Research On Decay Resistance Of Reconsolidated Square Materials Of Cotton Stalk

Reconsolidated square materials of cotton stalk is a new artificial biomass material,and its performance is close to solid wood that can replace the wooden material used in furniture,building and packaging industries,which is a new direction of cotton stalk material application.The easy absorption and decayed performance will also have an impact on the decay resistance of reconsolidated square materials of cotton stalk.Therefore,the research of its decay resistance can lay the foundation for its generalization and application.This paper takes cotton stalk as material,uses PF and MDI as the adhesive respectively with resin content of 8%,10% and12%,and prepares the reconsolidated square materials of cotton stalk by orthogonal experimental method as research object,which firstly studies different resistant performances of the wood-rotting fungi for the timber.Then,it uses ACQ preservative to immerse the cotton stalk recombining timber,and analyzes the influence of preservative concentration and drug loading rate on its performance,which obtaining the optimal preservative treatment solution.The major results are as below:(1)Reconsolidated square materials of cotton stalk without preservative treatment is in weight loss rate of 24.6%~32.9% through wood rot fungi decaying.Both of the weight loss rates are between 25%~44% that belong to slight decay resistant level,which proofs that resistance of reconsolidated square materials of cotton stalk has poor decay resistance.(2)When the adhesives are the same,the large the resin content,the smaller the weight losses of resistance of reconsolidated square materials of cotton stalk,and the better of its decay resistance.Resistance of reconsolidated square materials of cotton stalk's weight loss rate in white rot fungi decaying is always larger than the weight loss rate in brown rot fun decaying.That means resistance of reconsolidated square materials of cotton stalk's decay resistance of white rot fungi is worse than its decay resistance of brown rot fungi.For certain resin content and wood-rotting fungi,MDI resistance of reconsolidated square materials of cotton stalk's weight loss rate is always smaller than the mass loss rate with PF.That means MDI reconsolidated square materials of cotton stalk's decay resistance is better than its decay resistance for PF reconsolidated square materials of cotton stalk.(3)The same type of adhesives and resin content on reconsolidated square materials of cotton stalk through ACQ preservative treatment,when the preservative concentration isconstant,as drug loading rate increasing,the weight loss rate of reconsolidated square materials of cotton stalk reduces;and reconsolidated square materials of cotton stalk's decay resistance raises as the preservative drug loading rate increases;When preservative's drug loading rate is constant,as the preservative concentration increasing,the weight loss rate of reconsolidated square materials of cotton stalk reduces,and its decay resistance is largely improved as preservative concentration increases.(4)For MDI reconsolidated square materials of cotton stalk,when the resin content reaches 8% and 10%,preservative concentration is 7%,drug loading is 10 kg/m3,the weight loss rate in white rot fungi and brown rot fungi are 24.3%,23.3% and 22.7%,22.0%,its decay resistance level reaches decay resistance;When the resin content is 12%,and under experimental treatment condition,except for the specimen with 3% preservative concentration and 5kg/m3~7.5 kg/m3 drug loading,the other type specimen' decay resistance are all the decay resistant level.For PF reconsolidated square materials of cotton stalk,when the resin content is 10%,preservative concentration is 7%,and drug loading is 10kg/m3,the weight loss rate is 24.3%,its decay resistance reaches decay resistance level.When the resin content is 12%,preservative concentration is 3%-5%,drug loading rate is 10kg/m3;and when the preservative concentration is 7%,and drug loading rate is 7.5 kg/m3~10 kg/m3,the weight loss rate are 21.4%~23.8%,its decay resistance reaches decay resistance level.(4)In wood-rotting fungi decaying of the cotton stalk recombining timber,the three parameters of resin content,preservative concentration and preservative drug loading rate have different influence degree on decay resistance of the cotton stalk recombining timber.For white rot fungi,the influence degree order is resin content>preservative drug loading>preservative concentration;For brown rot fungi,the influence priority order is resin content>preservative concentration>preservative drug loading.