scholarly journals Study on the Pyrolysis Behaviors of Urea-Formaldehyde Resin and Rice Straw Mixed Pellets

2022 ◽  
Vol 9 ◽  
Author(s):  
Xiaoteng Li ◽  
Huilin Bing ◽  
Siyi Luo ◽  
Weiwei Zhang ◽  
Zongliang Zuo ◽  
...  
Keyword(s):  
Activation Energy ◽  
Rice Straw ◽  
Urea Formaldehyde ◽  
Liquid Product ◽  
Urea Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Mass Ratio ◽  
Pyrolysis Process ◽  
Pyrolysis Kinetics ◽  
Uf Resin

In order to study the effect of biomass on the pyrolysis characteristics of urea-formaldehyde resin, the thermogravimetric experiments were carried out respectively using urea-formaldehyde resin (UF), rice straw (RS), and their mixed pellets with different proportions. The pyrolysis kinetics analysis was conducted. The results showed that the pyrolysis process of UF resin and mixed pellets could be divided into three stages: the drying and dehydration of the material, the rapid decomposition of volatile matter, and residue decomposition. The reaction order of UF resin and mixed pellets was discussed using the Coats–Redfern method, the activation energy of UF resin was 54.27 kJ/mol, and this value decreased with the addition of rice straw. As the mass ratio of UF resin to rice straw was 3:1, the activation energy achieved the lowest value, which means that the addition of rice straw was beneficial to the pyrolysis process of UF. In the process of pellet preparation, the falling strength and compressive strength of UF resin pellets can be improved by adding an appropriate proportion of rice straw. In this test, the yield of pyrolytic carbon reached the highest value of 23.93%, as the mass ratio of UF resin to rice straw was 3:2. When the mass ratio was 4:1, the highest liquid product yield of 43.21% was achieved.

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.

Preparation and Characterization of Hexadecane Microcapsule Phase Change Materials by In Situ Polymerization

2013 ◽  
Vol 815 ◽  
pp. 367-370 ◽  
Author(s):  
Xiao Qiu Song ◽  
Yue Xia Li ◽  
Jing Wen Wang
Keyword(s):  
Particle Size ◽  
Phase Change ◽  
Phase Change Materials ◽  
In Situ Polymerization ◽  
Urea Formaldehyde ◽  
Agitation Speed ◽  
Urea Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Mass Ratio

Hexadecane microcapsule phase change materials were prepared by the in-situ polymerization method using hexadecane as core materials, urea-formaldehyde resin and urea-formaldehyde resin modified with melamine as shell materials respectively. Effect of melamine on the properties of microcapsules was studied by FTIR, biomicroscopy (UBM), TGA and HPLC. The influences of system concentration, agitation speed and mass ratio of wall to core were also investigated. The results indicated that hexadecane was successfully coated by the two types of shell materials. The addition of melamine into the urea-formaldehyde resin microcapsule reduced microcapsule particle size and microencapsulation efficiency. The influences of factors such as system concentration, agitation speed and mass ratio of wall to core to different wall materials microcapsules presented different variety trends of the microcapsule particle size.

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.

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.

Thermal Behavior Analysis of Melamine Modified Urea-Formaldehyde Resin with Different Molar Ratios

2020 ◽  
Vol 1001 ◽  
pp. 61-66
Author(s):  
Shan Feng Xu ◽  
San Shan Xia ◽  
Yu Zhu Chen ◽  
Hui Xiao ◽  
Ming Wei Jing ◽  
...  
Keyword(s):  
Activation Energy ◽  
Urea Formaldehyde ◽  
Formaldehyde Emission ◽  
Urea Formaldehyde Resin ◽  
Molar Ratio ◽  
Formaldehyde Resin ◽  
Molar Ratios ◽  
High Molar Ratio ◽  
Degradation Properties ◽  
Modified Urea

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.

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).

Study on Urea-Formaldehyde Resin for Glass Wool Products

2013 ◽  
Vol 774-776 ◽  
pp. 1232-1236
Author(s):  
Nan Zhe Zhang
Keyword(s):  
Polyvinyl Alcohol ◽  
Water Resistance ◽  
Urea Formaldehyde ◽  
Glass Wool ◽  
Orthogonal Test ◽  
Urea Formaldehyde Resin ◽  
Molar Ratio ◽  
Formaldehyde Resin ◽  
Resin Adhesive ◽  
Uf Resin

In order to prepare urea-formaldehyde (UF) resin adhesive with good performance for glass wool products, we used polyvinyl alcohol (PVA), p-toluenesulfonamide (PTSA) and methanol to modify UF resin, optimized the molar ratio of formaldehyde (F) / urea (U) and reaction components ratio by orthogonal test, reduced the content of free formaldehyde in UF resin, and enhanced the water resistance, flexibility and stability of UF resin.

Study on Curing Characteristics of Low-Toxicity Urea-Formaldehyde Resin

2011 ◽  
Vol 393-395 ◽  
pp. 1447-1450
Author(s):  
Shu Min Wang ◽  
Jun You Shi
Keyword(s):  
Activation Energy ◽  
Urea Formaldehyde ◽  
Formaldehyde Resin ◽  
Test Results ◽  
Hot Press ◽  
Curing Reaction ◽  
Uf Resin ◽  
Curing Characteristics ◽  
Low Toxicity ◽  
Hot Press Process

Curing characteristics of low-toxicity urea-formaldehyde (UF) resin in different curing system were studied by differential scanning carlorimetry (DSC). Test results showed that the initial orterminal temperature and activation energy needed of curing reaction for low-toxicity UF resin were different in different curing system. The initial temperature of curing reaction for low-toxicity UF resin and activation energy were the lowest, and exotherm was most under curing system C, which showed the acceleration of curing system C on low-toxicity UF resin was best. The appropriate curing system can be optimized and applied for hot-press process in practical production by means of DSC to investigate curing characteristics of low-toxicity UF resin.

scholarly journals Physico-Mechanical and Thermal Properties of Thermoplastic Poly(Vinyl Alcohol) Modified Thermosetting Urea Formaldehyde Resin

2021 ◽  
Vol 21 (4) ◽  
pp. 53-66
Author(s):  
Shahin Sultana ◽  
Mehedi Mannan ◽  
Md. Jaynal Abedin ◽  
Zahidul Islam ◽  
Husna Parvin Nur ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Tensile Properties ◽  
Vinyl Alcohol ◽  
Urea Formaldehyde ◽  
Forest Products ◽  
Urea Formaldehyde Resin ◽  
Poly Vinyl Alcohol ◽  
Formaldehyde Resin ◽  
Mechanical And Thermal Properties ◽  
Uf Resin

Abstract Urea formaldehyde (UF) resins are brittle and to improve their tensile properties poly(vinyl alcohol) (PVA) has been used to modify the UF resin. An easy improved procedure was developed to make PVA modified UF resin on the basis of conventional synthesis of UF resin. Prepolymer of UF was mixed with different weight percentages of PVA (1-5%) to synthesize modified UF resin which can be used to make adhesive for forest products. Both UF and modified UF resins were characterized by FTIR, physico-mechanical and thermal properties analyses. Modified UF resin containing 2 wt. % PVA exhibited better results than the UF.

Influence of a urea–formaldehyde resin adhesive on pyrolysis characteristics and volatiles emission of poplar particleboard

RSC Advances ◽  
2016 ◽  
Vol 6 (16) ◽  
pp. 12850-12861 ◽  
Author(s):  
Y. Zhang ◽  
Z. B. He ◽  
L. Xue ◽  
D. M. Chu ◽  
J. Mu
Keyword(s):  
Urea Formaldehyde ◽  
Urea Formaldehyde Resin ◽  
Wood Waste ◽  
Formaldehyde Resin ◽  
Resin Adhesive ◽  
Pyrolysis Characteristics ◽  
Uf Resin ◽  
Main Components

To investigate the influence of urea–formaldehyde resin (UF resin) adhesive on the thermal utilization of wood waste, the pyrolysis of particleboard and its main components (poplar and UF resin) are studied in this paper.

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