Article
Polymer Science
Stephen M. Budy, Anderson Wey, Angelina Wu, David Y. Son
Summary: A new highly aromatic hardener, phenylated phenylenediamine (PDA), was synthesized and studied for its reaction process and properties with different epoxies. Thermal analysis and dynamic mechanical analysis were used to determine its thermal stability and thermal mechanical properties.
JOURNAL OF APPLIED POLYMER SCIENCE
(2022)
Article
Chemistry, Physical
Xue Wang, Anna -Christina Amason, Rebecca T. Miceli, Peng He, Yabin Lei, Ron Gabbard, Julie Ann Wieland, Robert J. Linhardt, David T. Corr, Richard A. Gross
Summary: By using safe biobased molecules to construct capsule walls, the health risks associated with synthetic chemicals can be reduced. The choice of DGEDP ester groups and amine hardeners significantly affects the microencapsulation efficiency and stability of the capsules.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2022)
Article
Polymer Science
Seok Jin Lim, Dae Su Kim
Summary: Partially epoxidized soybean oil (pESO) and fully epoxidized soybean oil (fESO) were used to modify a diglycidyl ether of bisphenol A (DGEBA) resin system in this study. The impact strength of the bio-epoxy resin system with fESO increased with ESO content, while the system with pESO showed higher tensile strength and elongation at break at ESO 30 wt%. The performance of the DGEBA/ESO bio-epoxy resin system could be tailored by changing ESO content and functionality.
JOURNAL OF APPLIED POLYMER SCIENCE
(2021)
Article
Green & Sustainable Science & Technology
Romain Tavernier, Mona Semsarilar, Sylvain Caillol
Summary: Since the 1940s, BPA has been widely used in the plastic industry, with a significant portion being utilized in the production of epoxy resins. However, extensive research has shown that BPA has endocrine-disrupting properties, necessitating the search for safer alternatives. This review provides a comprehensive analysis of bio-sourced aromatic substitutes for BPA, including their synthetic routes, toxicity, and impact on mechanical properties when used in the synthesis of epoxy resins.
Article
Chemistry, Multidisciplinary
Jie Xu, Nicolas Brodu, Boulos Youssef, Bechara Taouk
Summary: The synthesis of a greener novolac-type resin using glyoxal, upgraded bio-oil, and oxalic acid has been studied. The research demonstrated the potential of treated bio-oil products to effectively replace commercial phenol in the production of resin. The addition of biochar was found to improve the curing process by decreasing the onset temperature and activation energy.
Article
Environmental Sciences
Anila Bello, Yalong Xue, Dhimiter Bello
Summary: Occupational exposure to BADGE-based epoxy resins was studied among construction painters in this research, showing higher concentrations of biomarkers in mid-coat applicators' urine samples. It suggests the need for improvements in hygiene practices and personal protective measures during the application of epoxy-containing paintings.
ENVIRONMENT INTERNATIONAL
(2021)
Article
Food Science & Technology
Runhui Yang, Xianggui Chen, Yumin Niu, Bing Shao
Summary: Research has shown that Bisphenol A diglycidyl ethers (BADGE) undergoes biotransformation in vitro and in vivo, forming multiple metabolites. The metabolic transformation of BADGE can differ between species and gender, and some metabolites may have higher potential toxicity than BADGE itself.
FOOD AND CHEMICAL TOXICOLOGY
(2022)
Article
Agricultural Engineering
Dong-Mei Xie, Xiao-Li Zhao, Yi-Dong Li, Yunxuan Weng, Jian-Bing Zeng
Summary: This study successfully synthesized castor oil-based dynamic polymer networks with good mechanical properties, reprocessability, and recyclability. The networks also showed excellent solvent resistance, thermal stability, and durability. This provides important guidance for the synthesis of vegetable oil derived polymer networks that integrate tunable mechanical properties, reprocessability, and recyclability.
INDUSTRIAL CROPS AND PRODUCTS
(2022)
Article
Polymer Science
Katalin Czifrak, Csilla Lakatos, Gabriella Szabo, Bence Vadkerti, Lajos Daroczi, Miklos Zsuga, Sandor Keki
Summary: This study reported the preparation and systematic investigation of cross-linked polyurethane-epoxy (PU-EP) polymer systems. The PU-EP polymers were synthesized by reacting NCO-terminated PU prepolymers with diglycidyl ether of bisphenol A (DGEBA)-amine cooligomers. The addition of furfurylamine (FA) or ethanolamine (EA) resulted in the oligomerization of DGEBA and the formation of DGEBA-amine cooligomers. The cross-linking was achieved by adding the DGEBA-amine cooligomer to the PU prepolymers, forming urethane bonds as netpoints. The presence of furfurylamine allowed for the formation of additional thermoreversible bonds, leading to shape memory behavior in the PU-EP networks.
Article
Polymer Science
Juliana A. S. Montenegro, Andreas Ries, Ingridy D. S. Silva, Carlos B. B. Luna, Antonia L. Souza, Renate M. R. Wellen
Summary: In this study, both synthetic and enzymatic routes were investigated for the epoxidation of castor oil to reduce environmental impact. Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance in hydrogen molecules (H-1-NMR) were used to analyze the reactions. The results showed that the enzymatic reactions (6 h) and synthetic reactions achieved conversion rates of 50-96% and epoxidation rates of 25-48%. It was also observed that the absence of a solid catalyst resulted in a selectivity of 2% and the presence of solid catalysts (Amberlite and lipase enzyme) was crucial for the conversion of castor oil into oxirane rings.
Article
Chemistry, Multidisciplinary
Saeid Nikafshar, Jiarun Wang, Kevin Dunne, Prakit Sangthonganotai, Mojgan Nejad
Summary: Thirteen unmodified lignin samples from various biomass sources were used to replace bisphenol A (BPA) in epoxy resin formulations using a novel method. It was found that lignins with higher phenolic hydroxy content and lower molecular weights were more suitable for this purpose, and a regression model was developed to establish correlations between lignin properties and epoxy contents. Additionally, epoxidized lignin samples with high epoxy contents showed comparable performance to a petroleum-based epoxy system when cured with a bio-based hardener.
Article
Polymer Science
Istebreq A. Saeedi, Nikola Chalashkanov, Leonard A. Dissado, Alun S. Vaughan, Thomas Andritsch
Summary: In this study, a gamma relaxation in a series of epoxy resins based on DGEBA is measured and analyzed. By altering the network architecture and studying the temperature dependence of the loss peak frequency, a new interpretation of the relaxation process is proposed. It is found that the relaxation process can be best described as a thermally assisted tunnelling displacement of a proton. The proposed approach provides a new method for understanding gamma relaxations in these materials.
Article
Forestry
Hangchuan Cai, Zhiqi Wang, Di Xie, Panpan Zhao, Jianping Sun, Daoyu Qin, Fangchao Cheng
Summary: Transparent wood was prepared by alkaline pretreatment, bleaching treatment, and impregnation of epoxy resin, resulting in a flexible material with high transparency and outstanding mechanical properties. The research found that the delignification degree and the ratio of epoxy resin addition significantly influenced the optical and mechanical properties of the flexible transparent wood, with an optimal sample achieving high transmittance, ultra-high haze value, excellent flexibility, and mechanical strength. This study broadens the potential applications of transparent wood in flexible wearable devices and materials.
JOURNAL OF FORESTRY RESEARCH
(2021)
Article
Polymer Science
Michelle Souza Oliveira, Artur Camposo Pereira, Henry Alonso Colorado, Natalin Michele Meliande, Juliana dos Santos Carneiro da Cunha, Andre Ben-Hur da Silva Figueiredo, Sergio Neves Monteiro
Summary: The thermal and colorimetric parameters of DGEBA/TETA system (plain epoxy) and fique-fiber woven fabric-reinforced epoxy composites after thermal aging were investigated. The fique-fiber composites exhibited greater thermal stability but higher sensitivity to temperature variations compared to the plain epoxy.
Article
Polymer Science
Jose Vinicius Melo Barreto, Ananda Karoline Camelo de Albuquerque, Nicholas Guimaraes Jacques, Renate Maria Ramos Wellen
Summary: This study investigated the curing and degradation behavior of compounds made with bisphenol A diglycidyl ether and epoxidized soybean oil, cured with itaconic acid and succinic acid. The curing process followed the SN2 reaction mechanism and showed different activation energies for the two compounds. In terms of thermal degradation, four steps were observed, with EP/SUC exhibiting the lowest activation energy. The degradation mechanisms in both compounds were controlled by nucleation and subsequent growth.
JOURNAL OF APPLIED POLYMER SCIENCE
(2023)
