Full-Text Search:
Home|Journal Papers|About CNKI|User Service|FAQ|Contact Us|中文
《Journal of Beijing Forestry University》 2009-04
Add to Favorite Get Latest Update

Urea-formaldehyde resin modified by nano-TiO_2 under ultrasonic treatment

XIA Song-hua;LI Li;LI Jian-zhang.College of Materials Science and Technology,Beijing Forestry University,100083,P.R.China.  
In order to decrease free formaldehyde of urea-formaldehyde(UF) resin and therefore to lower the formaldehyde emission level of its products,UF resin was modified by adding nano-TiO_2 and applying ultrasonic dispersing technology.Effects of ultrasonic frequency and addition amount of nano-TiO_2 on viscosity,curing rate,free formaldehyde content of UF resin,formaldehyde emission level and bond strength of plywood with this kind of resin were evaluated.The results showed that viscosity and curing rate were affected by ultrasonic frequency and addition amount of nano-TiO_2 indistinctively;when ultrasonic frequency was 28 kHz and the addition amount of nano-TiO_2 was 0.05% of UF resin solid content,compared with normal UF resin,free formaldehyde content of modified UF decreased by 77.8%,bond strength of plywood enhanced about 155% and formaldehyde emission level of plywood with this kind of resin decreased by 68.3%.(~(13)C-NMR) analysis indicated that Uron-CH_2-Uron structure was found in modified UF resins.
【Fund】: “948”国家林业局引进项目(2006-4-107);; 北京林业大学研究生自选课题基金项目(06jj111)
【CateGory Index】: TQ433.431
Download(CAJ format) Download(PDF format)
CAJViewer7.0 supports all the CNKI file formats; AdobeReader only supports the PDF format.
©2006 Tsinghua Tongfang Knowledge Network Technology Co., Ltd.(Beijing)(TTKN) All rights reserved