Anti-dripping flame retardancy and mechanical properties of polylactide/ammonium polyphosphate/rayon fiber composites

Polylactide (PLA) composites containing a flame retadant, ammonium polyphosphate (APP), and short rayon fiber were prepared by direct melting compounding in a brabender. The limiting oxygen index (LOI) of the neat PLA sample was only 20.5%, which was increased to 29% by adding 15 wt% APP and 15% rayon to the PLA matrix (sample A15R15) as an example. During the UL-94 vertical flammability test, flame dripping was further avoided by adding the rayon fiber, and a V-0 rating was achieved. The char residue determined by thermogravimetric analysis (TGA) increased with increasing APP content in the PLA composites. However, the PLA composite revealed a loss in mechanical tensile modulus and strength due to the APP addition, which was improved when rayon fiber was added to replace a portion of APP.

Hydrophobic and Flame-Retardant Foam Based on Cellulose

A series of lightweight, hydrophobic, and fire retardant foams were fabricated through activation of cellulose by phosphoric acid as a primarily step. Dolomite clay was embedded onto the cellulosic suspensions with gelatin/ tannin as adhesive followed by freeze drying process. A solution of the environmentally friendly silicone rubber (RTV) was applied onto foam samples via spray-coating to improve their water repealing performance, which was explored by investigating both of water contacting angle and wettability time of the coated foam samples. Flammability characteristics, thermal decomposition, surface morphology, and chemical structure of treated and untreated foams were investigated by flammability test, thermogravimetric analysis, scanning electron microscopy, X-ray diffraction, and Fourier-transform infrared, respectively. Results showed that the foams loaded dolomite and coated RTV have high hydrophobicity as well as anti-inflammability.

Green Synthesis of Biobased P-N Coating Via Mechanochemistry Strategy: For High-Eficiency Flame Retardant Finish of Cotton Fabric

Cotton fabric is widely used in many occasions, but it is flammable with high fire risk. To meet the great fire safety demands of cotton fabric, a novel lignocellulosic-based P-N synergistic (LFPN) flame-retardant coating with high efficiency and environment friendly was developed via mechanochemistry strategy in the aqueous phase. The characterisation results showed the stable P-O-C bond formed to bind both lignocellulosic fibre and ammonium polyphosphate (APP). Meanwhile, LFPN has an excellent dispersion in water with a nanometer-scale enveloping rod structure. The cotton fabric treated by the LFPN coating showed outstanding flame-retardant properties, the peak heat release rate (PHRR) was reduced by 77% and the residue mass was increased by 259% compared with control cotton fabric. And there was a self-extinction phenomenon during the flammability test of flame retardant cotton. Based on the analysis of the combustion and pyrolysis process, a gas-condensed two-phase flame retardant mechanism model was proposed, which could be used to explain the action process of LFPN for cotton fabric during combustion.

Flexural and flammability evaluation of a new bio-based polyurethane foam with alumina trihydrate

Flexural and flammability evaluation of a new bio-based polyurethane foam (PUF) with alumina trihydrate (ATH) added as flame retardant were carried out. The PUF was obtained from a blend of vegetable oils. Flexural behavior of the polyurethane with different mass fractions of flame retardant (ATH) was investigated according to ASTM D790-17. Flammability tests were performed according to ASTM D3801-20 and ASTM D635-14 for the vertical and horizontal positions, respectively. The ATH addition influenced the flexural strength of the tested specimens, showing mean values for pure PUF and PUF with 50% of ATH were very close, but the highest value was obtained for PUF with 20% of ATH. Besides, the maximum strain value under flexural load was substantially reduced as the ATH mass increased, which was 11.4% for pure PUF and 3.38% for PUF with 50% of ATH. The flexural modulus increased with ATH incorporation up to 40% mass fraction. The obtained values for pure PUF, PUF with 40% of ATH and PUF with 50% of ATH specimens were 30.63 ± 1.95 MPa, 73.01 ± 2.82 MPa, and 62.16 ± 2.30 MPa, respectively. In addition, flammability test results presented better responses as the amount of ATH increased. PUF with 40% of ATH received V-2 classification, and PUF with 50% of ATH obtained HB classification. Therefore, the results for PUF with the addition of ATH show that the new bio-based material can be designed by using different mass fractions. Thus, this material becomes very useful for many types of applications, such as furniture and automobile industries, as well as sandwich structures and building constructions.

Extraction of Ethanol from Nypa fruticans (Nipa) Palm Fruit

Northern Samar is abundant when it comes to nipa resource which has a big potential as a raw material for ethanol. Utilization of nipa in Northern Samar is not optimal due to low interest and ability to process into useful products. The main aim of the study is to extract ethanol from nipa fruit to control the shortage of ethyl alcohol in the province. Fermentation was carried out after collection, washing, and cutting of nipa fruit through mixing 15 g of baker’s yeast to convert the sugar into alcohol for 12 days. Then, the distillation process followed to remove the excess water from the alcohol. Lastly, purification was done by adding lime (Calcium oxide) into the distillate in order to obtain ethanol. Result showed that the presence of ethanol was not observed after the 24 hours of fermentation since nipa fruit takes longer time to yield concentrated ethanol. But after 72 hours after fermentation it showed positive result from Iodoform test, Ester test, Litmus test, and Flammability test. It was concluded that nipa palm fruit could be a viable source of ethanol as compared to other plant-producing ethanol.

Flammability Tests and Investigations of Properties of Lignin-Containing Polymer Composites Based on Acrylates

In this paper flammability tests and detailed investigations of lignin-containing polymer composites’ properties are presented. Composites were obtained using bisphenol A glycerolate (1 glycerol/phenol) diacrylate (BPA.GDA), ethylene glycol dimethacrylate (EGDMA), and kraft lignin (lignin alkali, L) during UV curing. In order to evaluate the influence of lignin modification and the addition of flame retardant compounds on the thermal resistance of the obtained biocomposites, flammability tests have been conducted. After the modification with phosphoric acid (V) lignin, as well as diethyl vinylphosphonate, were used as flame retardant additives. The changes in the chemical structures (ATR-FTIR), as well as the influence of the different additives on the hardness, thermal (TG) and mechanical properties were discussed in detail. The samples after the flammability test were also studied to assess their thermal destruction.

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

A 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).

Fire Characteristics of Upholstery Materials in Seats

The article deals with selected upholstery flammability test materials that, in the case of fire, can cause fire spread. For the research, frequently used materials for upholstery based on polyester were utilized: imitation leather, suede, and microplush. Initiation of initiating spontaneous flammability with various sources of ignition were measured including a smoldering cigarette and a match flame. Results were measured as smoldering time and length of the burnt-though sample. Upholstery materials are an integral part of seat construction. To be used in transport, upholstered material must meet safety measures such as the strength, sanitariness, and fire resistance. All tests were performed in accordance with applicable technical standards. Impact assessment of the sample (weight) on “smoldering time” and “length of degradation” was carried out using an ANOVA. Significant differences in length of degradation was observed between samples. Tests cannot provide reliable information about the flammability course of the final product. Upholstery is composed of external covering, of inner liner, and padding. Results of the research presented in this paper indicate the need to continue the research in a broader aspect.

Expendable Graphite as an Efficient Flame-Retardant for Novel Partial Bio-Based Rigid Polyurethane Foams

The rigid polyurethane foam (PU) is a versatile material, used especially for construction and household applications. The current situation demands a facile, cost-efficient, and greener approach for developing the polyurethanes from bio-derived materials. In this study, we present a novel bio-polyol synthesized using carvone, an extract from caraway, spearmint, or dill seeds via facile thiol-ene reaction. Our one-step reaction uses a UV irradiation to allow the room temperature conversion of the carvone to a high purity bio-polyol, as confirmed from the standard analytical characterizations. The hydroxyl number of 365 mg KOH/g close to its theoretical limit confirms the high conversion yield of the polyol for rigid PU synthesis. To overcome the flammability issues in PU, expandable graphite (EG) powder was used as an additive flame-retardant during the synthesis step. The resulting foams with EG maintained the uniform closed cell structure (>95%) with a high compression strength of 175 kPa. The addition of EG in PU results in the formation of a protective char layer during the flammability test and reduces the weight loss from 40.70% to 3.55% and burning time from 87 to 11 s. Our results confirm that the carvone-based polyol can be a novel alternative to the petroleum polyols for an industrial-scale application.