Effect Of Bio-oil Components On Formaldehyde Emission Of Phenol-Formaldehyde Resin Modified By Bio-oil For Wooden Heating

The problem of indoor formaldehyde pollution caused by radiant heating wooden flooring has attracted much attention.The root cause of formaldehyde emission from wooden flooring lies in the formaldehyde resins it uses.Compared with phenol-formaldehyde resins,bio-oil phenol-formaldehyde resins(BPF resins)have similar physical and chemical properties and lower raw material costs and formaldehyde emissions,making them potentially ideal choices for floor heating wooden flooring resins.During the synthesis of BPF resin,bio-oil components react with the phenol-formaldehyde resin system to affect the formaldehyde emission.However,there has been no research on the effect of bio-oil components on the formaldehyde emission of BPF resin,making it is difficult to reasonably adjust bio-oil components to obtain BPF resins with lower formaldehyde emission.In this paper,the effect of the ratio of phenol substituted by bio-oil on the formaldehyde emission of BPF resin was explored,the ratio of phenol substituted by bio-oil with low formaldehyde emission was optimized;The bio-oil model compounds with different composition were prepared by the model compound method,and the bio-oil model compound phenol-formaldehyde resin was synthesized,the effects of various components of bio-oil on the formaldehyde emission of BPF resin and plywood under radiant floor heating its formaldehyde emission were investigated.The main conclusions of this paper are as follows:(1)The optimal ratio of bio-oil to replace phenol in BPF resin is 20%,and the formaldehyde emission at this time is 0.297 mg/L.(2)Phenols,ketones,aldehydes and sugars can reduce the formaldehyde emission of the BPF resin,and the acid components have the opposite effect;phenols,ketones,aldehydes and sugar components promote the polycondensation and cross-linking reaction of BPF resin,and acid components are not conducive to the resin polycondensation and cross-linking.(3)Phenols and aldehydes can reduce the effect of temperature increase on the formaldehyde emission of plywood with BPF resin;phenols,ketones,aldehydes,and sugars can shorten the time for the formaldehyde emission to reach equilibrium,and the shortening effect of ketones is the weakest;phenols,ketones,aldehydes,and sugars can inhibit formaldehyde emission of plywood with BPF resin under radiant floor heating,and acid components have the opposite effect;the initial formaldehyde emission of plywood with bio-oil model compound phenol-formaldehyde resin under radiant floor heating is mainly the free formaldehyde remaining in the plywood,and the subsequent formaldehydeemission was caused by the rupture of the ether bond;the addition of phenols,ketones,aldehydes and sugars can reduce the formaldehyde emission from the rupture of ether bonds,while the acid components have the opposite effect.