scholarly journals Enhancement of Flame Retardancy and Mechanical Properties of Polylactic Acid with a Biodegradable Fire-Retardant Filler System Based on Bamboo Charcoal

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2167
Author(s):  
Wenzhu Li ◽  
Liang Zhang ◽  
Weisheng Chai ◽  
Ningning Yin ◽  
Kate Semple ◽  
...  
Keyword(s):  
Heat Release ◽  
Polylactic Acid ◽  
Flame Retardancy ◽  
Chemical Elements ◽  
Fire Retardant ◽  
Strength Properties ◽  
Bamboo Charcoal ◽  
Adhesion Promoter ◽  
Limiting Oxygen Index ◽  
Air Atmosphere

A cooperative flame-retardant system based on natural intumescent-grafted bamboo charcoal (BC) and chitosan (CS) was developed for polylactic acid (PLA) with improved flame retardancy and minimal decline in strength properties. Chitosan (CS) as an adhesion promoter improved the interfacial compatibility between graft-modified bamboo charcoal (BC-m) and PLA leading to enhanced tensile properties by 11.11% and 8.42%, respectively for tensile strength and modulus. At 3 wt.% CS and 30 wt.% BC-m, the crystallinity of the composite increased to 38.92%, or 43 times that of pure PLA (0.9%). CS promotes the reorganization of the internal crystal structure. Thermogravimetric analysis showed significantly improved material retention of PLA composites in nitrogen and air atmosphere. Residue rate for 5 wt.% CS and 30 wt.% BC-m was 29.42% which is 55.1% higher than the theoretical value of 18.97%. Flammability tests (limiting oxygen index-LOI and UL-94) indicated significantly improved flame retardancy and evidence of cooperation between CS and BC-m, with calculated cooperative effectiveness index(Ce) >1. From CONE tests, the peak heat release rate (pHRR) and total heat release (THR) were reduced by 26.9% and 30.5%, respectively, for 3% CS + 20% BC-m in PLA compared with adding 20% BC-m alone. Analysis of carbon residue morphology, chemical elements and structure suggest CS and BC-m form a more stable char containing pyrophosphate. This char provides heat insulation to inhibit complete polymer pyrolysis, resulting in improved flame retardancy of PLA composites. Optimal mix may be recommended at 20% BC-m + 3% CS to balance compatibility, composite strength properties and flame retardance.

scholarly journals Development of Biodegradable Flame-Retardant Bamboo Charcoal Composites, Part I: Thermal and Elemental Analyses

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2217 ◽  
Author(s):  
Shanshan Wang ◽  
Liang Zhang ◽  
Kate Semple ◽  
Min Zhang ◽  
Wenbiao Zhang ◽  
...  
Keyword(s):  
Heat Release ◽  
Flame Retardant ◽  
Residue Analysis ◽  
Fire Retardant ◽  
Protective Layer ◽  
Growth Index ◽  
Raw Material ◽  
Bamboo Charcoal ◽  
Limiting Oxygen Index ◽  
Plastic Composite

In this study, bamboo charcoal (BC) was used as a substitute filler for bamboo powder (BP) in a lignocellulose-plastic composite made from polylactic acid (PLA), with aluminum hypophosphite (AHP) added as a fire retardant. A set of BC/PLA/AHP composites were successfully prepared and tested for flame-retardancy properties. Objectives were to (a) assess compatibility and dispersibility of BC and AHP fillers in PLA matrix, and (b) improve flame-retardant properties of PLA composite. BC reduced flexural properties while co-addition of AHP enhanced bonding between PLA and BC, improving strength and ductility properties. Adding AHP drastically reduced the heat release rate and total heat release of the composites by 72.2% compared with pure PLA. The formation of carbonized surface layers in the BC/PLA/AHP composites effectively improved the fire performance index (FPI) and reduced the fire growth index (FGI). Flame-retardant performance was significantly improved with limiting oxygen index (LOI) of BC/PLA/AHP composite increased to 31 vol%, providing a V-0 rating in UL-94 vertical flame test. Adding AHP promoted earlier initial thermal degradation of the surface of BC/PLA/AHP composites with a carbon residue rate up to 40.3%, providing a protective layer of char. Further raw material and char residue analysis are presented in Part II of this series.

scholarly journals Enhancement of Flame Retardancy of Colorless and Transparent Semi-Alicyclic Polyimide Film from Hydrogenated-BPDA and 4,4′-oxydianiline via the Incorporation of Phosphazene Oligomer

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 90
Author(s):  
Xiao Wu ◽  
Ganglan Jiang ◽  
Yan Zhang ◽  
Lin Wu ◽  
Yanjiang Jia ◽  
...  
Keyword(s):  
Heat Release ◽  
Flame Retardancy ◽  
Oxygen Index ◽  
Composite Films ◽  
Optical Transmittance ◽  
Polyimide Film ◽  
Total Heat Release ◽  
Limiting Oxygen Index ◽  
Biphenyltetracarboxylic Dianhydride ◽  
Thermal Stability Of

Enhancement of flame retardancy of a colorless and transparent semi-alicyclic polyimide (PI) film was carried out by the incorporation of phosphazene (PPZ) flame retardant (FR). For this purpose, PI-1 matrix was first synthesized from hydrogenated 3,3′,4,4′-biphenyltetracarboxylic dianhydride (HBPDA) and 4,4′-oxydianiline (ODA). The soluble PI-1 resin was dissolved in N,N-dimethylacetamide (DMAc) to afford the PI-1 solution, which was then physically blended with PPZ FR with the loading amounts in the range of 0–25 wt.%. The PPZ FR exhibited good miscibility with the PI-1 matrix when its proportion was lower than 10 wt.% in the composite films. PI-3 composite film with the PPZ loading of 10 wt.% showed an optical transmittance of 75% at the wavelength of 450 nm with a thickness of 50 μm. More importantly, PI-3 exhibited a flame retardancy class of UL 94 VTM-0 and reduced total heat release (THR), heat release rate (HRR), smoke production rate (SPR), and rate of smoke release (RSR) values during combustion compared with the original PI-1 film. In addition, PI-3 film had a limiting oxygen index (LOI) of 30.9%, which is much higher than that of PI-1 matrix (LOI: 20.1%). Finally, incorporation of PPZ FR decreased the thermal stability of the PI films. The 10% weight loss temperature (T10%) and the glass transition temperature (Tg) of the PI-3 film were 411.6 °C and 227.4 °C, respectively, which were lower than those of the PI-1 matrix (T10%: 487.3 °C; Tg: 260.6 °C)

Flammability and thermal properties of cotton fabrics modified with a novel flame retardant containing triazine and phosphorus components

2016 ◽  
Vol 87 (11) ◽  
pp. 1367-1376 ◽  
Author(s):  
Chaohong Dong ◽  
Zhou Lu ◽  
Peng Wang ◽  
Ping Zhu ◽  
Xuechao Li ◽  
...  
Keyword(s):  
Heat Release ◽  
Flame Retardant ◽  
Cotton Fabric ◽  
Flame Retardancy ◽  
Decomposition Temperature ◽  
Cotton Fabrics ◽  
Cone Calorimetry ◽  
Limiting Oxygen Index ◽  
Untreated Cotton ◽  
Index Value

A novel formaldehyde-free flame retardant containing phosphorus and dichlorotriazine components (CTAP) for cotton fabrics was synthesized. As an active group, the dichlorotriazine could react with cotton fabric via covalent reaction. The addition of 20.7 wt% CTAP into the cotton fabric obtained a high limiting oxygen index value of 31.5%, which was 13.5% higher than the pure cotton fabric. The results of heat release rate, total heat release and effective heat combustion indicated that CTAP effectively imparted flame retardancy to cotton fabric by the cone calorimetry test. With respect to the untreated cotton fabrics, the treated cotton fabrics degraded at lower decomposition temperature and form a consistent and compact char layer, which could be observed by thermogravimetric analysis, Fourier transform infrared spectroscopy and scanning electron microscopy. Compared to the untreated cotton fabrics, CTAP performed an effective role in flame retardancy for treated cotton fabrics. Meanwhile, it stimulated the formation of char and promoted the thermal stability of treated cotton fabrics during combustion.

scholarly journals Flame-retardancy and smoke suppression characteristics of bamboo impregnated with silicate-intercalated calcium aluminum hydrotalcates

BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 1311-1324
Author(s):  
Yating Hua ◽  
Chungui Du ◽  
Huilong Yu ◽  
Ailian Hu ◽  
Rui Peng ◽  
...  
Keyword(s):  
Heat Release ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Flame Retardants ◽  
Mass Loss Rate ◽  
Fire Retardant ◽  
Smoke Suppression ◽  
Cone Calorimetry ◽  
Before And After ◽  
Carbon Monoxide Yield

Flame-retardant silicate-intercalated calcium aluminum hydrotalcites (CaAl-SiO3-LDHs) were synthesized to treat bamboo for retardancy, to overcome the bamboo’s flammability and reduce the production of toxic smoke during combustion. The microstructure, elemental composition, flame retardancy, and smoke suppression characteristics of the bamboo before and after the fire-retardant treatment with different pressure impregnation were studied using a scanning electron microscope (SEM), elemental analysis (EDX), and cone calorimetry. It was found that CaAl-SiO3-LDHs flame retardants can effectively fill and cover the cell wall surface and the cell cavity of bamboo without damaging the microstructure. As compared to the non-flame-retardant bamboo, the heat release rate (HRR) of the CaAl-SiO3-LDHs flame-retardant bamboo was significantly reduced, the total heat release (THR) decreased by 31.3%, the residue mass increased by 51.4%, the time to ignition (TTI) delay rate reached 77.8%, the mass loss rate (MLR) decreased, and the carbon formation improved. Additionally, as compared to the non-flame-retardant bamboo, the total smoke release (TSR) of the CaAl-SiO3-LDHs flame-retardant bamboo decreased by 38.9%, and the carbon monoxide yield (YCO) approached zero. Thus, the CaAl-SiO3-LDHs flame-retardant bamboo has excellent flame-retardancy and smoke suppression characteristics.

scholarly journals Intumescent-Grafted Bamboo Charcoal: A Natural Nontoxic Fire-Retardant Filler for Polylactic Acid (PLA) Composites

ACS Omega ◽  
2021 ◽  
Author(s):  
Liang Zhang ◽  
Weisheng Chai ◽  
Wenzhu Li ◽  
Kate Semple ◽  
Ningning Yin ◽  
...  
Keyword(s):  
Polylactic Acid ◽  
Fire Retardant ◽  
Bamboo Charcoal

Synthesis of a Flame Retardant and Hydrophobic Epoxy Resin with Multiple Elements Synergistic Effect for Tunnel Seepage Prevention Application

2020 ◽  
Vol 842 ◽  
pp. 314-325
Author(s):  
Bin Lin
Keyword(s):  
Flame Retardant ◽  
Epoxy Resin ◽  
Flame Retardancy ◽  
Oxygen Index ◽  
Fire Retardant ◽  
Practical Application ◽  
Water Contact ◽  
Limiting Oxygen Index ◽  
New Perspective ◽  
Grouting Materials

Epoxy resin (EP) mortar usually used to repair the cracking of concrete structure under damp environment, but EP is extremely flammable, thus it’s extremely imperative to design a novel multifunction EP grouting materials with flame retardancy and waterproofness for the practical application. Targeting ingenious decoration of EP grouting materials, multiple flame retardant elements (phosphorus, nitrogen and fluorine) are concurrently introduced into a fire retardant and the fire retardant defined as DDM-FNP. The obtained DDM-FNP/EP grouting composite possess high thermal stability, flame retardancy and hydrophobicity. The limiting oxygen index (LOI) value of DDM-FNP/EP composites has a significant improve, which is increased from 26.7 (EP-0) to 35.8 (EP-4). Composites with more than 10 wt% of DDM-FNP could pass UL-94 V-0 rating without dripping. Compared with EP-0, the PHRR and THR of EP-4 are decreased by 31.1% and 21.6%, respectively. In addition, due to the introduction of the F element, the water contact angle of EP composites is changed from 75.2° (hydrophilicity) to 98.6° (hydrophobicity) after the introduction of a certain amount of DDM-FNP flame retardant. Therefore, this work provide a new perspective to design a multifunction EP grouting composite and improve the value of practical application on seepage prevention of tunnel.

scholarly journals Synthesis of a phosphoramidate flame retardant and its flame retardancy on cotton fabrics

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 550-560
Author(s):  
Huaifang Wang ◽  
Yingli Cai ◽  
Zhiming Jiang ◽  
Shengnan Guo ◽  
Ping Zhu
Keyword(s):  
Heat Release ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Cotton Fabrics ◽  
Limiting Oxygen Index ◽  
Flammability Test ◽  
Peak Heat Release Rate ◽  
Structure Surface ◽  
Ft Ir ◽  
Butanetetracarboxylic Acid

AbstractA phosphoramidate flame retardant (dimethyl N,N-bis(2-hydroxyletheyl)phosphoramidate, DMBHP) was synthesized and applied to cotton fabrics for enhancing the flame retardancy. The structure of DMBHP was characterized by FT-IR and NMR. The flame retardancy and combustion behavior of the treated cotton fabrics were evaluated using the vertical flammability test (VFT), limiting oxygen index (LOI), and the cone calorimetric test. Moreover, to further analyze the flame retardant action of DMBHP in cotton fabrics, thermal degradability of the treated fabrics, as well as the chemical structure, surface morphology, and element contents of the char residue of the DMBHP-treated fabrics were also evaluated. The results show that, after treating with DMBHP, the cotton fabrics acquired a LOI value from 18.1 to 31.1 with the concentration increasing to 30% and self-extinguished in VFT tests when treated with up to 15% DMBHP. Besides, the total heat release and the peak heat release rate of DMBHP (30%)-treated fabric decreased obviously compared with the pure cotton along with more residue retained. TG, SEM, and EDS results of treated cotton fabric and the corresponding residue after burning showed that DMBHP has the capability of enhancing char formation. In addition, DMBHP will confer cotton fabrics a certain durability against washing with the help of 1,2,3,4-butanetetracarboxylic acid (BTCA) and citric acid (CA).

scholarly journals Mechanical, Thermal and Fire Retardant Characteristics of NR/PP/ATH Thermoplastic Vulcanizates

2018 ◽  
Vol 16 (10) ◽  
pp. 723-737
Author(s):  
Natinee LOPATTANANON ◽  
Alif WALONG ◽  
Azizon KAESAMAN ◽  
Tadamoto SAKAI
Keyword(s):  
Electron Microscopy ◽  
Flame Retardancy ◽  
Elastic Recovery ◽  
Mass Loss Rate ◽  
Crosslinking Agent ◽  
Fire Retardant ◽  
Limiting Oxygen Index ◽  
Thermoplastic Vulcanizates ◽  
Pp Blends ◽  
Alumina Trihydrate

Blends of natural rubber (NR) and polypropylene (PP) were melt-mixed with phenolic resin crosslinking agent to obtain thermoplastic vulcanizates (TPVs). The blend composition of NR and PP was at 60/40 %wt. Alumina trihydrate (ATH) was incorporated into the blends to improve the flame retardancy, and the effect of ATH incorporation at different levels (20 - 120 PHP, part per hundred polymers) on blend morphology, ATH dispersion, mechanical properties, thermal resistance and flame retardancy was investigated. Analyses by transmission electron microscopy (TEM) and energy dispersive X-ray-scanning electron microscopy (EDX-SEM) revealed the dispersed phase-like morphology of 60/40 NR/PP TPVs. The presence of ATH in the TPVs did not have much influence on morphology of 60/40 NR/PP blends. Increasing ATH content decreased the dispersion level of ATH, which caused a decrease of tensile strength and elongation at break. Furthermore, an addition of ATH into the NR/PP blends resulted in lower elastic recovery, but slight increase of hardness. It was also found that the ATH suppressed the intensity of mass loss rate of NR and PP, resulting slower thermo-oxidative decomposition process of the blend materials. Limiting oxygen index (LOI) and UL94-V rate were enhanced with more incorporated ATH content. According to the results present in this study, the addition level of ATH for development of flame retardant NR/PP blend-based TPVs with acceptable elastomeric properties was recommended at 100 PHP.

Synergistic Effect between Modified Graphene Oxide and Ammonium Polyphosphate on Combustion Performance, Thermal Stability and Mechanical Properties of Polylactic Acid

2021 ◽  
Vol 36 (4) ◽  
pp. 367-378
Author(s):  
X.-Y. Pang ◽  
Y.-F. Meng ◽  
Y.-P. Xin ◽  
R. Chang ◽  
J.-Z. Xu
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Graphene Oxide ◽  
Heat Release ◽  
Polylactic Acid ◽  
Network Structure ◽  
Ammonium Polyphosphate ◽  
Limiting Oxygen Index ◽  
Combustion Performance ◽  
Modified Graphene Oxide

Abstract To improve the thermal stability, ZF-GO (graphene oxide (GO) modified by zinc ferrite (ZF)) is prepared. In view of the anti-dripping function of ZF-GO and flame retardant effect of ammonium polyphosphate (APP), the influence of ZF-GO, APP, mixture of ZF-GO and APP on combustion performance, thermal stability and mechanical properties of polylactic acid (PLA) is investigated. Results show that the modification of GO by ZF significantly improves the residue of ZFGO by 34.7%. The char-forming capability and unique network structure of ZF-GO prevent the melt dripping of PLA. Although APP can increase the limiting oxygen index of PLA, there is still melt dripping. The combination of ZF-GO and APP improves the residual yield of 94PLA/3ZF-GO/3APP by 4.3 times relative to pure PLA, and the UL-94 level reaches V-0. The two additives show synergistic char-forming effect, and there is both physical carbonization and chemical carbonization. The incorporated fillers can decrease the total heat release (THR) of PLA composites. Specifically, the THR and peak value of heat release rate of 94PLA/3ZF-GO/3APP decrease by 21.2% and 53.9%, respectively. For the PLA/ZF-GO/APP system, plenty of residues and the anti-dripping network structure are key factors to get good flame retardancy. Addition of ZFGO and APP reduces the tensile strength, but the tensile elongation of the modified PLA composites is improved. 94PLA/ 3ZF-GO/3APP shows good integrated performance.

The synergistic flame retardancy of modified expandable graphite and metal hydroxides on HDPE/EVA composites

2020 ◽  
pp. 089270572092513
Author(s):  
Xincheng Guo ◽  
Nian Liu ◽  
Lingtong Li ◽  
Zhuyu Bai ◽  
Xiaolang Chen ◽  
...  
Keyword(s):  
Heat Release ◽  
Flame Retardancy ◽  
Synergistic Effects ◽  
Zinc Borate ◽  
Expandable Graphite ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Limiting Oxygen Index ◽  
Cone Calorimeter Test ◽  
Ul 94

In this article, the flammable behaviors and synergistic effects of modified expanded graphite (MEG) with zinc borate (ZB) on flame-retardant high-density polyethylene/ethylene vinyl acetate (HDPE/EVA) composites containing magnesium hydroxide (MH) and aluminum hydroxide (ATH) are investigated by the Underwriters Laboratories-94 (UL-94) test, limiting oxygen index (LOI), cone calorimeter test (CCT), thermal gravimetric analysis (TGA), Fourier transform infrared (FTIR), differential scanning calorimetry, and tensile tests. The LOI, UL-94, and CCT results show that the synergistic effect of MEG and ZB can improve the flame retardancy of the composites. With the addition of ZB and MEG, the LOI value increases, and the UL-94 reaches the V-0 rating. The heat release rate and total heat release decrease, respectively. The data obtained from the TGA indicate that the synergistic effects of ZB with MEG increase the decomposition temperature when 2 phr ZB and 8 phr MEG are added into the composites. The data from FTIR show that HMEG8 and HMEG10 composites produce phosphate at high temperatures, which promotes the formation of stable and compact charred layer. All the results show that ZB and MEG have positive synergistic effects on HDPE/EVA composites containing MH and ATH. However, ZB and MEG play a negative role in the tensile properties of the HDPE/EVA composites.

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