多元酸类化合物与木材交联反应机理研究

Polycarboxylic acids acted as esterification agents and inorganic salts and aromatic N-heterocyclic compounds acted as catalyst in the research of wood crosslinking reaction. This soluble crosslinking system is non-formaldehyde, poison free and pollution free system.。This projec studied systematically crosslinked action, reaction mechanism and catalyst process using spectrums of Solid Nuclear Magnetic Resonance Spectroscopy-CP/ MAS 13C NMR、Fourier Transform Infrared Sppectroscopy-FTIR and X-ray PHotoelectron Spectroscopy-ESCA, on the base determined some pHysics properties and explored application in functionality modify of wood. .FTIR, CP/MAS 13C NMR spectroscopy favored: esterification reaction between polycarboxylic acid and wood components occurred at elevated temperature with catalyst NaH2PO2. Overlap bands were separated, main bands of cellulose, lignin and wood meal were signed, and three parameters of esterification reaction were defined in FTIR spectra, which are esterification degree, carbonyl ratio and crosslinkage degree. Therefore esterification crosslinked reaction between polycarboxylic acid and wood can quantitatively indicate. Experiments show that Polycarboxylic acids can wood crosslinking esterification agents and sodium hypopHospite（NaH2PO2）is obvious in catalyst effect..The crosslinking reactions between polycarboxylicacid and wood go through a mechanism of two steps reaction process, the first five cyclic anhydrides are formed as intermediates by dehydrating between hydroxyls in polycarboxylic acids, second esters are occurred by nucleopHilic substitution reaction between wood hydroxyls and cyclic anhydrides. This goes not through four sides intermediates by dehydrating between carboxylic and alcohol. The esterification process of a reversible step is resolved as two irreversible steps, then chemical decomposition of wood components were decreased in liquid acid catalyst.。Antiswelling efficiency（ASE） and vibrancy efficiency were distinctly improved，moisture excluding efficiency (MEE) was little changed in crosslinking wood by Polycarboxylic acids, the reason may be moisture absorption by carboxyl no reaction..In this work, wood crosslinking system that is non-formaldehyde and poison free was analysed and evaluated, therefor it provided scientific theory bases in order to make use of wood with reason and high efficiency and establish project of functionality modify about wood..

以多元羧酸为酯化剂、无机盐等为催化剂，采用现代波谱技术探索用于木材交联反应的无毒害、水溶性的非甲醛系试剂、改变催化作用过程及揭示交联剂与木材反应机理，筛选有效催化剂和多元羧酸及复配试剂，进行木材功能性改良的应用研究。对提高我国木材科学理论研究水平和探索新型交联剂的应用，促进学科交叉外延具有重要的科学价值和实际意义。