties of the polyurethane sponge supported absorbents for organic solvent were investigated.The absorbent had good oil-water selectivity and high oil retention rate.When the initial concentration of butyl acetate was 5 g/L,the flow rate of constant current pump was 0.5 mL/min and the height of packed column was 500 mm,the removal rate of dynamic absorption for trace n-butyl acetate in aqueous solution reached 98.68%.After reusing the absorbents in the dynamic absorption device for 8 times,the removal rate remained 98%-99%and the absorbents still exhibited good mechanical strength and flexibility.The results showed that the absorbents possessed stable reusability and could be used in continuous treatment of industrial waste.