US3962177 disclosed a series of mixtures of nickel and aluminum compounds to reduce poly(vinyl chloride) smoke formation. The investigated compositions obtained the V-0 class in the UL-94 flammability test. The international patent EP 2875069B1 described flame-retardant PVC compositions containing flame retardant agents, e.g., diantimony trioxide, zinc borate, and aluminum and calcium hypophosphites. The mentioned mixtures allow increases to the value of the oxygen index of poly(vinyl chloride) of up to 48%. US5886072 designated flame retardant compositions containing aluminum hydroxide, diantimony trioxide, brominated phthalic esters, isodecyl diphenyl phosphate, ammonium octamolybdate, and zinc borate for use in polyvinyl sheaths for electric cables. Among these additives, the solutions described below deserve particular attention. Ī way to reduce its flammability is through the introduction of fire retardant additives. PVC-P products primarily include boards and foils, cables, extruded profiles, artificial leather, floor coverings, and textiles. Additionally, it is impermeable to odors and oxygen, but degrades at elevated temperatures. PVC-P is characterized by high flexibility, transparency, and ease of processing, as well as resistance to weather conditions. Due to the presence of stabilizers, fillers, plasticizers, etc., there are two types of poly(vinyl chloride): unplasticized (PVC-U) and plasticized (PVC-P). Currently, European converters’ demand for poly(vinyl chloride) is over 6 million tons per year and is growing steadily, at an average of 5% per year, prompted by increasing investment in construction and infrastructure projects. Moreover, due to its high chlorine content (56.7%), PVC does not burn when the heat source or flame is removed. ĭue to its favorable properties, such as a high chemical and environmental resistance, ease of modification, widely developed processing methods, and low cost, poly(vinyl chloride) (PVC) is one of the most commonly used thermoplastics. Even though the dominant lethal factor is the presence of significant amounts of carbon dioxide, gases such as hydrogen cyanide, hydrogen chloride, hydrogen bromide, and hydrogen fluoride, also cause negative effects on the body, as well as causing confusion and loss of consciousness, which lead to death. Increases in the toxicity of gases is mainly related to the increase in the share of synthetic materials based on nitrogen and phosphorus, as well as substances containing significant amounts of halogen. These factors contribute to an increase in the intensity of heat release and faster flame spread, an increase in the amount of fumes emitted, and various chemical compounds being present in the fumes. The reasons for this change are creating open spaces with fewer barriers (e.g., doors, walls), the presence of larger number of flammable materials, and greater tightness of buildings. Research conducted by the US National Institute of Standards and Technology has shown that the time available for the evacuation of fire victims is only 3 min, while in the 1970s, it was 17 min. Based on a notable improvement, especially in smoke suppression suggests that the n/LHP system may be a candidate fire retardant for decreasing the flammability of PVC-P.Īlthough the number of fires in the United States decreased by 2.5% from 2009 to 2018, the number of fatalities increased significantly, by as much as 20.5%. The effects were compared to those achieved for PVC-P, PVC-P with a commercially available fire retardant, the substrate used for the produced LHP, and the mixture of LHP and zinc borate, both of which contained the same share of nanoclay. The research was complemented by a microstructure analysis, using a scanning electron microscope, of the materials before and after burning CC tests. In contrast, fire behavior and smoke emission were studied with a cone calorimeter (CC) and smoke density chamber. The thermal and thermodynamical properties of the PVC-P containing from 10 to 30 wt% of the fire retardant system (FRS) were determined by thermogravimetric analysis (TG) as well as by dynamic mechanical thermal analysis (DMTA). The current work assessed the burning behavior of plasticized poly(vinyl chloride) (PVC-P) modified with a two-component composition, consisting of L-histidinium dihydrogen phosphate-phosphoric acid (LHP) and nanoclay (n).
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