Special Issue "Bio-based Halogen-free Flame Retardant Polymeric Materials"

Submission Deadline: 30 September 2021 (closed)
Guest Editors
Xin Wang, Associate Professor, University of Science and Technology of China, China.
Dr. Xin Wang is an associate professor in the University of Science and Technology of China (USTC). He obtained his PhD in Safety Science and Engineering from the USTC in 2013. His research interests focus on synthesis of bio-based halogen-free flame retardants and preparation of novel nanomaterials, and their use in flame retardant polymeric composites. Up to now, he has been authored or co-authored more than 130 SCI-indexed papers in the peer-reviewed international journals (including 6 ESI highly-cited papers, total citations 6040, H index = 45), 5 book chapters and 1 monograph in this field.


The extensive utilization of polymeric materials in our daily life is driven by their superior comprehensive properties. However, polymeric materials are apt to be ignited with fast flame spread rate as well as the release of massive toxic gases and smoke during combustion. As a consequence, the relatively high fire hazards of polymeric materials account for a large number of property loss and casualties in polymer-related fire accidents every year worldwide. Thus, fire safety requirements on polymeric materials are currently attracting more and more attention in terms of difficulty of ignition, low heat release rate and low production of toxic gases and smoke. Over the past few decades, flame retardant technology from bio-based resources has gained increasing interests owing to increasing awareness on environmental protection and sustainable development. Bio-based halogen-free flame retardant is a hot research area nowadays as it is safe, non-toxic and sustainable flame retardant. This special issue mainly focuses on the latest advances in bio-based halogen-free flame retardant polymeric materials application. The scope of interests includes but is not limited to the following topics:


(1) Flame retardant additives derived from bio-based resources;

(2) Bio-based intrinsically flame retardant polymeric materials;

(3) Flame retardancy of bio-based or renewable polymer composites;

(4) Flame retardant polymer/natural fibers composites;

(5) Thermal degradation of bio-based or renewable polymer composites;

(6) Smoke suppression of bio-based or renewable polymer composites.

Bio-based resources; Polymeric materials; Flame retardant; Thermal degradation; Smoke suppression

Published Papers
  • Influence of Beta-Cyclodextrin Functionalized Tin Phenylphosphonate on the Thermal Stability and Flame Retardancy of Epoxy Composites
  • Abstract To enhance the thermal stability and flame retardancy of epoxy resin (EP), beta-cyclodextrin (β-CD) is successfully introduced into the layered tin phenylphosphonate (SnPP), which is incorporated into EP matrix for preparing EP/β-CD@SnPP composites. The results indicate that the addition of β-CD@SnPP obviously improve the thermal stability and residual yield of EP composites at higher temperature. When the amount of β-CD@SnPP is only 4 wt%, EP/4β-CD@SnPP composites pass V-1 rating, and LOI value is up to 30.8%. Meanwhile, β- CD@SnPP effectively suppress the heat release and reduce the smoke production of EP/β-CD@SnPP composites in combustion, and the peak heat release rate… More
  •   Views:1569       Downloads:542        Download PDF

  • Effect of MMT on Flame Retardancy of PLA/IFR/LDH Composites
  • Abstract Nano filler synergistic intumescent flame retardant (IFR) system is an effective way to improve the flame retardant properties of polymer. In this study, the effects of montmorillonite (MMT) on the flame retardant properties of polylactic acid/layered double hydroxides (PLA/LDH) and PLA/IFR/LDH were investigated. The results show that both LDH and LDH/IFR can reduce the peak heat release rate (HRR) of PLA and prolong the combustion time of PLA; When a proportionate MMT is introduced into PLA/LDH and PLA/IFR/LDH systems, respectively, MMT will not only affect the degradation process of PLA composites during combustion, but also the PLA composites can form… More
  •   Views:1354       Downloads:477        Download PDF

  • Phosphorylated Salicylic Acid as Flame Retardant in Epoxy Resins and Composites
  • 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 epoxy network. The determined… More
  •   Views:1067       Downloads:743        Download PDF

  • Halogen-Free Flame Retarded Poly(Lactic Acid) with an Isosorbide-Derived Polyphosphonate
  • Abstract Fabrication of flame retardants from renewable biomass has aroused extensive interest over the past decade. This work reported a synthesis of isosorbide-derived polyphosphonate (PICPP) as an anti-flammable agent for poly (lactic acid) (PLA). The presence of PICPP notably declined the storage modulus of PLA/PICPP owing to the declined molecular weight of PLA catalyzed by the presence of PICPP. PLA and PLA/PICPP thermally degraded in one stage under either air or nitrogen atmosphere. With increasing the amount of PICPP, the onset thermal decomposition temperature of PLA/PICPP was decreased gradually, owing to the earlier decomposition of PICPP. With only 10 wt% of… More
  •   Views:1147       Downloads:584        Download PDF

  • A New DOPO-Eugenol Adduct as an Effective Flame Retardant for Epoxy Thermosets with Improved Mechanical Properties
  • 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 with the onset thermal decomposition… More
  •   Views:1243       Downloads:756        Download PDF

  • A Vanillin-Derived, DOPO-Contained Bisphenol as a Reactive Flame Retardant for High-Performance Epoxy Thermosets
  • 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 increased to 29.6%,… More
  •   Views:1088       Downloads:1151        Download PDF

  • Bio-Based Trivalent Phytate: A Novel Strategy for Enhancing Fire Performance of Rigid Polyurethane Foam Composites
  • 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, which were the lowest, demonstrating… More
  • Graphical Abstract

    Bio-Based Trivalent Phytate: A Novel Strategy for Enhancing Fire Performance of Rigid Polyurethane Foam Composites
  •   Views:716       Downloads:593        Download PDF

  • Recent Advances in Flame Retardant Bio-Based Benzoxazine Resins
  • 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. First, three methods of the… More
  • Graphical Abstract

    Recent Advances in Flame Retardant Bio-Based Benzoxazine Resins
  •   Views:1298       Downloads:965       Cited by:1        Download PDF

  • Borate-Modified, Flame-Retardant Paper Packaging Materials for Archive Conservation
  • 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 break. Thermogravimetric analysis (TGA), scanning… More
  • Graphical Abstract

    Borate-Modified, Flame-Retardant Paper Packaging Materials for Archive Conservation
  •   Views:853       Downloads:597       Cited by:1        Download PDF

  • Study of Burning Behaviors and Fire Risk of Flame Retardant Plywood by Cone Calorimeter and TG Test
  • 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 plywood, while the average heat… More
  •   Views:1440       Downloads:850        Download PDF

  • Preparation and Properties of Bio-Based Flame Retardant L-APP/Poly(L-lactic acid) Composites
  • 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) and horizontalvertical burning tester. The… More
  • Graphical Abstract

    Preparation and Properties of Bio-Based Flame Retardant L-APP/Poly(L-lactic acid) Composites
  •   Views:1486       Downloads:844        Download PDF