碱木素改性酚醛树脂胶粘剂的合成及应用研究

关键词：碱木素：酚醛树脂；，木材胶黏剂AbstractLignin is a natural organic polymer and renewable resources,it's content of ligninsecond only to cellulose in plants.Due to the serious resource crisis,more and more attentionwere paid to study and application of lignin and its derivatives.With the development oftimber industry,Adhesive industry in China has also been great development.Wood adhesiveproducts for industrial,whether in production or the number of varieties,or in product quality,all have a lot of progress,but also existent some problems.Phenolic resin(phenol-formaldehyde resin hereinafter referred to as PF)as an widelyused and good performance polymer resin in preparing boards and panels industry,it hasstrong adhesive ability,good weather-resistant and waterproof characteristics,but the highcost and non-renewable sources of raw materials shortcomings also existent.Because of thealkali lignin from the pulp and paper waste water main,the application of alkali lignin inalkali lignin-phenol-formaldehyde resin(ALPF)can not only reduce the cost of manufacture,but also decrease environmental pollution,so have greater economic and social significance.Firstly,the chemical structure of lignin were analyzed by IR and elemental analysis,alkalinelignin has large amount of phenolic hydroxyl.part of alcohol hydroxyl,so it is suitable tosynthesize lignin-based phenol formaldehyde resin.Secondly,as the reaction time,reaction temperature,wood/aldehyde ratio,pH and otherperformance parameters on free formaldehyde reactions and the methylol content,from theparameter of the free formaldehyde reactions and the methylol content decided the optimalconditions for modification of hydroxymethyl:90℃、pHll.5、reaction time is3.5h、wood/aldehyde ratio is 4:1.As this optimal conditions,the content of hydroxymethyl is thehightest and from the hydroxymethyl increasing effectively raising the lignin reactivity withformaldehyde.At the same time,optimized not only reduce the free formaldehyde content,but also to the efficient use of resources and environmental protection.The last,for alkali lignin replace 50%phenol to compound ALPF,discussed the amountof alkali,formaldehyde and urea performance of these free formaldehyde free phenol.viscosity and adhesive strength index From the study,when the alkali content of 4.5%2