Preparation And Property Research Of PVF Composite Sponge

The preparation of polyvinyl formal sponge is based on polyvinyl alcohol andformaldehyde, and because of its strong absorbent, non-toxic, non-polluting, good toughness,readily biodegradable, good elasticity and other reasons, it is widely used in medical sponges,toiletries, packaging materials, cushioning materials, home, decoration and other industries.No matter how, due to its insulation and flammable, it hinders the application in some specialfields. Therefore, the preparation of the polyvinyl formal retardant antistatic sponge ismeaningful.The purpose of this thesis is the preparation of flame retardant antistatic polyvinyl formalcompound sponge which based on the polyvinyl alcohol and formaldehyde, through the fill ofexpanded graphite, zinc borate and melamine, and with the method of in situ synthesis–foaming.For the purpose of the preparation for polyvinyl formal compound sponge, firstly,we use the method of in situ synthesis-foaming for the preparation of polyvinyl formal spongewith the polyvinyl alcohol and formaldehyde as raw materials, and we characterize themorphology and structure of polyvinyl formal sponge. On this basis, we confirm thepolyvinyl formal sponge has been prepared and it can be prepared by the method of in situsynthesis–foaming. Then, we use the method of in situ synthesis–foaming to prepare thepolyvinyl formal compound sponge with polyvinyl alcohol，formaldehyde，expanded graphite,zinc borate and melamine as raw materials，and we character the morphology and structure ofpolyvinyl formal compound sponge. On the basis of this representation, we confirm thepolyvinyl formal compound sponge has been prepared. In order to achieve the preparation offlame retardant antistatic polyvinyl formal compound sponge, firstly, we investigate thedegree of acetalization, the density and the water absorption of polyvinyl formal sponge andthe density and the water absorption of polyvinyl formal compound sponge. By the comparingmethod, we further confirm that the preparation of polyvinyl formal compound sponge. Then,we investigate the surface resistance value and oxygen index of polyvinyl formal compoundsponge. Through the analysis of the surface resistance value and oxygen index, we furtherconfirm the polyvinyl formal compound sponge has been prepared. Research of entire thesisconsists of the following four aspects. 1) Preparation and characterization of expanded graphiteExpanded graphite is one of the raw materials in the preparation of polyvinyl formalcompound sponge. This thesis, the-100mesh flake graphite, sulfuric acid and potassiumdichromate as reactants, we prepare the-100mesh expanded graphite with chemical oxidationmethod. At the same time, we use SEM character the morphology and structure of expandedgraphite, and confirm that the expanded graphite has been prepared.2) Preparation and characterization of PVF spongePolyvinyl alcohol (1799),40%formaldehyde solution acid as the base material and50%sulfuric acid as the catalyst, the PVF polymer was synthesized through in situ synthesis. Then,mixing the PVF polymer and foaming agent, we prepare the PVF sponge through foaming. Atthe same time, we use IR and JMS character the structure and morphology of PVF sponge,and confirm the PVF sponge has been prepared.3) Preparation and characterization of PVF compound spongePolyvinyl alcohol(1799),40%formaldehyde solution acid as the base material, expandedgraphite, zinc borate and melamine as raw materials and50%sulfuric acid as the catalyst, thePVF compound was synthesized through in situ polymerization. Then, mixing the PVFcompound and foaming agent, we prepare the PVF compound sponge through foaming. Atthe same time, we use IR and JMS character the structure and morphology of PVF compoundsponge, and confirm the PVF compound sponge has been prepared.4) PVF compound sponge performance investigationIn the conditions of different dosage of formaldehyde (reactant) and sulfuric acid(catalyst), we prepare the PVF sponge with the method of in situ synthesis-foaming. At thesame time, we investigated the influence of the dosage of formaldehyde and sulfuric acid tothe degree of acetalization,In the conditions of different dosage of pentane, emulsifier and expanded graphite, weprepare the PVF sponge, expanded graphite and PVF compound sponge with the method of insitu synthesis-foaming. At the same time, we investigated the influence of the dosage ofpentane, emulsifier and expanded graphite to the density and the water absorption.In the conditions of different dosage of expanded graphite, zinc borate, melamine, weprepare the expanded graphite and PVF compound sponge, expanded graphite、zinc borate and PVF compound sponge with the method of in situ synthesis-foaming. At the same time,we investigate the influence of the dosage of expanded graphite, zinc borate, melamine to thesurface resistance value and OI.On the basis of the above work, we find that the in situ polymerization-foamingtechnology can be used for the preparation of PVF compound sponge, at the same time, thePVF compound sponge and PVF sponge all have the character with porous morphology. Inaddition, from the results of the survey of the surface resistance value and OI, we find thatwhen the dosage of the expanded graphite, zinc borate, and melamine are1.00g and0.50gand0.40g, OI of PVF compound sponge reached55.8,61.0and60.0respectively, the surfaceresistance value of PVF compound sponge respectively reached4.13x107Ohms/sq,7.62x107Ohms/sq and6.96x107Ohms/sq. Thus, we conclude that both flame retardant andantistatic performance PVF has been prepared.