Semi-liquefied bamboo modified urea-formaldehyde resin to synthesize composite adhesives

Author(s):  
Hongxia PU ◽  
Kaixiang HAN ◽  
Rui DAI ◽  
Zhihua SHAN
Author(s):  
Shanfeng Xu ◽  
Sanshan Xia ◽  
Yuzhu Chen ◽  
Hui Xiao ◽  
Maoyu Yi ◽  
...  

RSC Advances ◽  
2021 ◽  
Vol 11 (40) ◽  
pp. 25010-25017
Author(s):  
Li Lu ◽  
Yan Wang ◽  
Tianhua Li ◽  
Supeng Wang ◽  
Shoulu Yang ◽  
...  

Reactions between CaCO3 and CH2O2 during polycondensation of UF resin produce Ca2+. Ionic bond complexation binds Ca2+ with UF resin. The UF resin crystalline percentage decreases from 26.86% to 22.71%. IB strength of resin bonded fiberboard increases from 0.75 to 0.94 MPa.


2018 ◽  
Vol 40 (4) ◽  
pp. 1287-1294 ◽  
Author(s):  
Vojislav Jovanović ◽  
Suzana Samaržija‐Jovanović ◽  
Branka Petković ◽  
Zoran Milićević ◽  
Gordana Marković ◽  
...  

2020 ◽  
Vol 1001 ◽  
pp. 61-66
Author(s):  
Shan Feng Xu ◽  
San Shan Xia ◽  
Yu Zhu Chen ◽  
Hui Xiao ◽  
Ming Wei Jing ◽  
...  

In this study, Thermogravimetry (TG) were used to analyze thermal degradation properties of two kinds of low-molar ratio of the melamine-modified urea-formaldehyde resin (MUF). The MUF was calculated using Kissinger equation and Flynn-Wall-Ozawa equation Resin pyrolysis activation energy. The results showed that the curing time of low mole was longer than that of MUF resin (muf-b), the content of free formaldehyde was lower, and the formaldehyde emission and wet bonding strength of plywood were reduced by 65.79% and 21.90%, respectively. TG test showed that the pyrolysis process of MUF resins with different molar ratios can be divided into three stages: dehydration, rapid pyrolysis and carbonization. At the same heating rate, the weight loss rate, peak conversion rate and carbon residue of the high molar ratio MUF resin (MUF-a) in the fast pyrolysis stage are larger than those of the MUF-b resin. The MUF-a resin pyrolysis activation energy is 166.76 kJ/mol, and the MUF-b resin pyrolysis activation energy is 95.30 kJ/mol. High molar ratio resin has higher pyrolysis activation energy and better thermal stability.


2011 ◽  
Vol 71-78 ◽  
pp. 3170-3173
Author(s):  
Ji Zhi Zhang ◽  
Xiao Ying Liu ◽  
Ying Ying Qiu ◽  
Xiao Mei Wang ◽  
Jian Zhang Li ◽  
...  

Urea-formaldehyde resin was modified by a modifier with different synthetic processes labelled as UFM1, UFM2, and UFM3 respectively. As a comparison, normal UF resin with a F/U molar ratio of 1.1 labelled as UF0 was synthesized. The thermal behavior of modified urea-formaldehyde resins was studied by TG-DTA techniques, and the properties of plywood bonded with the UFM resins were investigated. The conclusions were as follows: (1) the modifier used in this study could significantly reduce the free formaldehyde content of urea-formaldehyde resin and the formaldehyde emission of plywood; (2) The exothermic peak temperatures of DTA curve were 129.37, 125.05, 120.98, and 116.11 °C for UF0, UFM1, UFM2, and UFM3 respectively. (3) The plywood manufactured with UFM2 and UFM3 resins have high bonding strength (1.28MPa and 1.59MPa) and low formaldehyde emission value (E1 grade).


2010 ◽  
Vol 113-116 ◽  
pp. 1787-1791 ◽  
Author(s):  
Jiu Yin Pang ◽  
Chuan Sun ◽  
Shi Cheng Zhang ◽  
Hai Xing Cui

As the main adhesive types in wood-based panel industry,urea-formaldehyde has such shortcomings as high levels of free formaldehyde content and formaldehyde emission of its bonding product. In this experiment, we try to modify urea-formaldehyde resin with keratin through copolymerization reaction. Through the determination of such reaction technology as molar ratio, adding sequence of keratin and adding amount of keratin, we finally synthesized the low toxic urea resin. The results show that the optimum molar ratio is 1.3:1, the adding amount of keratin is 5% and adding keratin after the third feeding of urea is the best choice. By optimizing the synthesis process, we ultimately get the low toxicity modified urea-formaldehyde resin. At the same time, modified urea-formaldehyde resin cost has been reduced because extensive sources of keratin and low cost.


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