AN ECO-FRIENDLY UREA-FORMALDEHYDE RESIN: PREPARATION STRUCTURE AND PROPERTIES

The preparation, structures and properties of UF resin prepared with concentrated formaldehyde at a low molar ratio F/U=1.1 were studied in this paper. According to the results obtained from 13 C-NMR, FT-IR and DMA, UF resin prepared with concentrated formaldehyde showed better mechanical properties and heat resistance and lower formaldehyde emission responsible for its high degree of polycondensation and crosslinking than that of UF prepared with common formaldehyde, but its stability was so bad due to its high content of ether bridges. However, it was stated that adding hydrolyzed soy protein to this UF resin at the first alkali preparation stage of “alkali-acid-alkali”, its stability got improved due to the increase of methylene bridges, which was the key contribution to polycondensation. higher content of methylene bridges, degree of polycondensation and crosslinking in S1-UF2 than that of UF2, which might offset instability produced by ether bridges fracture and rearrangement.

[1]  G. Du,et al.  Study on the Soy Protein-Based Wood Adhesive Modified by Hydroxymethyl Phenol , 2016, Polymers.

[2]  G. Du,et al.  A computational study on the reaction mechanism of neutral phenol with formaldehyde in aqueous solution , 2016 .

[3]  G. Du,et al.  Soy-based adhesive cross-linked by melamine–glyoxal and epoxy resin , 2016 .

[4]  H. Lei,et al.  Curing behavior of melamine-urea-formaldehyde (MUF) resin adhesive , 2015 .

[5]  Guofeng Wu,et al.  Hydrolyzed soy protein isolates modified urea–formaldehyde resins as adhesives and its biodegradability , 2015 .

[6]  G. Du,et al.  Competitive formation of the methylene and methylene ether bridges in the urea–formaldehyde reaction in alkaline solution: a combined experimental and theoretical study , 2015, Wood Science and Technology.

[7]  H. Lei,et al.  A dynamic mechanical analysis method for predicting the curing behavior of phenol-formaldehyde resin adhesive , 2015 .

[8]  Guofeng Wu,et al.  The effect of hydrolyzed soy protein isolate on the structure and biodegradability of urea–formaldehyde adhesives , 2015 .

[9]  M. López-Caballero,et al.  Release of volatile compounds and biodegradability of active soy protein lignin blend films with added citronella essential oil , 2014 .

[10]  G. Du,et al.  Specific Solvation Effects on the Formation of Urea Anion in Alkaline Solution , 2014 .

[11]  Zhangkang Wu,et al.  Cross-linked soy-based wood adhesives for plywood , 2014 .

[12]  H. Hasse,et al.  Quantitative and qualitative 1H, 13C, and 15N NMR spectroscopic investigation of the urea–formaldehyde resin synthesis , 2014, Magnetic resonance in chemistry : MRC.

[13]  Sun Enhu.  Synthesis and biodegradation characteristics of urea-formaldehyde resin modified with soy protein , 2014 .

[14]  Guofeng Wu,et al.  Preparation and Properties of Biodegradable Planting Containers Made with Straw and Starch Adhesive , 2013 .

[15]  H. Lei,et al.  Disruption of soy-based adhesive treated by Ca(OH)2 and NaOH , 2013 .

[16]  A. Kandelbauer,et al.  Testing by fourier transform infrared species variation during melamine–urea–formaldehyde resin preparation , 2007 .

[17]  A. Kandelbauer,et al.  Comparative 13C‐NMR and matrix‐assisted laser desorption/ionization time‐of‐flight analyses of species variation and structure maintenance during melamine–urea–formaldehyde resin preparation , 2007 .

[18]  G. Du,et al.  Variation of MUF and PMUF resins mass fractions during preparation , 2006 .

[19]  M. Dunky.  Adhesives based on Formaldehyde condensation resins , 2004 .

[20]  M. Okada.  Chemical syntheses of biodegradable polymers , 2002 .

[21]  S. M. Lee,et al.  Examination of selected synthesis and room‐temperature storage parameters for wood adhesive‐type urea–formaldehyde resins by 13C‐NMR spectroscopy. V , 2001 .

[22]  Moon G. Kim.  Examination of selected synthesis parameters for typical wood adhesive-type urea–formaldehyde resins by 13C-NMR spectroscopy. II , 2000 .

[23]  Moon G. Kim.  Examination of selected synthesis parameters for typical wood adhesive‐type urea–formaldehyde resins by 13C NMR spectroscopy. I , 1999 .

[24]  M. Dunky,et al.  Urea–formaldehyde (UF) adhesive resins for wood , 1998 .

[25]  G. Maciel,et al.  NMR study of the stabilities of urea–formaldehyde resin components toward hydrolytic treatments , 1994 .