Xianling Fu^#, Hongliang Ding^#, Xin Wang^*, Lei Song, Yuan Hu^*

Journal of Renewable Materials, Vol.10, No.9, pp. 2303-2317, 2022, DOI:10.32604/jrm.2022.020759 - 30 May 2022

Abstract Although epoxy resin has been widely used in various fields, it still suffers from some problems including brittleness and flammability. In this study, a new phosphonic acid, N, N-bis(phosphomethyl) glycine (GDMP), was prepared by Mannich reaction with bio-based glycine and then a novel layered zirconium phosphonate (ZrGDMP) was synthesized using GDMP and zirconyl chloride hydrate as reactants. The chemical structure of ZrGDMP was well characterized by ¹H and ³¹P NMR, SEM, XRD and XPS. The effect of ZrGDMP on the flame retardancy, smoke suppression, strengthening and toughening performances of the epoxy matrix was investigated and evaluated.… More > Graphic Abstract

Haizhu Wu^1,#, Jinxing Li^1,#, Shouhu Bao¹, Fuxian Yang¹, Jun Zhang¹, Hisham Essawy^2,*, Guanben Du¹, Xiaojian Zhou^1,*

Journal of Renewable Materials, Vol.10, No.8, pp. 2029-2039, 2022, DOI:10.32604/jrm.2022.019834 - 25 April 2022

Abstract A cellular material in the form of 3-layered sandwich structure material was prepared via sole use of mechanical stirring without any use of a foaming agent, while Tween-80 was employed as a foam stabilizer via a developed in-situ mold casting. The resulting structure displayed a good appearance with no visual defects. The 3-layered composition of the sandwish structure, “nonporous resin layer-porous foam layer-nonporous resin layer”, was examined in terms of the microstructure, density & density distribution, pulverization ratio, mechanical strength, insulation and flame retardant performance. It was indicated from the results that the bonding between the… More > Graphic Abstract

Lara Greiner^1,*, Philipp Kukla², Sebastian Eibl¹, Manfred Döring³

Journal of Renewable Materials, Vol.10, No.7, pp. 1931-1950, 2022, DOI:10.32604/jrm.2022.019548 - 07 March 2022

Abstract A novel, versatile flame retardant substructure based on phosphorylated salicylic acid (SCP) is described and used in the synthesis of new flame retardants for HexFlow^® RTM6, a high-performance epoxy resin used in resin transfer molding processes as composite matrix. The starting material salicylic acid can be obtained from natural sources. SCP as reactive phosphorus chloride is converted with a novolak, a novolak containing 9, 10-dihydro-9- oxa-10-phospha-phenanthrene-10-oxide (DOPO) substituents or DOPO-hydroquinone to flame retardants with sufficient thermal stability and high char yield. Additionally, these flame retardants are soluble in the resin as well as react into the… More >

Hongxiang Liu^1,2,,*, Neng Xiong^1,2, Songli Wang^1,2, Wei Zhang^1,2, Bo Yong^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.3, pp. 549-561, 2022, DOI:10.32604/fdmp.2022.017979 - 22 February 2022

Abstract

The effects of a magnesium-based layered composite on the flammability of a phenolic epoxy resin (EP) are studied. In order to produce the required composite material, first, magnesium hydroxide, aluminum salt and deionized water are mixed into a reactor according to a certain proportion to induce a hydrothermal reaction; then, the feed liquid is filtered out using a solid-liquid separation procedure; finally, the material is dried and crushed. In order to evaluate its effects on the flammability of the EP, first, m-phenylenediamine is added to EP and vacuum defoamation is performed; then, EP is poured into

… More >

Li Wang^1,2,#, Rongbai Tong^3,#, Juanli Wang^1,2,*, Jintao Wan^1,2,*, Yuhu Li^1,2, Pujun Jin^1,2, Daodao Hu^1,2

Journal of Renewable Materials, Vol.10, No.5, pp. 1349-1364, 2022, DOI:10.32604/jrm.2022.019372 - 22 December 2021

Abstract Quest for bio-based halogen-free green flame retardant has attracted many concerns in recent years. Herein a reactive functional flame retardant containing phosphorus VDP is synthesized from vanillin, 9,10-dihydro-9-oxa-10-phosphophene-10-oxide (DOPO) and phenol via a facile way. VDP is characterized with ¹H NMR, ³¹P NMR, FTIR and Time of Flight Mass Spectrometry, and used as a new reactive flame retardant for bisphenol epoxy thermosets. Thermogravimetry analysis shows that when the VDP loading is only 0.5P% (based on phosphorus content), the residue increases from 14.2% to 21.1% at 750°C in N₂ compare with neat DGEBA. Correspondingly, the limit oxygen index… More >

Hongliang Ding, Xin Wang^*, Lei Song, Yuan Hu

Journal of Renewable Materials, Vol.10, No.4, pp. 871-895, 2022, DOI:10.32604/jrm.2022.018150 - 02 November 2021

Abstract Benzoxazines have attracted wide attention from academics all over the world because of their unique properties. However, most of the production and preparation of benzoxazine resins depends on petroleum resources now, especially bisphenol A-based benzoxazine. Therefore, owing to the environmental impacts, the development of bio-based benzoxazines is gaining more and more interest to substitute petroleum-based benzoxazines. Similar to petroleum-based benzoxazines, most of bio-based benzoxazines suffer from flammability. Thus, it is necessary to endow bio-based benzoxazines with outstanding flame retardancy. The purpose of this review is to summarize the latest advance in flame retardant bio-based benzoxazines. More > Graphic Abstract

Xue Xin^1,#, Yu Rong^1,#, Linping Su¹, Zhengmei Qiu¹, Chenjun Yang¹, Ming Liang^1,*, Ping Ji², Guoqiang Zhong³, Zhanyong Yao^1,*

Journal of Renewable Materials, Vol.10, No.4, pp. 1081-1095, 2022, DOI:10.32604/jrm.2022.018021 - 02 November 2021

Abstract As the important matrix material, epoxy resin has been widely used in the composites for various fields. On account of the poor toughness of epoxy resin limiting their suitability for advanced applications, considerable interests have been conducted to modify the epoxy resin to meet the engineering requirements. In this study, the bio-based polyurethane (PU) modified resin was adopted to modify the pure bisphenol-A epoxy by blending method with various proportions. Aiming to illuminate the curing behavior, mechanical and thermal properties, the blended epoxy systems were characterized by viscosity-time analysis, dynamic mechanical analysis (DMA) at different… More >

Hamed Younesi-Kordkheili^1,*, Antonio Pizzi²

Journal of Renewable Materials, Vol.10, No.2, pp. 237-246, 2022, DOI:10.32604/jrm.2022.017851 - 30 August 2021

Abstract The aim of this research was to investigate the effect of ionic liquid treated lignin-based polyacid as a catalyst for urea-formaldehyde (UF) resins. Esterification of lignin was carried out, without any catalyst, with anhydride maleic and 1-butyl-3-methylimidazolium hydrogen sulfate [Bmim][HSO₄] as acidic ionic liquid to form maleated lignin-based polyacids (MA-IL). The performance of MA-IL as UF resin catalyst was respectively compared to hyroxymethylated lignin-based polyacid (MA-HL) and to NH₄Cl. The FTIR analysis indicated that the proportion of -COOH and C-O bonds increased due to the esterification of lignin with ionic liquid rather than its hyroxymethylation. Physicochemical… More >

JITENDRA. S. TATE^1,2,*, HARISH KALLAGUNTA^1,2, ANDREW ALVAREZ¹

Journal of Polymer Materials, Vol.38, No.1-2, pp. 101-120, 2021, DOI:10.32381/JPM.2021.38.1-2.9

Abstract The exponential growth in composites and their increased use in military, aerospace, energy, and automotive industry is driven by their high performance and light weight. High performance thermosetting polymers such as cyanate ester have received considerable attention due to its ability of volatile-free curing. It also offers advantages such as excellent radiation shielding, high thermal stability, and hydrophobicity with lots of potential for enhanced mechanical strength. This research article discusses the results of effects of multiwalled carbon nanotubes (MWCNT) at predetermined loading levels of 0.5wt%, 1wt% and 1.5wt% on mechanical, thermal and flammability properties of More >

JALPA V. CHOPDA, DHARMESH B. SANKHAVARA, JIGNESH P. PATEL, P. H. PARSANIA^*

Journal of Polymer Materials, Vol.38, No.1-2, pp. 35-48, 2021, DOI:10.32381/JPM.2021.38.1-2.4

Abstract Conventional curing study of epoxy resin of (2E, 6E)-bis (4-hydroxybenzylidene)-4-methyl cyclohexanone (EMBHBC) was conducted at 140 0 /150 0 C by using 4,4’-diaminodiphenylmethane (DDM),4,4’-diaminodiphenylsulphone (DDS),4-4’-diaminodiphenyl ether (DDE), p-phenylenediamine (PDA), 1,2,3,6-tetrahydrophthalic anhydride(THPA), maleic anhydride (MAH) and pyromellitic dianhydride (PMDA). The gel time for DDS, THPA and DDM hardeners are found considerably longer than those of DDE, PDA, MAH and PMDA systems indicated different reactivity towards curing of EMBHBC. Sol–gel analysis of cured resins was carried out in DMF at room temperature. Diamines cured samples showed 76.3-97.5% gel fractions, while anhydrides cured samples showed 84.6-99.6% gel fractions.… More >