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 >

Daqin Zhang^1,2, Chufeng Yang³, Huayang Ran^1,2, 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.7, pp. 1797-1811, 2022, DOI:10.32604/jrm.2022.018754 - 07 March 2022

Abstract The development of efficient green flame retardants is an important way to realize more sustainable epoxy thermosets and downstream materials. In this work, a monoepoxide is synthesized through O-glycidylation of eugenol, and then reacted with DOPO (9,10-dihydro-9-oxa-10-phosphophenanthrene-10-oxide) to obtain a new bio-based flame retardant, DOPO-GE. DOPO-GE is blended with a bisphenol A epoxy prepolymer exhibiting good compatibility and DDS (4,4′-diaminodiphenylsulfone) is used as the curing agent to afford epoxy thermosets. Although DOPO-GE leads to the reduced glass transition temperature of the thermosets, the storage modulus increases considerably. The DOPO-GE-modified thermosets exhibit the high thermal stability… 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 >

Bing Zhang¹, Sujie Yang¹, Mengru Liu¹, Panyue Wen², Xiuyu Liu¹, Gang Tang^1,*, Xiangrong Xu^3,4,*

Journal of Renewable Materials, Vol.10, No.5, pp. 1201-1220, 2022, DOI:10.32604/jrm.2022.018047 - 22 December 2021

Abstract Biomass phytic acid has potential flame retardant value as the main form of phosphorus in plant seeds. In this study, phytate-based flame retardants aluminum phytate (PA-Al) and iron phytate (PA-Fe) were synthesized and characterized. Subsequently, they were introduced into rigid polyurethane foam (RPUF) as flame retardants by one-step water-blown method. The results indicated that RPUF/PA-Fe30 exhibited the highest char residue of 22.1 wt%, significantly higher than 12.4 wt% of RPUF. Cone calorimetry analysis showed that the total heat release (THR) of RPUF/PA-Al30 decreased by 17.0% and total smoke release (TSR) decreased by 22.0% compared with pure RPUF, More > Graphic Abstract

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

Juanli Wang¹, Ming Cao², Jiaxin Li¹, Kaiyuan Li¹, Xiaolian Chao¹, Bingjie Mai¹, Yuhu Li^1,*, Jing Cao^1,*

Journal of Renewable Materials, Vol.10, No.4, pp. 1125-1136, 2022, DOI:10.32604/jrm.2022.018147 - 02 November 2021

Abstract Paper packaging materials like cardboards are widely used to protect archives which are a major kind of cultural relics. Unfortunately, paper is a combustible material, and thus exploring environment-friendly flame retardant for paper-based archive packaging material plays an important role. Herein, boric acid, borax and disodium octaborate are used to modify the craft paper-based packaging materials for archive conservation to improve fire safety. The modified craft paper exhibits much higher flame retardancy than the pristine one dose based on vertical burning tests, without much influence on mechanical properties such as tensile strength and elongation at More > Graphic Abstract

RAJKUMAR SINGH RAWAT^1,2, MEENU TALWAR^1,*, RAJENDRA KUMAR DIWAN², AJAY KUMAR TYAGI¹

Journal of Polymer Materials, Vol.38, No.3-4, pp. 281-294, 2021, DOI:10.32381/JPM.2021.38.3-4.9

Abstract In the present paper,boron based diluent was synthesized and incorporated in to a Ultraviolet (UV) radiation curable epoxy coating composition comprising of phosphorus based initiator (Trimethylbenzoyl diphenyl phosphine oxide) for enhancing its flame retardant property. The boron based diluent was synthesized by thermal polymerization technique. The presence of boron and phosphorus on the coating surface was confirmed by Energy Dispersive X-Ray (EDX) and X-ray photoelectron spectroscopy (XPS) techniques and functionality was determination by Fourier Transform Infra-Red (FTIR) and proton/boron NMR spectroscopy technique. The flame retardency property of the coating composition was confirmed by determining limiting More >

Liping Yu¹, Zhongyou Luo¹, Lifen Li¹, Xuedong Xi^2,3, Zhigang Wu^1,2,*, Bengang Zhang^4,*

Journal of Renewable Materials, Vol.9, No.12, pp. 2143-2157, 2021, DOI:10.32604/jrm.2021.016092 - 22 June 2021

Abstract A flame retardant composition was prepared by using phosphoguanidine, guanidine sulfamate, disodium octaborate tetrahydrate and dodecyl dimethyl benzyl ammonium chloride. Veneers were immersed in such flame retardant mixture to prepare plywood. The combustion characteristics and thermal stability of plywood were assessed using a cone calorimeter and TG. Results showed that: (1) High concentration and loading of flame retardant were beneficial for the fire resistance of the plywood. (2) The limiting oxygen index (LOI) and residual mass of plywood processed using the flame retardant was increased by 87.52% and 58.66% compared to those of the untreated… More >

Qionglin Luo¹, Mingliang Wang², Hui Zhang¹, Yuejun Ouyang¹, Hongwei Lin¹, You Shu^1,*, Shengpei Su^1,2,*

Journal of Renewable Materials, Vol.9, No.12, pp. 2067-2076, 2021, DOI:10.32604/jrm.2021.016255 - 22 June 2021

Abstract Poly(L-lactic acid) (PLLA) is a thermoplastic material with complete degradability, high biocompatibility and excellent mechanical properties. It can replace petroleum-based polymers are currently being used in the fields of packaging, agriculture, textiles, medical and so on. However, PLLA’s extremely flammability greatly limits its wider application. An bio-based flame retardant L-APP/PLLA composites was prepared by melt blending of the L-APP and PLLA. The morphology, impact properties, thermal properties and flame retardant properties of composites were investigated by field emission scanning electron microscope (SEM), impact tester, differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA), limiting oxygen indexer (LOI)… More > Graphic Abstract