Chuanmei Jiao

Smoke suppression properties of carbon black on flame retardant thermoplastic polyurethane based on ammonium polyphosphate

Abstract In this paper, fumed silica has been used as smoke suppression and flame-retardant synergism in thermoplastic polyurethane (TPU) composites based on ammonium polyphosphate (APP). And, the synergistic smoke suppression property and flame-retardant effect of fumed silica in flame-retardant TPU composites are mainly intensively investigated by several methods, including smoke density test (SDT), cone calorimeter test (CCT), scanning electron microscopy (SEM), limiting oxygen index, and thermogravimetric analysis. The results of SDT show that fumed silica can significantly decrease smoke production of flame-retardant TPU composites. The results of CCT present that the addition of fumed silica can effectively reduce smoke production rate, total smoke release, smoke factor, heat release rate, and mass loss in the combustion process of flame-retardant TPU composites. The SEM results show that fumed silica can improve the quality of char residue after cone calorimeter test. All the results show that fumed silica is an effective smoke suppression agent and a good flame-retardant synergism with APP in TPU composites.

Flame Retardant Synergism of Hydroxy Silicone Oil and Al(OH)3 in EVA Composites

A synergistic effect on flame retardancy was found when hydroxy silicone oil (HSO) was incorporated into ethylene vinyl acetate/aluminum hydroxide (EVA/ATH) composite. The fire performance of EVA and EVA composites was studied by using limiting oxygen index (LOI), UL 94, and cone calorimeter test (CCT). Compared with the EVA/ATH binary composite, the LOI values of the EVA/ATH/HSO ternary composites at the same additive loading are all decreased. The CCT data indicated that the addition of HSO in EVA/ATH system not only reduces the heat release rate, but also prolonged the ignition time of the composite. Thermogravimetric analysis revealed that ATH accelerated the loss of acetic acid, but hydroxy silicone oil assisted to reduce ATHs accelerating effect.

Combustion behavior and thermal pyrolysis kinetics of flame-retardant epoxy composites based on organic–inorganic intumescent flame retardant

A novel organic–inorganic intumescent flame retardant, expandable graphite modified with charring agent (EGM), was synthesized using expandable graphite (EG), phosphorus oxychloride, and pentaerythritol. Then, EGM was used as flame retardant for epoxy resin. And the flame-retardant properties of epoxy composites were investigated by cone calorimeter test (CCT). The thermal degradation behaviors of epoxy composites were studied by thermogravimetric analysis (TG) in nitrogen atmosphere. And the pyrolysis kinetics of the composites was investigated using Kissinger and Flynn–Wall–Ozawa methods. The CCT result indicated that EGM can reduce the heat release rate and smoke production rate more than EG in flame-retardant epoxy composites: a more compact char residue formed on the surface of the sample with EGM than that of the sample with EG during the combustion process. The TG result showed that the sample with EGM has higher thermal stability than the sample with EG. And the data calculated from Kissinger and Flynn–Wall–Ozawa methods showed that both EP-0 and EP-3 had two thermal degradation stages; EGM can improve the Ea value of epoxy resins.

Synergistic effects between hollow glass microsphere and ammonium polyphosphate on flame-retardant thermoplastic polyurethane

It is mainly studied that the smoke-suppression properties and synergistic flame-retardant effect of hollow glass microsphere (HM) in flame retardant thermoplastic polyurethane (TPU) composites based on ammonium polyphosphate (APP) as a flame-retardant. Also, the smoke suppression properties and flame-retardant effect were investigated by smoke density test (SDT), cone calorimeter test (CCT), limiting oxygen index, and thermogravimetric analysis, separately. The char residues left after CCT were examined by scanning electron microscopy. The data of SDT shows that HM could effectively decrease smoke production of TPU composites. The results of CCT reveal that the system of APP/HM could reduce heat release rate, smoke production rate, and total smoke release. It is shown that APP/HM is a good system with smoke-suppression and synergistic flame-retardant properties in flame-retardant TPU composites.

Flame retardant epoxy resin based on bisphenol A epoxy resin modified by phosphoric acid

Flame retardant epoxy resin (FREP) were synthesized from phosphoric acid and bisphenol A epoxy resin (BAEP). The structure of the FREP was characterized using FTIR and 31P NMR. Then, several FREP/BAEP mass ratios were used to obtain materials with different phosphorus contents. The properties of the thermosetting materials were evaluated by limiting oxygen index, UL 94, cone calorimeter test, and thermogravimetric analysis. The results showed that the heat release rates and smoke production rates decreased greatly, and char residue increased with the increasing of FREP. It indicates that good flame retardant properties are related to the formation of a protective phosphorus-rich char layer.

Synergistic Effects of Fe2O3 with Layered Double Hydroxides in EVA/LDH Composites

The synergistic effects of Fe2O3 with layered double hydroxides (LDH) in ethylene vinyl acetate copolymer/LDH (EVA/LDH) composites have been studied using limiting oxygen index (LOI), UL-94 tests, and cone calorimeter test (CCT). The results from the LOI and UL-94 tests show that the Fe2O3 can also act as flame retardant synergistic agents in the EVA/LDH composites. The CCT data indicated that the addition of Fe2O3 in the EVA/LDH system can greatly reduce the heat release rate, total heat release, carbon monoxide and carbon dioxide.

Influence of iron oxide green on smoke suppression properties and combustion behavior of intumescent flame retardant epoxy composites

This article mainly studies smoke suppression properties and synergistic flame retardant effects of iron oxide green on intumescent flame retardant epoxy resins (IFREP) using ammonium polyphosphate and pentaerythritol as intumescent flame retardants. Then, the smoke suppression properties of iron oxide green (Fe2O3⋅H2O) on intumescent flame retardant epoxy composites were evaluated using cone calorimeter test (CCT), smoke density test (SDT), scanning electron microscopy (SEM), thermogravimetric analysis-infrared spectrometry. Remarkably, CCT data reveal that a moderate amount of iron oxide green can apparently reduce heat release rate, total heat release, total smoke release, etc. On the other hand, the SDT results show that iron oxide green can catalyze the carbonization of IFREP at low temperature. Here, iron oxide green is considered to be an effective smoke suppression agent and a good synergism with IFR in flame retardant epoxy resins, which can greatly improve the structure of char residue realized by SEM results.

Synergistic flame-retardant effects between aluminum hypophosphite and expandable graphite in silicone rubber composites

The main aim of this work was to investigate the synergistic effect of expandable graphite (EG) and aluminum hypophosphite (AHP) on the flame retardancy of silicone rubbers (SR). The synergistic effects of EG with AHP in halogen-free flame-retardant SR composites have been studied by cone calorimeter test (CCT), thermogravimetric analysis (TG), and the thermogravimetric analysis/infrared spectrometry (TG–IR). The CCT results showed that AHP and EG can effectively reduce the flammable properties including peak heat release rate, total heat release, smoke production rate, total smoke release, and smoke factor. An improvement of thermal stability of SR/AHP/EG was also observed. The experimental observations from digital photographs give positive evidence of the synergistic effects between AHP with EG. The TG results reveal that SR/AHP/EG samples show slower thermal degradation rate and higher thermal stability at high temperature than SR sample. The TG–IR results showed that the addition of AHP and EG significantly decreased the combustible gaseous products such as hydrocarbons. These attractive features of SR/AHP/EG suggest that the method proposed herein is a good approach to prepare very effective flame retardants and corresponding super flame-retarding SR.

A recycled environmental friendly flame retardant by modifying para-aramid fiber with phosphorus acid for thermoplastic polyurethane elastomer

The application of fibers is more and more extensive, and the pollution caused by abandoned fibers is getting more serious, which has aroused wide attention. So it is necessary to find a way to solve the problem. In this paper, the para-aramid fiber (AF) was recycled and modified by phosphoric acid, and then was applied as environmental friendly flame retardant for thermoplastic polyurethane elastomer (TPU). The flame retardant properties of TPU were tested using cone calorimeter test (CCT) and thermogravimetric/Fourier transform infrared spectroscopy (TG-IR). The CCT test showed that AF-P had better flame retardant effect on TPU than pure AF. Remarkably, the pHRR value for the sample with 1.00wt% content of AF-P was decreased by 48.1%; AF-P had improved the char forming progress and the residual mass was 30.6%, which was much more than pure TPU. TG test showed that AF-P could improve the thermal stability of TPU at high temperature. The TG-IR test revealed that AF-P had reduced the release of CO2 at the beginning. Based on the above results, it will make a great influence on the study of reuse of fibers and environmental friendly flame retardant of polymer.

Fire hazard reduction of hollow glass microspheres in thermoplastic polyurethane composites

Nowadays, reducing the fire hazard of thermoplastic polyurethane (TPU) is an important research direction in the fields of fire safety materials. In this article, hollow glass microsphere (HGM) was used to reduce the fire hazard of TPU in combustion process. The fire characteristics including smoke and heat production of TPU composites were evaluated using smoke density test (SDT) and cone calorimeter test (CCT). And the thermal decomposition and flammable properties were further studied using thermogravimetric analysis/infrared spectrometry (TG-IR) and limiting oxygen index (LOI), etc. The SDT results showed that the luminous flux (LF) of TPU4 containing 2.00wt% HGM was up to 24% at the end of test without flame, which is much higher than that of TPU0 (5%). And, the CCT results indicated that 2.00wt% HGM could make the total smoke release (TSR) decrease from 1019m2/m2 (TPU0) to 757m2/m2 (TPU4), reduced by 26%. The TG-IR results confirmed that HGM could improve the thermal stability of composites and reduce the production of some toxic gases. The above results illustrated HGM had a good prospect in reducing the fire hazard for TPU.