Study On Improving The Permeability Of Wood Dyed With Reactive Dyes By Chemical And Biological Pretreatment Method And Its Mechanism

With a bright color and a completed chromatography,excellent in all dyeing-fastness,low price and used conveniently,Reactive dyes are more and more widely applied in the field of wood dyeing.Poplar is a fast-growing artificial wood and very rich in china,So it is an important way to make inferior poplar into valuable ones by wood dyeing to solve the contradiction between the supply and demand on colored furniture made with large-diameter and high-grade wood for its declining sharply.Therefore,improving the permeability of reactive dyes on wood is a key research topic in the application of reactive dyes,a key technology in using wood efficiently and especially one of saving-energy and reducing-emission measures to improve the utilization rate of dyes,to enhance the dyeing effect on wood,and to reduce dyes'concentration in waste water in wood dyeing.With chemical-biological method less equipment investment,high efficiency and less damage on wood,it has become one of hot-spot research in improving the wood of permeability at present.The paper focus on poplar is firstly pretreated separately by NaOH pretreatment,by H2O2 bleaching and by biological enzyme pretreatment,then dyed with Reactive dyes red M-3 BS in the value of exhaustion rate and fixation rate and research on the mechanism of three chemical-biological methods in improving the permeability.The main research as follows:(1)Poplar is pretreated by NaOH,then it is dyed with reactive dyes,The paper makes a research on pretreatment condition such as liquor ratio,temperature,time and NaOH concentration and obtain the optimal poplar pretreated by NaOH.Compared with untreated one,the exhaustion rate is increased by 86.3%and fixation rate is increased by 83.1%in this process.Applying Fourier Transform Infrared Spectrum(FTIR)and Gas Chromatograph-Mass Spectrum(GC-MS)identify component of and detect content of poplar's extract pretreated by NaOH and the research proves that extract is mainly made up of 16 kinds of substances 5(1H)-Azulenone,2,4,6,7,8-8a-hexahydro-3,8--dimethyl-4-(1-methylethylidene)-,(8s-cis)-included.The analysis of Scanning Electron Microscope(SEM),X-Ray Diffraction Meter(XRD),Fourier Transform Infrared Spectrum(FTIR)and Thermal Gravimetry-Differential Scanning Calorimetry(TG-DSC)suggest that NaOH pretreatment can through the pit,increase the gap between duct and duct and between duct and fiber cells,reduce the free water content,improve the permeability of reactive dyes on poplar,and improve the thermal stability of poplar and its density.(2)Poplar is bleached by H2O2,then it is dyed with reactive dyes,and H2O2 bleaching is studied by single factor experiment and response surface optimization research on pretreatment condition such as liquor ratio,temperature,time and H2O2 concentration,obtaining the optimal process.Compared with untreated one,the exhaustion rate is increased by 86.3%and fixation rate is increased by 83.1%in this process.The component of poplar's extract bleached by H2O2 is identified and its content is detected by FTIR and GC-MS,and the study suggests that extract is mainly made up of 13 kinds of substance Tridecanoic acid,methyl ester included and the analysis of SEM,XRD,FTIR and TG-DSC suggest that H2O2 bleaching can eliminate the color of poplar,through the pit,make the process more easier that dyes enter into the internal of poplar and react with fibers,improve the permeability of reactive dyes on poplar,and improve the thermal stability of poplar and its 'density.(3)Poplar is pretreated by enzyme and dyed with reactive dyes.Biological enzyme pretreatment is studied by single factor experiment and response surface optimization researching on pretreatment condition such as liquor ratio,temperature,time,pH and H2O2 concentration and the optimal process is obtained.Compared with untreated one,the exhaustion rate is increased by 77.5%and fixation rate is increased by 73.13%in this process.The component of poplar's extract pretreated by enzyme is identified and its content is detected by FTIR and GC-MS,and The study suggests that extract is mainly made up of 16 kinds of substance including 9,12-Octadecadienoic acid,methyl ester included and the analysis of SEM,XRD,FTIR and TG-DSC suggest that enzyme pretreatment can through the pit and improve poplar's thermal stability and its density.