1
|
Hao Z, Xi X, Hou D, Lei H, Li C, Xu G, Du G. A fully bio-based soy protein wood adhesive modified by citric acid with high water tolerance. Int J Biol Macromol 2023; 253:127135. [PMID: 37802444 DOI: 10.1016/j.ijbiomac.2023.127135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 09/06/2023] [Accepted: 09/27/2023] [Indexed: 10/10/2023]
Abstract
Despite the widespread application prospect of soybean meal flour (SF) as a non-toxic and renewable wood adhesive, the practical application is limited by its poor mechanical properties and water resistance. In this work, a novel SF-based wood adhesive (CSP) was developed using citric acid (CA) as a modifier, which was further designated to produce plywood on a laboratory scale. Moreover, the effects of the mass ratio of CA/SF, hot-pressing temperature, and hot-pressing time on the bonding properties and water resistance of the resulting plywood were investigated in detail. As a result, under the optimal hot-pressing conditions (180 °C, 5 min), high-performance plywood bonded by CSP (CA/SF = 15/100) adhesive was fabricated, whose dry shear strength, cold-water wet shear strength (20 °C for 24 h), and hot-water wet shear strength (63 °C for 3 h) reached 1.65 MPa, 1.99 MPa, and 1.58 MPa, respectively. Due to the easy preparation process, sustainability, and favorable properties, the proposed fully bio-based CSP wood adhesive has great potential for the large-scale fabrication of eco-friendly wood panels in industry.
Collapse
Affiliation(s)
- Ziteng Hao
- Yunnan Key Laboratory of Wood Adhesives and Glued Products, College of Material and Chemical Engineering, Southwest Forestry University, Kunming 650224, China
| | - Xuedong Xi
- Yunnan Key Laboratory of Wood Adhesives and Glued Products, College of Material and Chemical Engineering, Southwest Forestry University, Kunming 650224, China
| | - Defa Hou
- Yunnan Key Laboratory of Wood Adhesives and Glued Products, College of Material and Chemical Engineering, Southwest Forestry University, Kunming 650224, China.
| | - Hong Lei
- College of Chemistry and Material Engineering, Zhejiang Agriculture and Forestry University, Hangzhou 311300, China.
| | - Chunyin Li
- Yunnan Key Laboratory of Wood Adhesives and Glued Products, College of Material and Chemical Engineering, Southwest Forestry University, Kunming 650224, China
| | - Gaoxiang Xu
- Yunnan Key Laboratory of Wood Adhesives and Glued Products, College of Material and Chemical Engineering, Southwest Forestry University, Kunming 650224, China
| | - Guanben Du
- Yunnan Key Laboratory of Wood Adhesives and Glued Products, College of Material and Chemical Engineering, Southwest Forestry University, Kunming 650224, China
| |
Collapse
|
2
|
Li M, Chen Y, Kong Z, Sun Z, Qian L. Impact of a Novel Phosphoramide Flame Retardant on the Fire Behavior and Transparency of Thermoplastic Polyurethane Elastomers. ACS OMEGA 2023; 8:18151-18164. [PMID: 37251156 PMCID: PMC10210028 DOI: 10.1021/acsomega.3c01464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Accepted: 04/25/2023] [Indexed: 05/31/2023]
Abstract
In many application fields of thermoplastic polyurethane (TPU), excellent flame retardancy and transparency are required. However, higher flame retardancy is often at the expense of transparency. It is difficult to achieve high flame retardancy while maintaining the transparency of TPU. In this work, a kind of TPU composite with good flame retardancy and light transmittance was obtained by adding a new synthetic flame retardant named DCPCD, which was synthesized by the reaction of diethylenetriamine and diphenyl phosphorochloridate. Experimental results showed that 6.0 wt % DCPCD endowed TPU with a limiting oxygen index value of 27.3%, passing the UL 94 V-0 rating in the vertical burning test. The cone calorimeter test results showed that the peak heat release rate (PHRR) of the TPU composite was dramatically reduced from 1292 kW/m2 (pure TPU) to 514 kW/m2 by adding only 1 wt % DCPCD. With the increase of DCPCD contents, the PHRR and total heat release gradually decreased, and the char residue gradually increased. More importantly, the addition of DCPCD has little effect on the transparency and haze of TPU composites. In addition, scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy were carried out to investigate the morphology and composition of the char residue for TPU/DCPCD composites and explore the flame retardant mechanism of DCPCD in TPU.
Collapse
Affiliation(s)
- Mengqi Li
- School
of Chemistry and Materials Engineering, Beijing Technology and Business University, Beijing 100048, China
- China
Light Industry Engineering Technology Research Center of Advanced
Flame Retardants, Beijing 100048, China
- Petroleum
and Chemical Industry Engineering Laboratory of Non-halogen Flame
Retardants for Polymers, Beijing 100048, China
| | - Yajun Chen
- School
of Chemistry and Materials Engineering, Beijing Technology and Business University, Beijing 100048, China
- China
Light Industry Engineering Technology Research Center of Advanced
Flame Retardants, Beijing 100048, China
- Petroleum
and Chemical Industry Engineering Laboratory of Non-halogen Flame
Retardants for Polymers, Beijing 100048, China
| | - Zimeng Kong
- School
of Chemistry and Materials Engineering, Beijing Technology and Business University, Beijing 100048, China
- China
Light Industry Engineering Technology Research Center of Advanced
Flame Retardants, Beijing 100048, China
- Petroleum
and Chemical Industry Engineering Laboratory of Non-halogen Flame
Retardants for Polymers, Beijing 100048, China
| | - Zhe Sun
- School
of Chemistry and Materials Engineering, Beijing Technology and Business University, Beijing 100048, China
- China
Light Industry Engineering Technology Research Center of Advanced
Flame Retardants, Beijing 100048, China
- Petroleum
and Chemical Industry Engineering Laboratory of Non-halogen Flame
Retardants for Polymers, Beijing 100048, China
| | - Lijun Qian
- School
of Chemistry and Materials Engineering, Beijing Technology and Business University, Beijing 100048, China
- China
Light Industry Engineering Technology Research Center of Advanced
Flame Retardants, Beijing 100048, China
- Petroleum
and Chemical Industry Engineering Laboratory of Non-halogen Flame
Retardants for Polymers, Beijing 100048, China
| |
Collapse
|
3
|
Zhang B, Wang J, Zhang F, Wu L, Guo B, Gao Z, Zhang L. Preparation of a High-Temperature Soybean Meal-Based Adhesive with Desired Properties via Recombination of Protein Molecules. ACS OMEGA 2022; 7:23138-23146. [PMID: 35847336 PMCID: PMC9280771 DOI: 10.1021/acsomega.2c00833] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
A soybean protein-based adhesive with desired adhesion properties and low processing cost is prepared by a simple and practical method, which is of great significance to the sustainable utilization of resources and human health. Nevertheless, the protein of high-temperature soybean meal (HSM) has a high degree of denaturation and low solubility, endowing the resultant soybean-based adhesive with a high viscosity and unstable bonding performance. Herein, we propose the strategy of protein molecular recombination to improve the bonding properties of the adhesive. First, chemical denaturation was carried out under the combined action of sodium sulfite, sodium dodecyl sulfate, sodium hydroxide, urea, or sodium dodecyl sulfate/sodium hydroxide to reshape the structure of the protein to release active groups. Then, thermal treatment was employed to facilitate the protein repolymerization and protein-carbohydrate Maillard reaction. Meanwhile, the epichlorohydrin-modified polyamide (PAE) as a crosslinking agent was introduced to recombine unfolded protein and the products from Maillard reaction to develop an eco-friendly soy protein-based adhesive with an excellent and stable bonding performance. As expected, the highest cycle wet bond strength of the adhesive sample of 1.20 MPa was attained by adding a combination of 2% SDS and 0.5% sodium hydroxide, exceeding the value required for structural use (0.98 MPa) of 22.44% according to the JIS K6806-2003 commercial standard. Moreover, the adhesive possessed the preferable viscosity and viscosity stability accompanied by good wettability. Noteworthily, the adhesive had a short time of dry glue, which could be solved by combining it with soybean meal (SM) at the ratio of 30:10.
Collapse
Affiliation(s)
- Binghan Zhang
- Department
of Chemistry and Chemical Engineering, Heze
University, Heze, Shandong 274015, China
| | - Jinguo Wang
- Heze
Forestry Administration, Heze, Shandong 274015, China
| | - Fengrong Zhang
- Department
of Chemistry and Chemical Engineering, Heze
University, Heze, Shandong 274015, China
| | - Lishun Wu
- Department
of Chemistry and Chemical Engineering, Heze
University, Heze, Shandong 274015, China
| | - Baicheng Guo
- Department
of Chemistry and Chemical Engineering, Heze
University, Heze, Shandong 274015, China
| | - Zhenhua Gao
- Key
Laboratory of Bio-Based Material Science and Technology (Ministry
of Education), Northeast Forestry University, Harbin 150040, China
| | - Leipeng Zhang
- Center
for Composite Materials and Structure, Harbin
Institute of Technology, Harbin 150001, China
| |
Collapse
|
4
|
Lamaming SZ, Lamaming J, Rawi NFM, Hashim R, Kassim MHM, Hussin MH, Bustami Y, Sulaiman O, Amini MHM, Hiziroglu S. Improvements and limitation of soy protein‐based adhesive: A review. POLYM ENG SCI 2021. [DOI: 10.1002/pen.25782] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Sofie Zarina Lamaming
- Division of Bioresource Technology, School of Industrial Technology Universiti Sains Malaysia Penang Malaysia
| | - Junidah Lamaming
- Chemical Engineering Program, Faculty of Engineering Universiti Malaysia Sabah Kota Kinabalu Sabah Malaysia
| | - Nurul Fazita Mohammad Rawi
- Division of Bioresource Technology, School of Industrial Technology Universiti Sains Malaysia Penang Malaysia
| | - Rokiah Hashim
- Division of Bioresource Technology, School of Industrial Technology Universiti Sains Malaysia Penang Malaysia
| | | | | | - Yazmin Bustami
- School of Biological Sciences Universiti Sains Malaysia Penang Malaysia
| | - Othman Sulaiman
- Division of Bioresource Technology, School of Industrial Technology Universiti Sains Malaysia Penang Malaysia
| | | | - Salim Hiziroglu
- Department of Natural Resource Ecology and Management Oklahoma State University Stillwater Oklahoma USA
| |
Collapse
|
5
|
Jiang K, Lei Z, Yi M, Lv W, Jing M, Feng Q, Tan H, Chen Y, Xiao H. Improved performance of soy protein adhesive with melamine-urea-formaldehyde prepolymer. RSC Adv 2021; 11:27126-27134. [PMID: 35480695 PMCID: PMC9037677 DOI: 10.1039/d1ra00850a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 08/03/2021] [Indexed: 11/21/2022] Open
Abstract
In recent years, soy protein adhesive, as an environmentally friendly bio-based adhesive, has attracted extensive attention. In this study, in order to ameliorate the bonding quality of soy protein isolate (SPI) adhesive, the melamine–urea–formaldehyde prepolymer (MUFP) was synthesized, and different amounts of it were introduced into the SPI adhesive as a cross-linking agent. Fourier transform infrared (FT-IR) spectroscopy, gel permeation chromatography (GPC), thermogravimetric analyze (TGA), and scanning electron microscopy (SEM) were used to analysis the mechanism of modification. The results of plywood test indicated that the wet bonding strength of the adhesives was first increased and then decreased with an increase in the amount of MUFP additive. FT-IR, TGA, and SEM tests suggested that the introduction of MUFP could promote the establishment of a cross-linking structure in the cured adhesive layer to improve the bonding quality of adhesives, but presence of excessive MUFP could introduce hydrophilic groups and adversely affect water resistance. In recent years, soy protein adhesive, as an environmentally friendly bio-based adhesive, has attracted extensive attention.![]()
Collapse
Affiliation(s)
- Ke Jiang
- College of Forestry, Sichuan Agricultural University Chengdu 611130 Sichuan China.,Key Laboratory of Wood Industry and Furniture Engineering, Sichuan Provincial Department of Education, Sichuan Agricultural University Chengdu 611130 Sichuan China +86-028-86291456
| | - Zhenghui Lei
- College of Forestry, Sichuan Agricultural University Chengdu 611130 Sichuan China.,Key Laboratory of Wood Industry and Furniture Engineering, Sichuan Provincial Department of Education, Sichuan Agricultural University Chengdu 611130 Sichuan China +86-028-86291456
| | - Maoyu Yi
- College of Forestry, Sichuan Agricultural University Chengdu 611130 Sichuan China.,Key Laboratory of Wood Industry and Furniture Engineering, Sichuan Provincial Department of Education, Sichuan Agricultural University Chengdu 611130 Sichuan China +86-028-86291456
| | - Wenxin Lv
- College of Forestry, Sichuan Agricultural University Chengdu 611130 Sichuan China.,Key Laboratory of Wood Industry and Furniture Engineering, Sichuan Provincial Department of Education, Sichuan Agricultural University Chengdu 611130 Sichuan China +86-028-86291456
| | - Mingwei Jing
- College of Forestry, Sichuan Agricultural University Chengdu 611130 Sichuan China.,Key Laboratory of Wood Industry and Furniture Engineering, Sichuan Provincial Department of Education, Sichuan Agricultural University Chengdu 611130 Sichuan China +86-028-86291456
| | - Qiaoling Feng
- College of Forestry, Sichuan Agricultural University Chengdu 611130 Sichuan China.,Key Laboratory of Wood Industry and Furniture Engineering, Sichuan Provincial Department of Education, Sichuan Agricultural University Chengdu 611130 Sichuan China +86-028-86291456
| | - Hailu Tan
- College of Forestry, Sichuan Agricultural University Chengdu 611130 Sichuan China.,Key Laboratory of Wood Industry and Furniture Engineering, Sichuan Provincial Department of Education, Sichuan Agricultural University Chengdu 611130 Sichuan China +86-028-86291456
| | - Yuzhu Chen
- College of Forestry, Sichuan Agricultural University Chengdu 611130 Sichuan China.,Key Laboratory of Wood Industry and Furniture Engineering, Sichuan Provincial Department of Education, Sichuan Agricultural University Chengdu 611130 Sichuan China +86-028-86291456
| | - Hui Xiao
- College of Forestry, Sichuan Agricultural University Chengdu 611130 Sichuan China.,Key Laboratory of Wood Industry and Furniture Engineering, Sichuan Provincial Department of Education, Sichuan Agricultural University Chengdu 611130 Sichuan China +86-028-86291456
| |
Collapse
|
6
|
Wang H, Wang L, Zhang S, Zhang W, Li J, Han Y. Mussel‐inspired polymer materials derived from nonphytogenic and phytogenic catechol derivatives and their applications. POLYM INT 2021. [DOI: 10.1002/pi.6230] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Hanzhang Wang
- Key Laboratory of Wood‐Based Materials Science and Utilization Beijing Forestry University Beijing China
- Beijing Key Laboratory of Wood Science and Engineering Beijing Forestry University Beijing China
| | - Liuliu Wang
- Key Laboratory of Wood‐Based Materials Science and Utilization Beijing Forestry University Beijing China
- Beijing Key Laboratory of Wood Science and Engineering Beijing Forestry University Beijing China
| | - Shifeng Zhang
- Key Laboratory of Wood‐Based Materials Science and Utilization Beijing Forestry University Beijing China
- Beijing Key Laboratory of Wood Science and Engineering Beijing Forestry University Beijing China
| | - Wei Zhang
- Key Laboratory of Wood‐Based Materials Science and Utilization Beijing Forestry University Beijing China
- Beijing Key Laboratory of Wood Science and Engineering Beijing Forestry University Beijing China
| | - Jianzhang Li
- Key Laboratory of Wood‐Based Materials Science and Utilization Beijing Forestry University Beijing China
- Beijing Key Laboratory of Wood Science and Engineering Beijing Forestry University Beijing China
| | - Yanming Han
- Research Institute of Forestry New Technology, Chinese Academy of Forestry Beijing China
| |
Collapse
|
7
|
Upadhyaya S, Konwar A, Chowdhury D, Sarma NS. High-performance water-borne fluorescent acrylic-based adhesive: synthesis and application. RSC Adv 2020; 10:25408-25417. [PMID: 35518622 PMCID: PMC9055326 DOI: 10.1039/d0ra03782f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 06/16/2020] [Indexed: 01/13/2023] Open
Abstract
Water-borne adhesives have immense importance in cellulose-based materials, where their durability, handling, and strength remain to be a major concern. The present work demonstrates the development of three water-borne adhesives, namely, poly(1-vinyl-2-pyrrolidone-co-acrylic acid), poly(acrylonitrile-co-acrylic acid), and poly(1-vinyl-2-pyrrolidone-co-acrylonitrile-co-acrylic acid) applicable for cellulose-based materials. These acrylic-acid based adhesives were characterized by Fourier-transform infra-red spectroscopy, thermogravimetric analysis, X-ray diffraction, gel permeation chromatography, and universal testing machine. The synthesized polymer adhesives can be stored in the powder form for a longer period, thus utilizing less space. In order to use as adhesives, suitable formulations can be prepared in water. The adhesives show thermal stability up to 300 °C. Our studies show that poly(1-vinyl-2-pyrrolidone-co-acrylonitrile-co-acrylic acid) showed higher lap shear strength (ASTM D-906) than commercially available adhesives. In addition, these adhesives, being fluorescent in nature, can be detected under UV light and thus are applicable for the detection of fractured joints of any specimen. This property also helps in anti-counterfeiting applications, thus adding further to their utility. Synthesis and application of a water-borne fluorescent acrylic adhesive, which can be stored as a powder for long-term use.![]()
Collapse
Affiliation(s)
- Samiran Upadhyaya
- Advanced Materials Laboratory, Institute of Advanced Study in Science and Technology Paschim Boragaon Guwahati-35 Assam India
| | - Achyut Konwar
- Materials Nanochemistry Laboratory, Institute of Advanced Study in Science and Technology Paschim Boragaon Guwahati-35 Assam India
| | - Devasish Chowdhury
- Materials Nanochemistry Laboratory, Institute of Advanced Study in Science and Technology Paschim Boragaon Guwahati-35 Assam India
| | - Neelotpal Sen Sarma
- Advanced Materials Laboratory, Institute of Advanced Study in Science and Technology Paschim Boragaon Guwahati-35 Assam India
| |
Collapse
|
8
|
An Eco-Effective Soybean Meal-Based Adhesive Enhanced with Diglycidyl Resorcinol Ether. Polymers (Basel) 2020; 12:polym12040954. [PMID: 32326006 PMCID: PMC7240682 DOI: 10.3390/polym12040954] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 04/13/2020] [Accepted: 04/15/2020] [Indexed: 01/01/2023] Open
Abstract
Soybean meal-based adhesive is a good wood adhesive mainly due to its renewable, degradable, and environmentally friendly features. To improve the enhancement efficiency for adhesives, diglycidyl resorcinol ether (DRE) containing a benzene ring and flexible chain structure was used as an efficient cross-linker to enhance the adhesive in the study. The physicochemical properties of adhesives, the dry shear strength, and wet shear strength of plywood were measured. Results suggested that DRE reacted with the functional groups of soybean meal adhesive and formed a cross-linking network during hot press process in a ring-opening reaction through a covalent bond. As expected, compared to adhesive control, the soybean meal adhesive with 4 wt% DRE incorporation showed a significant increment in wet shear strength by 227.8% and in dry shear strength by 82.7%. In short, soybean meal adhesive enhanced with DRE showed considerable potential as a wood adhesive for industrial applications.
Collapse
|
9
|
Effects of Different Denaturants on Properties and Performance of Soy Protein-Based Adhesive. Polymers (Basel) 2019; 11:polym11081262. [PMID: 31366098 PMCID: PMC6723224 DOI: 10.3390/polym11081262] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 07/10/2019] [Accepted: 07/24/2019] [Indexed: 02/06/2023] Open
Abstract
Chemical modification of soy protein, via crosslinking, is the preferred method for creating non-toxic, renewable, environmentally friendly wood adhesives. The denaturing process of protein is important for the adhesive performance improvement. In order to investigate the effect of different denaturing agents on the performance of soy protein-based adhesives before and after crosslinking modification. In this study, three different denaturing agents—urea (U), sodium dodecyl sulfate (SDS), and sodium hydrogen sulfite (SHS) and an epoxide crosslinking agent—Triglycidylamine (CA) were used to prepare soy protein-based adhesives. The results showed: (1) The denaturing agent unfolded protein molecules and exposed more hydrophobic groups to prevent water intrusion, which was mainly a contribution for the water resistance and performance improvement of soy protein-based adhesives. The wet shear strength was improved up to 91.3% (denaturing by urea). (2) After modifying by the crosslinking agent, the properties and performance improvement was due to the fact that the active groups on soybean protein molecules reacted with the crosslinking agent to form a crosslinking structure, and there is no obvious correlation with the hydrophobic groups of the protein. (3) The unfolded soybean protein molecules also expose hydrophilic groups, which facilitates the reaction between the crosslinking agent and protein to form a denser crosslinking structure to improve the performance of the adhesive. Particularly, after denaturing with SHS, the wet shear strength of the plywood bonded by the SPI-SHS-CA adhesive increased by 217.24%.
Collapse
|
10
|
Zhang J, Zhang Y, Li J, Gao Q. Development of a High-Performance Adhesive with a Microphase, Separation Crosslinking Structure Using Wheat Flour and a Hydroxymethyl Melamine Prepolymer. Polymers (Basel) 2019; 11:E893. [PMID: 31096681 PMCID: PMC6571881 DOI: 10.3390/polym11050893] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 05/11/2019] [Accepted: 05/13/2019] [Indexed: 12/15/2022] Open
Abstract
The objective of this study is to use wheat flour (WF) and hydroxymethyl melamine prepolymer (HMP) to develop a low cost, highly water-resistant, starch-based bio-adhesive for plywood fabrication. Three-layer plywood was fabricated using the resultant adhesive, and the wet shear strength of the plywood samples was measured under various conditions. After determining that water resistance was significantly improved with the addition of HMP, we evaluated the physical characteristics of the starch-based adhesive and functional groups and analyzed the thermal stability and fracture surface of the cured adhesive samples. Results showed that by adding 20 wt.% HMP into WF adhesive, the sedimentation volume in the resultant adhesive decreased by 11.3%, indicating that the increase of crosslinking in the structure of the adhesives increased the bond strength, and the wet shear strength of the resultant plywood in 63 °C water improved by 375% when compared with the WF adhesive. After increasing the addition of HMP to 40 wt.%, the wet shear strength of the resultant plywood in 100 °C water changed from 0 MPa to 0.71 MPa, which meets the exterior use plywood requirement. This water resistance and bond strength improvement resulted from (1) HMP reacting with functions in WF and forming a crosslinking structure to prevent moisture intrusion; and (2) HMP self-crosslinking and combining with crosslinked WF to form a microphase separation crosslinking structure, which improved both the crosslinking density and the toughness of the adhesive, and subsequently, the adhesive's bond performance. In addition, the microphase separation crosslinking structure had better thermostability and created a compact ductile fracture surface, which further improved the bond performance of the adhesive. Thus, using a prepolymer to form a microphase separation crosslinking structure within the adhesive improves the rigidity, toughness, and water resistance of the material in a practical and cost-effective manner.
Collapse
Affiliation(s)
- Jieyu Zhang
- Key Laboratory of Wood Material Science and Utilization, Beijing Forestry University, Beijing 100083, China.
- Ministry of Education, Beijing Key Laboratory of Wood Science and Engineering, College of Materials Science and Technology, Beijing Forestry University, Beijing 100083, China.
| | - Yi Zhang
- Key Laboratory of Wood Material Science and Utilization, Beijing Forestry University, Beijing 100083, China.
- Ministry of Education, Beijing Key Laboratory of Wood Science and Engineering, College of Materials Science and Technology, Beijing Forestry University, Beijing 100083, China.
| | - Jianzhang Li
- Key Laboratory of Wood Material Science and Utilization, Beijing Forestry University, Beijing 100083, China.
- Ministry of Education, Beijing Key Laboratory of Wood Science and Engineering, College of Materials Science and Technology, Beijing Forestry University, Beijing 100083, China.
| | - Qiang Gao
- Key Laboratory of Wood Material Science and Utilization, Beijing Forestry University, Beijing 100083, China.
- Ministry of Education, Beijing Key Laboratory of Wood Science and Engineering, College of Materials Science and Technology, Beijing Forestry University, Beijing 100083, China.
| |
Collapse
|