Study On Regeneration Of The Waste Expandable Polystyrene Plastics By Suspension Distillation Method

Expandable polystyrene is widely used in construction,packaging,electronic appliances,vehicle manufacturing,decoration materials and other fields.In China the output of polystyrene,which uses styrene as the raw material,ranks second in the world.Most of the polystyrene products are abandoned directly after using,which creates a waste of resources.And because of their light weight,large volume,resistance corrosion and ageing resistance,it can be a source of “white pollution”,which can lead to great damage to the ecological environment.Therefore,how to recycle and resource utilization for polystyrene is an important issue to be settled urgently.At present,there are several kinds of main methods to recycle polystyrene at home and abroad: taking advantage of waste polystyrene foam directly after being crushed,the heating melting method,the solvent dissolution method,the pyrolysis method and the dissolved polymerization method.Among them,the solvent method,which is simple and low energy consumption,can be directly obtained polystyrene resin.It can maintain as the original polystyrene molecular chains,and is almost the same to polystyrene prepared by suspension polymerization on properties.While the other methods are poor product quality or low economic benefits.The influences of stirring rate,surfactant concentration,oil-water ratio and heating rate on the particle size of polystyrene beads are investigated with regenerating the waste expandable polystyrene plastics by suspension distillation method.The microstructure,chemical structure,molecular weight,physical properties(density,water absorption and corrosion resistance),mechanical properties,and thermal stability of the material are tested.Their various properties are compared with the enterprise polystyreneGraphite/polystyrene composites are prepared by using waste polystyrene foam and natural flake graphite solvent blending as raw materials.The chemical structure,microstructure and thermal stability of the composites are studied by FT-IR,XRD,SEM,TG / DTG.And their mechanical properties are determined.The EPS board is prepared by using black waste polystyrene foam.The XRD of the black polystyrene beads are characterized.SEM,water absorption,apparent density,bending strength,compressive strength,thermal conductivity,oxygen index and the content of blowing agent of the black polystyrene foam are tested.The economic benefits of different products are analyzed.In this paper,the technology,cost,environmental pollution and other factors are considered.Especially in the light of industrialization the recycling of polystyrene from waste polystyrene is studied by means of “suspension method” and basing on “dissolving polymerization method”.Use common organic reagent and can be recycled,no longer make use of the high cost styrene monomer,which can reduce cost,the simple solvent recovery.Graphite/polystyrene is prepared by solvent blending method compared with in-situ polymerization.The addition of natural flake graphite may have inhibition effect on polymerization in the latter method.Therefore,there is a limit to the graphite content.However,this method without the limit,which is extremely beneficial for industrialization.The recycling of waste black EPS foam can achieve the product with excellent performance,environmental protection and economic purposes.