摘要
【目的】以氟气作为改性剂,利用其较强的渗透性和反应活性与木材细胞形成化学键,达到长效存留和改性竹材的目的。【方法】将4年生的毛竹Phyllostachys edulis置于管式反应器中,通入质量百分比为25%的氟气,在150℃下反应4 h。为了进一步提高氟化效果,先用不同质量分数硫酸预处理竹材,再进行高温氟化处理。【结果】氟化反应主要发生在木质素上。氟化材红外光谱说明氟化处理材在739 cm-1处产生了表征碳氟键(C—F)的新峰,浓硫酸预处理氟化竹材在878和1088 cm-1出现木质素苯环氟多取代(C—Fn)吸收峰。X射线光电子能谱中结合能为687.8 eV的C—F特征峰和689.2 eV的C—F2特征峰证实了氟化处理竹材中C—Fn键的生成。热氟化试块在3次吸湿-干燥和吸水-干燥循环中平均抗胀率分别为19.1%和7.5%。硫酸预处理能进一步提高氟化材的尺寸稳定性,其中20 g·kg^-1的硫酸预处理氟化材效果最为显著,平均抗胀率分别达31.0%和15.8%。防霉测试显示氟化处理材对木霉Trichoderma viride、青霉Penicillium citrinum和黑曲霉Aspergillus niger混合霉菌的抑制效果不明显,硫酸预处理后的氟化材防霉性能有所增加。【结论】竹材气相热氟化能对竹材内部进行改性,处理后的竹材尺寸稳定性和防霉性能均优于未处理竹材。利用氟气对竹材进行气相改性是一种渗透性强、反应活性高的竹材改性新技术。
[Objective]The strong permeability and reactivity of gaseous fluorine supposedly helps form chemical bonds between fluorine and bamboo.This aim is to increase the leaching resistance of gaseous fluorine[Method]The four-year-old bamboo(Phyllostachys edulis)was heated in a tubular reactor at 150℃and treated with 25%fluorine for 4 h.To improve the fluorination effect,bamboo was pretreated with sulfuric acid at different concentrations before the fluorine thermo treatment.Analysis included fourier transformed infrared spectra and X-ray photoelectron spectroscopy.Tests on mold resistance for fluorinated bamboo with mixed fungi of Trichoderma viride,Penicillium citrinum,and Aspergillus niger were conducted.[Result]The chemical analysis and testing of fluoride bamboo showed obvious changes in lignin.Fourier transformed infrared spectra demonstrated that the new peaks at 739 cm-1 were C—F(carbon-fluorine)monosubstituted bonds;whereas,concentrated sulfuric acid pretreated fluorinated bamboo showed double C—F peaks at 878 and 1088 cm-1 caused by the polysubstitution of C—F bonds on the benzene ring of lignin.Binding energies of 687.8 eV(C—F)and 689.2 eV(C—F2)in X-ray photoelectron spectroscopy confirmed the presence of the C—F bond in fluorinated bamboo.The dimensional stability of treated bamboo was tested under three moistening-drying cycles and water soaking-drying cycles,respectively.The average anti-shrink efficiency(ASE)for three cycles of thermo fluorinated bamboo was 19.1%for moistening-drying and 7.5%for water soaking-drying.Sulfuric acid pretreatment further improved dimensional stability of thermo fluorinated bamboo where 20 g·kg^-1 sulfuric acid pretreatment behaved the best with a corresponding ASE of 31.0%for moistening-drying and 15.8%for water soaking-drying.Tests on mold resistance for fluorinated bamboo with mixed fungi of T.viride,P.citrinum,and A.niger,showed no obvious anti-mold efficacy;whereas,for fluorinated bamboo pretreated with sulfuric acid there was slight improvement.[Conclusion
作者
刘庭菘
王慧
王同属
姜俊
王婕
孙芳利
杨先金
LIU Tingsong;WANG Hui;WANG Tongshu;JIANG Jun;WANG Jie;SUN Fangli;YANG Xianjin(School of Engineering,Zhejiang A&F University,Hangzhou 311300,Zhejiang,China;School of Chemistry and Molecular Engineering,East China University of Science and Technology,Shanghai 200237,China)
出处
《浙江农林大学学报》
CAS
CSCD
北大核心
2020年第2期350-356,共7页
Journal of Zhejiang A&F University
基金
国家自然科学基金面上基金资助项目(31470587)
浙江省自然科学基金重点资助项目(Z14C160009)。
关键词
木材科学与技术
竹材
气相氟化
尺寸稳定性
防霉性能
wood science and technology
bamboo
gaseous phase fluorination
dimensional stability
mold resistance
