Article
Polymer Science
Weixing Xu, Xintao Wu, Bi Shi
Summary: By using Cr-CF from chrome shavings to modify MF resin, the toughness and impact strength of the resin can be improved, thus achieving effective recycling of chrome shavings.
Article
Polymer Science
Natalia V. Bornosuz, Irina Yu. Gorbunova, Viktoria V. Petrakova, Vyacheslav V. Shutov, Vyacheslav V. Kireev, Denis V. Onuchin, Igor S. Sirotin
Summary: The influence of epoxycyclophosphazene modifier on epoxy-amine curing was studied using DSC, showing that epoxyphosphazene binders with DDS provide more complete curing compared to L-20. The curing process was described using model fitting and the isoconversional approach, revealing a diffusion-controlled mechanism at the final stage.
Article
Chemistry, Multidisciplinary
Yu-xuan Xu, Xing-guo Zhao, Xiang Dong, Guang-long Dai
Summary: Silane agents were used to synthesize organic-modified nickel phyllosilicates (NiPS), which were then introduced into epoxy resin (EP) to form composites. The effects of these organic-modified NiPS on the curing behavior and flammability of epoxy composites were carefully investigated. The addition of NiPS resulted in a narrower curing temperature range and decreased activation energy, indicating a lowered energetic barrier. The presence of these organic-modified NiPS also enhanced the self-extinguishing ability and limited oxygen index of the composites, and a solid phase flame retardant mechanism was proposed.
Article
Engineering, Chemical
Jinming Liu, Jingbo Lv, Haibing Yang, Xuechun Liu, Kailun Wang, Weixing Gan
Summary: Melamine formaldehyde resin (MF) has limitations in industrial application due to its high cost, high content of free formaldehyde and susceptibility to cracking. Biomass modification of MF offers a solution to these problems. The synthesis of sucrose melamine-formaldehyde copolymer resin (SMF) using sucrose, melamine, and formaldehyde as raw materials under alkaline conditions was studied. The findings revealed that the sucrose content and curing agent had significant impacts on the thermal stability and curing behavior of SMF.
INTERNATIONAL JOURNAL OF ADHESION AND ADHESIVES
(2024)
Article
Thermodynamics
Shanfeng Xu, Hui Xiao, Yuzhu Chen, Jing Li, Ke Jiang, Xie He, Jialin Zhang, Yongze Jiang, Xingyan Huang, Jiulong Xie, Jinqiu Qi
Summary: In this study, tea powder was used as a filler to produce low-formaldehyde-emission tea-based melamine-modified urea-formaldehyde resin. The thermal stabilities and performance of the resulting resin were characterized. The addition of tea powder showed positive effects on improving the properties of the plywood.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2021)
Article
Chemistry, Analytical
Robert V. Chimenti, Alexandra M. Lehman-Chong, Alyssa M. Sepcic, Jamison D. Engelhardt, James T. Carriere, Kayla A. Bensley, Adam Markashevsky, Jianwei Tu, Joseph F. Stanzione III, Samuel E. Lofland
Summary: Characterizing the extent of cure kinetics in polymers is crucial for understanding their structure-property-processing relationships. This study demonstrates a novel and non-destructive method of measuring polymerization kinetics using low-frequency Raman spectroscopy. By analyzing the disorder band and its shoulder in the spectrum, both structural and chemical conversion kinetics can be obtained. The results show a relationship between the chemical and structural kinetics, which may be related to the material's softness.
Article
Thermodynamics
Jaewook Lee, Byung-Dae Park
Summary: This study investigates the thermal cure kinetics of cold-setting MUF resins with different melamine contents using differential scanning calorimetry. The results show that the activation energy of the resins decreases as the degree of conversion increases, regardless of melamine content. However, the activation energy, isoconversional activation energy, and peak temperature increase as the melamine content increases. The KAS and Vyazovkin methods are reliable in estimating the cure kinetics of these resins.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Thermodynamics
Ehsan Abbasi, Ali Jannesari
Summary: The isothermal curing kinetics of a series of trimellitimide-derived epoxy-imide resins were studied and compared to their non-isothermal results. The curing process did not complete even though the minimum isothermal curing temperature was higher than the highest glass transition temperature. The values of isothermal activation energy were consistent with non-isothermal ones in the early stages but dramatically increased in the diffusion control regime.
THERMOCHIMICA ACTA
(2023)
Review
Chemistry, Applied
Ali Dorieh, Mohammad Farajollah Pour, Sogand Ghafari Movahed, Antonio Pizzi, Peyman Pouresmaeel Selakjani, Mohammad Valizadeh Kiamahalleh, Hamid Hatefnia, Mohammad Hassan Shahavi, Roozbeh Aghaei
Summary: Nanomaterials play a crucial role in enhancing the performance of MFR adhesives, improving mechanical properties, thermal stability, fire retardancy, and reducing free formaldehyde emission. The use of nanotechnology in synthesizing MFR nanocomposites can significantly decrease environmental and health hazards.
PROGRESS IN ORGANIC COATINGS
(2022)
Article
Engineering, Chemical
Chun-Feng Li, Ze-Xiu Qin, Yu Liu, Ya-Dong Pan, Ming-Li Liu
Summary: The addition of dispersed nano-SiO2 in a melamine/formaldehyde mixture improved the physical properties of a melamine formaldehyde resin. The incorporation of 0.42% eSiO(2) reduced the glass transition temperature of the resin and had minimal impact on its thermal stability. The modified resin showed different Raman spectra compared to the reference material, indicating changes in the hydroxymethyl and methylene bonds. These findings suggest that the addition of dispersed nano-SiO2 can enhance the toughness and other properties of the MF resin.
INTERNATIONAL JOURNAL OF ADHESION AND ADHESIVES
(2022)
Article
Chemistry, Multidisciplinary
Shahab Moghari, Seyed Hassan Jafari, Mohsen Khodadadi Yazdi, Maryam Jouyandeh, Aleksander Hejna, Payam Zarrintaj, Mohammad Reza Saeb
Summary: Surface modification of halloysite nanotubes (HNTs) using 8-hydroxyquinolines and synthesized aniline oligomers resulted in enhanced densification of epoxy resin networks, with pentamer AO-HNTs showing superior cure performance. Kinetic models accurately predicted the cure footprint observed in DSC measurements, highlighting the autocatalytic reaction order in AO-HNTs/epoxy system.
Article
Chemistry, Applied
Doudou Ding, Fa Gao, Yidan Wu, Yu Li, Tao Li, Baozeng Ren
Summary: In today's energy-depleted era, efficiently converting and storing energy is a major challenge. Carbon, with its good tailorability, inexpensiveness, and versatility, is widely used in electrode materials. Melamine formaldehyde resin (MF) containing large amounts of nitrogen (N) and amino groups can serve as carbon and nitrogen sources to produce electrode materials with superior electrochemical performance. However, the carbonization of MF has a low residue rate and underdeveloped pore structure, requiring in-depth research to improve this phenomenon. This paper discusses the preparation of MF, carbonization methods, pore-forming methods, doping methods, and composites with metal or other carbon materials to achieve electrode materials with enhanced performance and longer lifespan.
JOURNAL OF POROUS MATERIALS
(2023)
Article
Engineering, Chemical
Lei Kang, Lanjie Shi, Qiao Zeng, Bokai Liao, Bin Wang, Xingpeng Guo
Summary: This paper reports a technique for handling oil pollution incidents by modifying lignocellulose fibers, which exhibit excellent superhydrophobic and degradation properties after modification. This method not only points out a new direction for the comprehensive utilization of lignocellulose fibers, but also proposes a promising pathway for the development of oil-water remediation technology.
SEPARATION AND PURIFICATION TECHNOLOGY
(2021)
Article
Thermodynamics
Neda Yavari, Mehdi Poorabdollah, Laleh Rajabi
Summary: The curing behavior of pure unsaturated polyester resin, resin containing graphene oxide, and resin containing silane agent-modified graphene oxide was studied. The activation energies of resin curing were significantly influenced by the functional groups on the surfaces of graphene oxide and modified graphene oxide, as well as the presence of radical traps and stabilization of cobalt complexes by added particles. Diffusion phenomenon was investigated in all three systems, showing attraction interactions between particles and alkyd resin chains affecting the diffusion region of the systems containing graphene oxide.
THERMOCHIMICA ACTA
(2022)
Article
Materials Science, Paper & Wood
Mirela Angelita Artner, Pedro Henrique Gonzalez de Cademartori, Francisco Avelino, Diego Lomonaco, Washington Luiz Esteves Magalhaes
Summary: The study investigated the use of methanediol-based cellulose microfibril suspensions to enhance urea-formaldehyde resins, which resulted in improved resin performance and reduced environmental impact.
Article
Engineering, Environmental
Muhammad Adly Rahandi Lubis, Sumit Manohar Yadav, Byung-Dae Park
Summary: This study aimed to develop eco-friendly wood adhesive by modifying oxidized starch with nanoclay, resulting in improved viscosities, faster curing times, and enhanced thermal stability and adhesion strength. The intercalation of nanoclay within the polymer molecules led to reduced formaldehyde emissions, making it an environmentally friendly option for plywood adhesive.
JOURNAL OF POLYMERS AND THE ENVIRONMENT
(2021)
Article
Polymer Science
Eko Setio Wibowo, Byung-Dae Park
Summary: The study found that urea-formaldehyde resins at a low molar ratio exhibit a crystalline lamellar structure, while those at a high molar ratio have a highly amorphous structure, showing different properties and surface characteristics.
Article
Materials Science, Paper & Wood
Eko Setio Wibowo, Byung-Dae Park
Summary: This study measured the surface adhesion between cellulose and urea-formaldehyde resin adhesives. The results showed that the adhesion between 1.6 UF resins and nanocellulose is stronger due to the dominance of van der Waals forces. The higher surface free energy of 1.6 UF resins also contributes to the stronger adhesion.
Article
Materials Science, Multidisciplinary
Eko Setio Wibowo, Byung-Dae Park
Summary: The unique phenomenon of crystalline domain formation in thermosetting crystalline urea-formaldehyde (UF) resins at low formaldehyde-to-urea (F/U) molar ratios is responsible for their poor adhesion as wood adhesives. Through two-dimensional nuclear magnetic resonance (2D NMR) spectroscopy, clear evidence of the formation of linear molecules and subsequent hydrogen bonds in UF resins at low molar ratios has been reported for the first time. One-dimensional and 2D NMR spectroscopies were used for analyzing the short-range and long-range correlations between hydrogen, carbon, and nitrogen atoms in UF resin polymers prepared with different F/U molar ratios.
ACS APPLIED POLYMER MATERIALS
(2022)
Article
Forestry
Eko Setio Wibowo, Byung-Dae Park
Summary: This study investigated the effect of hemicellulose molecular structure on the wettability and surface adhesion properties of urea-formaldehyde resin adhesives. It was found that arabinogalactan hemicellulose had a hyperbranched structure, while xylan hemicellulose was more linear. As a result, their films exhibited different morphologies and surface characteristics. The adhesion between arabinogalactan and UF resins was stronger than that between xylan and UF resins, due to the former's higher surface free energy, more exposed OH groups, and smoother surface. Moreover, UF resins with a formaldehyde to urea molar ratio of 1.6 showed greater adhesion compared to those with a ratio of 1.0, regardless of the hemicellulose type, indicating that dispersion forces played a dominant role in their molecular interactions.
WOOD SCIENCE AND TECHNOLOGY
(2022)
Article
Chemistry, Applied
Hossein Khanjanzadeh, Byung-Dae Park, Hamidreza Pirayesh
Summary: In this study, colorimetric indicator films (CIFs) were developed by integrating immobilized neutral red and poly(acrylic acid) in a poly(vinyl alcohol) matrix. The CIFs showed visible color changes at different pH values and could be used for freshness detection in food packaging.
CARBOHYDRATE POLYMERS
(2022)
Article
Forestry
Minjeong Kim, Byung-Dae Park
Summary: The molecular weight of urea-formaldehyde (UF) resins affects the wettability and adhesion at wood surfaces. Higher molecular weight resulted in increased surface tension for 1.0 UF resins, while decreased surface tension for 1.6 UF resins. The contact angle of UF resins on wood surfaces was dependent on surface roughness, not resin molecular weight. Interphase adhesion was influenced by both resin molecular weight and wood type. However, the tensile shear strength of plywood did not directly correlate with the other factors.
WOOD SCIENCE AND TECHNOLOGY
(2022)
Article
Food Science & Technology
Hamidreza Pirayesh, Byung-Dae Park, Hossein Khanjanzadeh, Hye-Jin Park, Young-Je Cho
Summary: This study aims to develop green sustainable TEMPO-oxidized cellulose nanofibril (TOCNF)-based smart hydrogels triggered with different crosslinkers and anthocyanins (ACNs) from different sources for monitoring pork freshness. The cheap and environmentally friendly CFIs developed in this study could detect the pork warning stage and the medium fresh stages both qualitatively and quantitatively. The non-linear response of the CFIs to ammonia could indicate their potential to differentiate TVB-N mixtures contributing to the meat spoilage process.
Article
Thermodynamics
Jaewook Lee, Byung-Dae Park
Summary: This study investigates the thermal cure kinetics of cold-setting MUF resins with different melamine contents using differential scanning calorimetry. The results show that the activation energy of the resins decreases as the degree of conversion increases, regardless of melamine content. However, the activation energy, isoconversional activation energy, and peak temperature increase as the melamine content increases. The KAS and Vyazovkin methods are reliable in estimating the cure kinetics of these resins.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Thermodynamics
Seongsu Park, Long Yang, Byung-Dae Park, Guanben Du
Summary: In this study, the thermal cure kinetics of highly branched polyurea (HBPU) resins were investigated using differential scanning calorimetry. The results showed that the thermal curing of HBPU resins changed from chemical-controlled reaction to diffusion-controlled reaction as the molar ratio increased. The Malek method revealed that all HBPU resins followed an autocatalytic reaction model, regardless of the molar ratios. FWO and KAS methods were appropriate for predicting the reaction model of 2.0 and 3.0 HBPU resins when combined with the Malek method.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Biochemistry & Molecular Biology
Eko Setio Wibowo, Byung-Dae Park
Summary: Lignosulfonate, with sulfonate groups, is water-soluble and suitable for various applications. The study investigated the chemical and thermal characteristics of ion-exchanged sodium lignosulfonate (Na-LS) and compared it with industrial kraft lignin derived from softwood and hardwood. Results showed successful conversion of Na-LS to lignosulfonic acid (H-LS) through ion exchange, with H-LS having greater molecular weight and polymeric chains. H-LS also exhibited higher glass temperature (T-g) but faster degradation compared to Na-LS.
Article
Biochemistry & Molecular Biology
Yun Yeong Choi, Mi Jin Jang, Byung-Dae Park, In Chul Um
Summary: Five different nonwoven silk fabrics were fabricated using silk fibers from different cocoon layers to examine the effect of the cocoon layer on their structural characteristics and properties. The diameter of silk fiber and thickness of the nonwoven silk fabric decreased from the outer to inner cocoon layer. The properties of the nonwoven silk fabric, including crystallinity, contact angle, yellowness index, moisture retention, and mechanical properties, varied depending on the cocoon layer.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Engineering, Chemical
Ega Cyntia Watumlawar, Byung-Dae Park
Summary: This study focused on the fractionation of hardwood kraft lignin (HKL) using acetone and the synthesis of lignin-based adhesives through crosslinking with epichlorohydrin (ECH). The results showed that high molecular weight HKL has the potential as an adhesive for wood bonding.
JOURNAL OF ADHESION SCIENCE AND TECHNOLOGY
(2023)
Article
Polymer Science
Hye Gyeoung Lee, Mi Jin Jang, Byung-Dae Park, In Chul Um
Summary: Silk sericin, with good biocompatibility and high water retention, has attracted the attention of researchers as a promising biomaterial. However, its poor storage stability has limited its extensive use in biorelated applications. This study extracted and dried sericin from silkworm cocoon, and then dissolved it in hot water to improve its storage stability.
Article
Materials Science, Multidisciplinary
Eko Setio Wibowo, Byung-Dae Park
Summary: The unique phenomenon of crystalline domain formation in thermosetting crystalline urea-formaldehyde (UF) resins at low formaldehyde-to-urea (F/U) molar ratios is responsible for their poor adhesion as wood adhesives. Clear evidence for the formation of linear molecules and subsequent hydrogen bonds in the UF resins using two-dimensional nuclear magnetic resonance (2D NMR) spectroscopy is reported for the first time through our study.
ACS APPLIED POLYMER MATERIALS
(2022)
