Thermal stability and flame retardancy of an epoxy resin modified with phosphoric triamide and glycidyl POSS

2019 ◽  
Vol 31 (9-10) ◽  
pp. 1217-1225 ◽  
Author(s):  
Jialiang Li ◽  
Hongyu Wang ◽  
Shichao Li

Phosphoric triamide (PTA) and glycidyl polyhedral oligomeric silsesquioxane (POSS) were simultaneously incorporated into the cured network of a bisphenol F epoxy resin and 4,4′-diaminodiphenyl methane (DDM) to improve the thermal stability and flame retardancy. PTA was synthesized by triethyl phosphate and DDM, and its chemical structure was confirmed by 1H nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR). The differential scanning calorimetric (DSC) results showed that the introduction of PTA and POSS slightly increased the glass transition temperature of the epoxy resin. The thermogravimetric analysis results indicated that compared with the pure, phosphoric, and silicic epoxy resins, the modified epoxy resin possessed the lowest weight loss rate and highest char residue. Its limiting oxygen index value was as high as 30.5, and the UL-94 grade reached V-1. A decomposition test was carried out to obtain sufficient char residue and investigate the condensed mechanism. The scanning electron microscopic images demonstrated that the char residue of the modified epoxy resin had a compact structure. The energy dispersive X-ray and FTIR analyses verified the synergistic effect of the phosphorus and silicon in the PTA and POSS, respectively, on the epoxy resin.

2012 ◽  
Vol 482-484 ◽  
pp. 1863-1868 ◽  
Author(s):  
Ya Wen Huang ◽  
Jia Jun Ma ◽  
Jun Xiao Yang

Copolymer of p-phenylenediamine and bispirocyclic pentaerythritol diphosphate was synthesized and characterized by FTIR and 1H NMR. This polymer was used to prepare epoxy resin/SPDA composites. Thermal stability of SPDA and epoxy/SPDA composites were investigated by thermogravimetric analysis (TGA), and their flammability were investigated by the LOI test. TGA results showed that the addition of SPDA improved the char residue of epoxy resin. SEM investigation showed that the residual chars have a honeycomb-like structure, indicating an intumescent flame retarding effect of SPDA in composites. In addition, all of above results confirmed that accelerate carbonization play a key role in improving flame retardancy of epoxy resin.


10.6036/10327 ◽  
2022 ◽  
Vol 97 (1) ◽  
pp. 98-103
Author(s):  
XIAN WANG ◽  
JINLONG ZHUO ◽  
TIANQING XING ◽  
Xingran Wang

In order to reduce flammability, smoke release and enhance thermal stability of epoxy resin (EP), iron powder is mixed with graphene oxide/ epoxy resin (GO/EP) composite by mechanical blending. The combustion performance of composite material is investigated through limiting oxygen index (LOI), Underwriters Laboratory (UL)-94 test, and cone calorimeter test (CCT). Thermogravimetric-Fourier transform infrared spectroscopy (TG-FTIR) and scanning electron microscope (SEM) are also used to explore the mechanism of flame retardancy and smoke suppression. Results show that, with the addition of 0.5% mass fraction of GO and the corresponding iron powder combination (EP3 sample), the LOI value can achieve 32.5% while reaching the UL-94 V0 rating. Compare with EP0, the peaks of heat release rate, smoke production rate, and smoke factor values of EP3 are decreased by 42%, 60%, and 50%, respectively. The char and TG-FTIR data of EP3 reveal that it has a more compact structure, good thermal stability, and produce fewer toxic gases and smoke. Reduction of GO could inhibit the degradation of EP, and iron catalyzes the formation of carbonaceous char on the surface. Thus, the thermal stability and flame retardancy of EP are improved significantly. This study provides a suitable way to prepare graphene/EP composites that contain iron catalyst and can be extended to the industrial manufacture of flame retardant polymer composites. Keywords: iron powder; epoxy resin; graphene oxide; flame retardant; thermal stability


2016 ◽  
Vol 29 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Xiaodong Jin ◽  
Chen Chen ◽  
Jun Sun ◽  
Xing Zhang ◽  
Xiaoyu Gu ◽  
...  

Expandable graphite (EG) has attracted more and more attention in fire science society due to its excellent char-forming ability, however, it cannot meet commercial flame-retardant requirements because of the low intensity of the char. This work reported our very recent efforts on improving the char quality of EG by introducing melamine (MEL) in order to enhance the fire resistance and thermal stability of polyamide 11 (PA 11) composite. The flammability characterized by limiting oxygen index, UL-94 vertical burning, and cone calorimeter (cone) tests shows that the presence of both EG and MEL can significantly improve the flame retardancy and thermal stability of PA 11 composites. The scanning electron microscopic analysis shows that EG and MEL are beneficial to form compact char layers that can isolate the matrix from heat and oxygen. It is proposed that the formation of hydrogen bonds between MEL and PA 11 are crucial for improving the flame retardancy of the composites.


Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3635
Author(s):  
Shaoling Lin ◽  
Boqing Tao ◽  
Xiaomin Zhao ◽  
Guohua Chen ◽  
De-Yi Wang

Recently, lots of effort has been placed into stabilizing black phosphorus (BP) in the air to improve its compatibility with polymers. Herein, BP was chemically functionalized by aliphatic amine (DETA), aromatic amine (PPDA) and cyclamine (Pid) via a nucleophilic substitution reaction, aiming to develop an intensively reactive BP flame retardant for epoxy resin (EP). The -NH2 group on BP-DETA, BP-PPDA and BP-Pid reacted with the epoxide group at different temperatures. The lowest temperature was about 150 °C for BP-DETA. The impacts of three BP-NH2 were compared on the flame retardancy and thermal decomposition of EP. At 5 wt% loading, EP/BP-NH2 all passed UL 94 V 0 rating. The limiting oxygen index (LOI) of EP/BP-PPDA was as high as 32.3%. The heat release rate (HRR) of EP/BP-DETA greatly decreased by 46% and char residue increased by 73.8%, whereas HRR of EP/BP-Pid decreased by 11.5% and char residue increased by 50.8%, compared with EP. Average effective heat of combustion (av-EHC) of EP/BP-Pid was lower than that of EP/BP-DETA and EP/BP-PPDA. In view of the flame-retardant mechanism, BP nanosheets functionalized with aliphatic amine and aromatic amine played a dominant role in the condensed phase, while BP functionalized with cyclamine was more effective in the gas phase.


2014 ◽  
Vol 1053 ◽  
pp. 263-267 ◽  
Author(s):  
Xiu Juan Tian

Thermal stability and thermal degradation kinetics of epoxy resins with 2-(Diphenylphosphinyl)-1, 4-benzenediol were investegated by thermogravimetric analysis (TGA) at different heating rates of 5 K/min, 10 K/min, 20 K/min and 40 K/min. The thermal degradation kinetic mechanism and models of the modified epoxy resins were determined by Coast Redfern method.The results showed that epoxy resins modified with the flame retardant had more thermal stability than pure epoxy resin. The solid-state decomposition mechanism of epoxy resin and the modified epoxy resin corresponded to the controlled decelerating ځ˽̈́˰̵̳͂͆ͅ˼˰̴̱̾˰̸̵̈́˰̵̸̳̱̹̽̾̓̽˰̶̳̹̾̈́̿̾̓ͅ˰̶˸ځ˹˰̵̵͇͂˰̃˸́˽ځ˹2/3. The introduction of phosphorus-containing flame retardant reduced thermal degradation rate of epoxy resins in the primary stage, and promote the formation of carbon layer.


1993 ◽  
Vol 11 (5) ◽  
pp. 442-456 ◽  
Author(s):  
Jun Zhang ◽  
Michael E. Hall ◽  
A. Richard Horrocks

This paper is the first in a series of four which investigates the burning behaviour and the influence of flame retardant species on the flam mability of fibre-forming polymer and copolymers of acrylonitrile. A pressed powdered polymer sheet technique is described that enables a range of polymer compositions in the presence and absence of flame retardants to be assessed for limiting oxygen index, burning rate and char residue deter minations. The method offers a rapid, reproducible and convenient means of screening possible flame retardant systems, and LOI values compare favourably with those of films and fabrics comprising the same polymeric type. Burning rates, however, are sensitive to changes in physical sample character such as form (film vs. powder sheet) and density. Thus the technique forms an excellent basis for the generation of burning data which will enable comprehensive studies of acrylic polymer flammability and flame retardancy to be undertaken.


2020 ◽  
Vol 15 ◽  
pp. 155892502090132
Author(s):  
Sang-Hoon Lee ◽  
Seung-Won Oh ◽  
Young-Hee Lee ◽  
Il-Jin Kim ◽  
Dong-Jin Lee ◽  
...  

To prepare flame-retardant epoxy resin, phosphorus compound containing di-hydroxyl group (10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phospha phenanthrene-10-oxide, DOPO-HQ) was reacted with uncured epoxy resin (diglycidyl ether of bisphenol A, YD-128) and then cured using a curing agent (dicyandiamide, DICY). This study focused on the effect of phosphorus compound/phosphorus content on physical properties and flame retardancy of cured epoxy resin. The thermal decomposition temperature of the cured epoxy resins (samples: P0, P1.5, P2.0, and P2.5, the number represents the wt% of phosphorus) increased with increasing the content of phosphorus compound/phosphorus (0/0, 19.8/1.5, 27.8/2.0, and 36.8/2.5 wt%) based on epoxy resin. The impact strength of the cured epoxy resin increased significantly with increasing phosphorus compound content. As the phosphorus compound/phosphorus content increased from 0/0 to 36.8/2.5 wt%, the glass transition temperature (the peak temperature of loss modulus curve) increased from 135.2°C to 142.0°C. In addition, as the content of phosphorous compound increased, the storage modulus remained almost constant up to higher temperature. The limiting oxygen index value of cured epoxy resin increased from 21.1% to 30.0% with increasing phosphorus compound/phosphorus content from 0/0 to 36.8/2.5 wt%. The UL 94 V test result showed that no rating for phosphorus compounds less than 19.8 wt% and V-1 for 27.8 wt%. However, when the phosphorus compound was 36.8 wt%, the V-0 level indicating complete flame retardancy was obtained. In conclusion, the incorporation of phosphorus compounds into the epoxy chain resulted in improved properties such as impact strength and heat resistance, as well as a significant increase in flame retardancy.


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