scholarly journals Recent Developments in Halogen Free Flame Retardants for Epoxy Resins for Electrical and Electronic Applications

Materials ◽  
2010 ◽  
Vol 3 (8) ◽  
pp. 4300-4327 ◽  
Author(s):  
Muriel Rakotomalala ◽  
Sebastian Wagner ◽  
Manfred Döring
Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3901 ◽  
Author(s):  
Markwart ◽  
Battig ◽  
Velencoso ◽  
Pollok ◽  
Schartel ◽  
...  

The current trend for future flame retardants (FRs) goes to novel efficient halogen-free materials, due to the ban of several halogenated FRs. Among the most promising alternatives are phosphorus-based FRs, and of those, polymeric materials with complex shape have been recently reported. Herein, we present novel halogen-free aromatic and aliphatic hyperbranched polyphosphoesters (hbPPEs), which were synthesized by olefin metathesis polymerization and investigated them as a FR in epoxy resins. We compare their efficiency (aliphatic vs. aromatic) and further assess the differences between the monomeric compounds and the hbPPEs. The decomposition and vaporizing behavior of a compound is an important factor in its flame-retardant behavior, but also the interaction with the pyrolyzing matrix has a significant influence on the performance. Therefore, the challenge in designing a FR is to optimize the chemical structure and its decomposition pathway to the matrix, with regards to time and temperature. This behavior becomes obvious in this study, and explains the superior gas phase activity of the aliphatic FRs.


2020 ◽  
Vol 38 (6) ◽  
pp. 552-573
Author(s):  
Nikita Mishra ◽  
Dilip Vasava

Flame retardants are chemical compounds when mixed or incorporated in to polymers provide varying degrees of flammability protection. Flammable polymeric materials are ubiquitous with a wide array of applications. However, recent studies have shown potential environmental and health concerns with certain halogen-containing flame retardants. Thus, it has now become a necessity to explore new and effective materials that are safer and environmentally benign. In this context, halogen-free phosphorus- and nitrogen-containing flame retardants have attracted much attention worldwide. Moreover, s-triazine is the central focus because of its excellent charring effect. General strategies for synthesizing s-triazine compounds mostly via nucleophilic substitution reaction have been highlighted. This review provides a comprehensive description on design and synthesis of flame-retardant materials with significant flammability performance.


Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2145 ◽  
Author(s):  
Quanyi Liu ◽  
Donghui Wang ◽  
Zekun Li ◽  
Zhifa Li ◽  
Xiaoliang Peng ◽  
...  

With the increasing emphasis on environmental protection, the development of flame retardants for epoxy resin (EP) has tended to be non-toxic, efficient, multifunctional and systematic. Currently reported flame retardants have been capable of providing flame retardancy, heat resistance and thermal stability to EP. However, many aspects still need to be further improved. This paper reviews the development of EPs in halogen-free flame retardants, focusing on phosphorus flame retardants, carbon-based materials, silicon flame retardants, inorganic nanofillers, and metal-containing compounds. These flame retardants can be used on their own or in combination to achieve the desired results. The effects of these flame retardants on the thermal stability and flame retardancy of EPs were discussed. Despite the great progress on flame retardants for EP in recent years, further improvement of EP is needed to obtain numerous eco-friendly high-performance materials.


Author(s):  
Bhanu Sood ◽  
Michael Pecht

Abstract Failures in printed circuit boards account for a significant percentage of field returns in electronic products and systems. Conductive filament formation is an electrochemical process that requires the transport of a metal through or across a nonmetallic medium under the influence of an applied electric field. With the advent of lead-free initiatives, boards are being exposed to higher temperatures during lead-free solder processing. This can weaken the glass-fiber bonding, thus enhancing conductive filament formation. The effect of the inclusion of halogen-free flame retardants on conductive filament formation in printed circuit boards is also not completely understood. Previous studies, along with analysis and examinations conducted on printed circuit boards with failure sites that were due to conductive filament formation, have shown that the conductive path is typically formed along the delaminated fiber glass and epoxy resin interfaces. This paper is a result of a year-long study on the effects of reflow temperatures, halogen-free flame retardants, glass reinforcement weave style, and conductor spacing on times to failure due to conductive filament formation.


2011 ◽  
Vol 197-198 ◽  
pp. 1346-1349 ◽  
Author(s):  
Fa Chao Wu

Bis(2,6,7-trioxa-l-phosphabicyclo[2.2.2]octane-4-methanol) melaminium salt (Melabis) and microcapsules of Melabis with melamine resin shell as flame retardants (FR), respectively, were synthesized. Their structures were characterized by NMR, IR, SEM, TG and element analysis. 20% weight of microcapsules was doped into epoxy resins (EP) to get 28.5 % of LOI and UL 94 V-0. The heat and smoke release of EP containing microcapsules was valued by cone calorimeter.


2017 ◽  
Vol 42 (1) ◽  
pp. 18-27 ◽  
Author(s):  
M. Suzanne ◽  
A. Ramani ◽  
S. Ukleja ◽  
M. McKee ◽  
J. Zhang ◽  
...  

RSC Advances ◽  
2021 ◽  
Vol 11 (49) ◽  
pp. 30943-30954
Author(s):  
Wei Peng ◽  
Yu-xuan Xu ◽  
Shi-bin Nie ◽  
Wei Yang

Phosphorus-containing flame retardants have received huge interest for improving the flame retardant behavior of epoxy resins (EP) over the past few decades.


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