Preparation And Application Of Lignin-phenol-formaldehyde

Generally,phenol–formaldehyde?PF?resins is synthesized using phenol and formaldehyde under alkaline catalysts.It has excellent water resistance,temperature stability and chemical stability,this make it played an important role in industry application.But the phenol as raw materials is non-renewable petrochemical products,with the economic development the fossil resource shortage and serious environment pollution,searching for renewable energy to replacing petroleum products become a problem urgently need to be solved.Lignin from the residue of xylose containing phenol hydroxyl,alcohol hydroxyl that make it similar to phenol.It has been investigated as a promising alternative substance in phenol-formaldehyde production.The liquid PF can be used as adhesive using in lumber industry decline cost and the solid PF is excellent carbon sources,it has an advantage on preparation of super capacitor energy as storage electrode materials.In this thesis,alkali lignin as material which is extracted from industrial xylose residue,alkali lignin,phenol with formaldehyde reaction in-situ to producing lignin-phenol–formaldehyde?LPF?.The application of LPF in adhesive and storage materials were studied and good results had been achieved.1.Extraction conditions of cornstalk lignin have influence in formaldehyde release,the best extraction conditions is the sodium hydroxide concentration is 5 wt%,the mass ratio of solid/liquid is 1:12,and the reaction time spend 3 h.The minimum formaldehyde release is 0.115%.2.Different lignin extraction conditions,lignin species have the influence to the bonding strength and the performance of the LPF.When the sodium hydroxide concentration is 5 wt%,ratio mass of solid/liquid is 1:8,the reaction time is 4 h and the corncob based-lignin replacement percentage of phenol was 20%,the bonding strength would be max,1.590 MPa.Which is lower than the cornstalk based-lignin with 1.689 MPa.3.Activated carbons were prepared from Lignin-phenol-formaldehyde as the precursors via chemical activation.Controlling the different mass percent of phenol replaced by lignin,activated carbons with controllable structure were formed.Excellent electrochemical performance of a specific capacitor of 322.65 F/g was achieved,when the replacement of lignin is 20%.4.The activation of KOH is superior to Na OH for straw-LPF.The specific capacitor increased with the lignin replacement percentage from 20% to 40%.With KOH the 40% K-LPFC-4 electrode shows good supercapacitors properties with a specific capacitor of 302.8 Fg-1 which is larger than that of 40% N-LPFC-4 with 253.56 Fg^-1.