Modified Nanocrystalline Cellulose Used for Improving Formaldehyde Emission and Bonding Strength of Urea Formaldehyde Resin Adhesive

2013 ◽  
Vol 562-565 ◽  
pp. 846-851
Author(s):  
Hao Zhang ◽  
Ying She ◽  
Shu Ping Song ◽  
Jun Wen Pu
Keyword(s):  
Bonding Strength ◽  
Urea Formaldehyde ◽  
Formaldehyde Emission ◽  
Nanocrystalline Cellulose ◽  
National Standards ◽  
Control Group ◽  
Formaldehyde Resin ◽  
Hydroxyl Groups ◽  
Resin Adhesive ◽  
Uf Resin

Nanocrystalline cellulose (NCC) was used for improving the formaldehyde (HCHO) emission and bonding strength of urea formaldehyde (UF) resin adhesive in fiberboard and plywood. The original NCC was modified by 3-aminopropyltriethoxysilane (APTES) and the wetting property with UF resin adhesive was improved by 26.4%. The UF resin adhesive with modified NCC was characterized by X-ray powder diffraction (XRD), thermogravimetric analysis (TG) and Fourier transform infrared (FT-IR). The crystal region of UF resin adhesive was influenced by NCC and the diffraction intensity of the peak at 2θ = 22.82° was enhanced significantly. The thermal stability of UF resin adhesive with 1.0% modified NCC increased by 4.9%. And modified NCC led hydroxyl groups into the UF resin adhesive. HCHO emission and bonding strength of the UF resin adhesive with modified NCC were tested according to Chinese National Standards GB/T 17657-1999 and GB/T 9846-2004. The HCHO emission of fiberboard and plywood with 1.5% modified NCC decreased by 13.0% and 53.2%, respectively. The bonding strength of fiberboard increased by 158.3% (from 0.12 MPa of control group to 0.31 MPa of fiberboard with 1.5% modified NCC), while 1.5% modified NCC led to a 23.6% increase in the plywood.

The Impact of Different Dosage of Additives on the UF Resin Used in Plywood

2011 ◽  
Vol 197-198 ◽  
pp. 147-150 ◽  
Author(s):  
Wei Wang ◽  
Li Bin Zhu ◽  
Ji You Gu ◽  
Xiang Li Weng ◽  
Hai Yan Tan
Keyword(s):  
Urea Formaldehyde ◽  
Formaldehyde Emission ◽  
Urea Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Synthetic Process ◽  
Resin Adhesive ◽  
Environmental Friendly ◽  
Uf Resin ◽  
Comprehensive Performance ◽  
The Impact

Through the study of the effects of different dosage of additives on the properties of urea formaldehyde resin adhesive prepared at low mole ratio of formaldehyde/urea, optimize the synthetic process of the UF resin which is used at the E0 grade plywood. The results showed that the product synthesized under the following condition: the mole ratio of formaldehyde/urea is 0.99:1, the dosage of the specific additive is 1.0% and that of melamine is 3-4%, had a good comprehensive performance and the formaldehyde emission of the plywood meets the E0 grade which is environmental-friendly.

Study on Synthetic Process of Low Toxic Urea-Formaldehyde Resin

2012 ◽  
Vol 621 ◽  
pp. 79-82
Author(s):  
Gui Hua Chen ◽  
Jian Han ◽  
Xiao Huan Zhang
Keyword(s):  
Bonding Strength ◽  
Ph Value ◽  
Urea Formaldehyde ◽  
Formaldehyde Emission ◽  
Urea Formaldehyde Resin ◽  
Experimental Results ◽  
Formaldehyde Resin ◽  
Synthetic Process ◽  
Resin Adhesive ◽  
Low Toxic

This study aimed at exploring a producing method of urea-formaldehyde resin that contained low free formaldehyde. Effects of the pH value of addition stage, the pH value and the temperature of polycondensation stage on the properties of the resin were analyzed. The experimental results showed that controlling the pH value of addition stage to 7.5-8.0, regulating the pH value of polycondensation stage to 4.8-5.1, and keeping the temperature of polycondensation stage to 88-92°C, a low toxic urea-formaldehyde resin adhesive was obtained which contained free formaldehyde 0.08%. Using this resin adhesive, the bonding strength of the plywood reached 1.7MPa, formaldehyde emission of the plywood was 0.7mg/l, reaching the grade E1.

scholarly journals Effects of dilute acid activation and tannin modification on the binding mechanism of formaldehyde-free particleboards

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 6165-6180
Author(s):  
Feng Chen ◽  
Baichuan Wang ◽  
Xinghua Xia
Keyword(s):  
Nitric Acid ◽  
Bonding Strength ◽  
Urea Formaldehyde ◽  
National Standards ◽  
Modulus Of Rupture ◽  
Formaldehyde Resin ◽  
Hydroxyl Groups ◽  
Acid Activation ◽  
Synthesis Mechanism ◽  
Surface Bonding

The development of a formaldehyde-free wood-based panel is a major research direction in the wood-based material industry. Previous research has demonstrated that nitric acid activated fibers and coupling agents could be utilized to manufacture formaldehyde-free medium-density fiberboards. Herein, based on the chemical characteristics of wood, nitric acid and tannin were applied in formaldehyde-free particleboard, featuring suitable mechanical properties and water absorption resistance. The results of modulus of rupture (MOR), surface bonding strength, internal bonding strength, and 2 h moisture thickness swelling (TS) of formaldehyde-free particleboard (that was synthesized at optimal conditions and satisfied the China National Standards GB/T 4897 (2015) and GB/T 17657 (2013)) are discussed. The investigation of the technological conditions on bond performance showed that when the particleboard was bonded with the conditions of 20/80 nitric acid/particles mass proportion, 50% tannin concentration, and 135 °C temperature, the MOR, surface bonding strength, inner bonding strength, and 2 h TS were better than that of the particles with urea formaldehyde resin adhesive. The synthesis mechanism was studied by both Fourier transform infrared spectroscopy and wide-angle X-ray diffraction, and the chemical composition indicated polycondensation of furfural and tannin, and hydrogen bonding of hydroxyl groups as the reaction mechanism between nitric activation and the tannin coupling agent.

Preparation and Formaldehyde Emission and Bonding Performance of Novel Modified Urea-Formaldehyde Resin Adhesive

2012 ◽  
Vol 490-495 ◽  
pp. 3476-3480 ◽  
Author(s):  
Zhen Zhong Gao ◽  
Chao Yue ◽  
Hai Bo Cao ◽  
Xiao Bo Wang ◽  
Xiao Feng Zhu ◽  
...  
Keyword(s):  
Bonding Strength ◽  
Adhesive Bonding ◽  
Urea Formaldehyde ◽  
Formaldehyde Emission ◽  
Urea Formaldehyde Resin ◽  
Molar Ratio ◽  
Formaldehyde Resin ◽  
Resin Adhesive ◽  
Bonding Performance ◽  
Addition Level

Low formaldehyde emission and high bonding strength were two basic criterions of a good urea-formaldehyde resin adhesive (UFRA). In our study, melamine modified methylolurea solution (MUS), was synthesized and used as modifier for UFRA. The bonding strength and formaldehyde emission of urea-formaldehyde resin adhesives(UFRA) were influenced by some factors such as F/U molar ratio of the main resin, F/U molar ratio of modifier, melamine content, mixing ratio of main resin with modifier, which were investigated by a series of single-factor experiments. The results showed that the best adhesive bonding strength of UFRA was 0.93MPa and the lowest formaldehyde emission was 0.43mg / L, when F/U molar ratio of the main resin was 1.5, F/U molar ratio of the MUS was 0.5, the mass fraction of melamine addition level was 5wt.% of MUS, and the mixing mass ratio of methylolurea solution (MUS) to the main UF resin was 20:80.

scholarly journals Calcium carbonate modified urea–formaldehyde resin adhesive for strength enhanced medium density fiberboard production

RSC Advances ◽  
2021 ◽  
Vol 11 (40) ◽  
pp. 25010-25017
Author(s):  
Li Lu ◽  
Yan Wang ◽  
Tianhua Li ◽  
Supeng Wang ◽  
Shoulu Yang ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Urea Formaldehyde ◽  
Medium Density Fiberboard ◽  
Urea Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Medium Density ◽  
Ionic Bond ◽  
Resin Adhesive ◽  
Uf Resin ◽  
Modified Urea

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.

scholarly journals The Impact of Nanoparticles and Moisture Content on Bonding Strength of Urea Formaldehyde Resin Adhesive

2018 ◽  
Vol 69 (3) ◽  
pp. 247-252
Author(s):  
Timuçin Bardak ◽  
Eser Sozen ◽  
Kadir Kayahan ◽  
Selahattin Bardak
Keyword(s):  
Moisture Content ◽  
Bonding Strength ◽  
Urea Formaldehyde ◽  
Urea Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Resin Adhesive ◽  
The Impact

scholarly journals Reduction of formaldehyde emission from urea-formaldehyde resin with a small quantity of graphene oxide

RSC Advances ◽  
2021 ◽  
Vol 11 (52) ◽  
pp. 32830-32836
Author(s):  
Kazuki Saito ◽  
Yasushi Hirabayashi ◽  
Shinya Yamanaka
Keyword(s):  
Graphene Oxide ◽  
Urea Formaldehyde ◽  
Formaldehyde Emission ◽  
Urea Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Uf Resin

This is the first experiment to demonstrate that GO effectively prevents formaldehyde emission from UF resin.

scholarly journals Urea Formaldehyde Resin Resultant Plywood with Rapid Formaldehyde Release Modified by Tunnel-Structured Sepiolite

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1286 ◽  
Author(s):  
Li ◽  
Gao ◽  
Xia ◽  
Li ◽  
Zhou
Keyword(s):  
Shear Strength ◽  
Fracture Surface ◽  
Cross Section ◽  
Urea Formaldehyde ◽  
Formaldehyde Emission ◽  
Formaldehyde Resin ◽  
Tunnel Structure ◽  
Formaldehyde Release ◽  
Uf Resin ◽  
The Cost

In order to reduce the cost of plywood and save edible resources (wheat flour), a cheap and resourceful clay, sepiolite, was used to modify urea formaldehyde (UF) resin. The performances of filler-filled UF resins were characterized by measuring the thermal behavior, cross section, and functional groups. Results showed that cured UF resin with SEP (sepiolite) formed a toughened fracture surface, and the wet shear strength of the resultant plywood was maximum improved by 31.4%. The tunnel structure of SEP was beneficial to the releasing of formaldehyde, as a result, the formaldehyde emission of the plywood bonded by UF resin with SEP declined by 43.7% compared to that without SEP. This study provided a new idea to reduce the formaldehyde emission, i.e. accelerating formaldehyde release before the product is put into use.

Performances of Modified Urea-Formaldehyde Resins for Bonding Plywood

2011 ◽  
Vol 71-78 ◽  
pp. 3170-3173
Author(s):  
Ji Zhi Zhang ◽  
Xiao Ying Liu ◽  
Ying Ying Qiu ◽  
Xiao Mei Wang ◽  
Jian Zhang Li ◽  
...  
Keyword(s):  
Urea Formaldehyde ◽  
Formaldehyde Emission ◽  
Exothermic Peak ◽  
Urea Formaldehyde Resin ◽  
Molar Ratio ◽  
Formaldehyde Resin ◽  
Formaldehyde Content ◽  
Uf Resin ◽  
Dta Curve ◽  
Modified Urea

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).

The Utilization of Phenol Components in Bio-Oil for Modifying Urea-Formaldehyde Resin Adhesive

2015 ◽  
Vol 1096 ◽  
pp. 209-213
Author(s):  
Yi Cheng ◽  
Qi Kui Tian ◽  
Rui Li
Keyword(s):  
Reaction Mechanism ◽  
Organic Acid ◽  
Urea Formaldehyde ◽  
Formaldehyde Emission ◽  
Solid Content ◽  
Formaldehyde Resin ◽  
Uf Resin ◽  
Bio Oil ◽  
Ft Ir ◽  
Addition Amount

The components in bio-oil are mainly concluding organic acid, aldehydes and phenolics. As the irregular cracking of the pyrolysis, the products are complex and difficult to separate. A comprehensive concept was presented and the extractions from bio-oil were used for modifying urea-formaldehyde (UF) resin in this study. Characterization by FT-IR and GC-MS indicated that the reaction mechanism. Phenol-oil addition amount and particle boards test were investigated resulted those 10% phenol-oil shows the best properties: viscosity of 73.36 mm/s, solid content of 52.25% and pH of 8.35 and the best pressing condition is 125°C for 5min which produce a 1.23MPa bond strengthen and 1.05 mg/L formaldehyde emission plywood.

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