Performance of a formaldehyde-free sesame protein adhesive modified by urea in the presence and absence of glyoxal

Sesame cake and meal, byproducts of the sesame oil process industry and mainly used as feed and fertilizer, are often not optimally utilized and are wasted when the material could be used as a high-quality protein source. This research primarily emphasizes the preparation of a sesame protein-based adhesive with urea and glyoxal modification to use as a wood adhesive. The performance and characterization of the urea and glyoxal modified sesame protein adhesive (USP and GUSP, respectively) were measured precisely. After glyoxal was added, the water resistance of the GUSP adhesive was significantly enhanced, reaching the standard for Type II plywood. The formaldehyde emission test showed that the GUSP adhesive could be utilized as a formaldehyde-free wood adhesive, having a significantly lower than the demand of the E0 level (i.e., 0.5 mg/L). Furthermore, increasing the glyoxal content in the adhesives enhanced the thermal stability but not significantly. A substance with a crosslinking structure was formed from the reaction between the sesame protein and glyoxal, which enhanced the water resistance. Meanwhile, the fractured structure of the GUSP adhesive having a compact surface also was propitious to enhance the water resistance. Thus, the GUSP adhesive could be used as a novel adhesive in plywood fabrication.

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Preparation and Characterization of Silicate Wood Adhesive Modified with Ammonium Stearate

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1033-1034.1048 ◽

2014 ◽

Vol 1033-1034 ◽

pp. 1048-1053 ◽

Cited By ~ 1

Author(s):

Xin Li Zhang ◽

Hong Hui Zhang ◽

Yi Qiang Wu ◽

Yun Chu Hu

Keyword(s):

Bonding Strength ◽

Water Resistance ◽

Wood Adhesive ◽

National Standard ◽

Adhesion Properties ◽

Good Thermal Stability ◽

Thermo Gravimetric Analyzer ◽

Infrared Spectrometer ◽

Grade Ii

In order to improve the water resistance of silicate wood adhesive, a kind of silicate adhesive was prepared from water glass with silica as curing agent, and ammonium stearate as modifier. The chemical structure, surface morphology and thermal properties of the silicate adhesive were characterized by Fourier transform infrared spectrometer, scanning electron microscope, and thermo-gravimetric analyzer. As the two main measures of adhesion properties, the bonding strength and water resistance were also determined. The results showed that ammonium stearate was successfully introduced into the molecule structure of silicate, the silicate adhesive have good thermal stability in the range of 30~800 °C and the modified silicate adhesive had more smooth cured morphology. The bonding strength and 24h water absorption rate of poplar plywood glued by the silicate adhesive was 0.71 MPa and 22.81%, respectively, reaching the grade II of plywood performance's national standard.

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Soybean Meal-Based Wood Adhesive Enhanced by Phenol Hydroxymethylated Tannin Oligomer for Exterior Use

Polymers ◽

10.3390/polym12040758 ◽

2020 ◽

Vol 12 (4) ◽

pp. 758

Author(s):

Mingsong Chen ◽

Yi Zhang ◽

Yue Li ◽

Sheldon Q. Shi ◽

Jianzhang Li ◽

...

Keyword(s):

Soybean Meal ◽

Water Resistance ◽

Moisture Absorption ◽

Formaldehyde Emission ◽

Wood Adhesive ◽

Solid Wood ◽

Solid Content ◽

Mass Ratio ◽

Residual Rate ◽

Synthetic Adhesives

Bio-based adhesives have low water resistance and they are less durable than synthetic adhesives, which limits their exterior applications. In this study, a bio adhesive was developed from soybean meal and larch tannin that was designed for exterior use. Phenol hydroxymethylated tannin oligomer (PHTO) was synthesized and then mixed with soybean meal flour in order to obtain a soybean meal-based adhesive (SPA). The results showed that the moisture absorption rate, residual rate, and solid content of SPA with 10 wt % PHTO (mass ratio with respect to the entire adhesive) were improved by 22.8%, 11.6%, and 6.8%, respectively, as compared with that of pure SPA. The wet shear strength of plywood with SPA with 10 wt % PHTO (boiling in 100 °C water for 3 h) was 1.04 MPa when compared with 0 MPa of pure SPA. This met the bond strength requirement of exterior-use plywood (GB/T 9846.3-2004). This improved adhesive performance was mainly due to the formation of a crosslinked structure between the PHTO and the protein and also PHTO self-crosslinking. The formaldehyde emission of the resulting plywood was the same as that of solid wood. The PHTO-modified SPA can potentially extend the applications of SPAs from interior to exterior plywood.

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Preparation and Properties of the Urea-Formaldehyde Res-In/Reactive Halloysite Nanocomposites Adhesive with Low-Formaldehyde Emission and Good Water Resistance

Polymers ◽

10.3390/polym13142224 ◽

2021 ◽

Vol 13 (14) ◽

pp. 2224

Author(s):

Jingbiao Song ◽

Shiwei Chen ◽

Xibin Yi ◽

Xinfu Zhao ◽

Jing Zhang ◽

...

Keyword(s):

Water Resistance ◽

In Situ Polymerization ◽

Chemical Interaction ◽

Low Cost ◽

Urea Formaldehyde ◽

Formaldehyde Emission ◽

Wood Adhesive ◽

Halloysite Nanotubes ◽

Formaldehyde Resin ◽

Sem Images

Low-cost urea formaldehyde resin (UF)/reactive halloysite nanotubes (HNTs) nanocomposite adhesive was prepared successfully via in situ polymerization. The HNTs were modified to improve its compatibility with polymer. The XRD and FTIR results showed that physical and chemical interaction between the HNTs and polymer resin influenced the structure of UF owing to the functional groups on the HNTs. It is found from SEM images that the modified HNTs could be dispersed uniformly in the resin and the nanocomposite particles were spherical. The performance experiment confirmed that thermal stability of nanocomposite increased largely, formaldehyde emission of UF wood adhesive reduced 62%, and water resistance of UF wood adhesive improved by 84%. Meanwhile, the content of HNTs on the nanocomposites could be up to 60 wt %. The mechanism of the nanocomposites based on the reactive HNTs was proposed. The approach of the preparation could supply an idea to prepare other polymer/clay nanocomposites.

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Cross-population analysis for functional characterization of type II diabetes variants

BMC Bioinformatics ◽

10.1186/s12859-019-2835-0 ◽

2019 ◽

Vol 20 (S12) ◽

Cited By ~ 1

Author(s):

Dalia Elmansy ◽

Mehmet Koyutürk

Keyword(s):

Type Ii Diabetes ◽

Population Analysis ◽

Functional Characterization ◽

Type Ii

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Structure and sequence of the chicken type II procollagen gene. Characterization of the region encoding the carboxyl-terminal telopeptide and propeptide.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(17)42868-7 ◽

1984 ◽

Vol 259 (12) ◽

pp. 7826-7834 ◽

Cited By ~ 11

Author(s):

L J Sandell ◽

H L Prentice ◽

D Kravis ◽

W B Upholt

Keyword(s):

Type Ii ◽

Gene Characterization ◽

Carboxyl Terminal

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Functional Characterization of Undenatured Type II Collagen Supplements: Are They Interchangeable?

Journal of Dietary Supplements ◽

10.1080/19390211.2021.1931621 ◽

2021 ◽

pp. 1-16

Author(s):

Robert B. Harris ◽

Fernando L. A Fonseca ◽

Matthew H. Sharp ◽

Charlie R. Ottinger

Keyword(s):

Functional Characterization ◽

Type Ii Collagen ◽

Type Ii ◽

Undenatured Type Ii Collagen

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Semi-Crystalline Hydrophobic Polyamidoamines: A New Family of Technological Materials?

Polymers ◽

10.3390/polym13071018 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1018

Author(s):

Massimo Marcioni ◽

Jenny Alongi ◽

Elisabetta Ranucci ◽

Mario Malinconico ◽

Paola Laurienzo ◽

...

Keyword(s):

Maximum Stress ◽

Water Resistance ◽

Prolonged Exposure ◽

Water Soluble ◽

Synthesis And Characterization ◽

Molecular Weights ◽

New Family ◽

Methylene Groups ◽

Methane Flame

The hitherto known polyamidoamines (PAAs) are not suitable as structural materials because they are usually water-soluble or swellable in water. This paper deals with the synthesis and characterization of semi-crystalline hydrophobic PAAs (H-PAAs) by combining different bis-sec-amines with bis-acrylamides obtained from C6–C12 bis-prim-amines. H-PAAs were initially obtained in a solution of benzyl alcohol, a solvent suitable for both monomers and polymers. Their number average molecular weights, M¯n, which were determined with 1H-NMR by evaluating the percentage of their terminal units, varied from 6000 to >10,000. The solubility, thermal properties, ignitability and water resistance of H-PAAs were determined. They were soluble in organic solvents, semi-crystalline and thermally stable. The most promising ones were also prepared using a bulk process, which has never been previously reported for PAA synthesis. In the form of films, these H-PAAs were apparently unaffected by water. The films underwent tensile and wettability tests. They showed similar Young moduli (260–263 MPa), whereas the maximum stress and the stress at break depended on the number of methylene groups of the starting bis-acrylamides. Their wettability was somewhat higher than that of common Nylons. Interestingly, none of the H-PAAs considered, either as films or powders, ignited after prolonged exposure to a methane flame.

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