Organic Flame Retardants Research Articles

Chemistry of green encapsulating molding compounds at interfaces with other materials in electronic devices

The interface chemistry between encapsulating epoxy phenolic molding compound (EMC) containing phosphorous based organic flame retardant (the so called “green materials”) and copper oxide–hydroxide and aluminum oxide–hydroxide surfaces have been studied in comparison with “conventional” EMC containing bromine and antimony as flame retardant. These green materials are designed to reduce the presence of toxic elements in the electronic packages and, consequently, in the environment. For the study were used a Scanning Acoustic Microscopy for delamination measurements, a dynamometer for the pull strength measurements and an ESCA spectrometer for chemical analysis of the interface. The general behavior of the green compound in terms of delamination, adhesion, and corrosion is found better or at least comparable than that of the conventional EMC.

PBCDD and PBCDF from incineration of waste-containing brominated flame retardants.

Brominated organic flame retardants comprise a large, heterogeneous group of compounds that are useful but also potentially damaging to the environment. In this investigation, three common brominated flame retardants were co-combusted with an artificial municipal solid waste in a pilot-scale fluidized bed incinerator. Combustion conditions ensured degradation of the flame retardants, but stable brominated organic compounds such as polybrominated dibenzo-p-dioxins and polybrominated dibenzofurans were formed in the cooling flue gases. The incineration of fuels that contain both chlorine and bromine leads to the formation of a complex mixture of polybrominated/chlorinated dibenzo-p-dioxins and dibenzofurans. More bromination than chlorination was observed in these experiments, and the chlorination levels increased when bromine was added to the fuel. The most favored reactions led to the formation of dibromodichlorodibenzo-p-dioxin and dibromodichlorodibenzofuran. Theoretical calculations show that there is more Br2 than Cl2 in the flue gas when the two halogens are present at equimolar levels, because chlorine is mainly found in the form of HCl. This may explain the higher bromination level. BrCl is also present, which drives the chlorination observed when bromine is added.

Flame Retardancy in UL-94 V-0 and in UL-94 5VA High Impact Polystyrene

The feasibility of producing HIPS of UL-94 5V flammability rating has been demonstrated. Results of TGA, XRD and SEM enable the role of such components as brominated organic flame retardant, antimony trioxide, chlorin ated polyethylene and magnesium hydroxide in flame retardancy of 5VA HIPS to be evaluated.

PBDF and PBDD from the combustion of bromine containing flame retarded polymers: A survey

The formation of polybrominated dibenzofurans (PBDF) and dibenzodioxins (PBDD) during the pyrolysis of different polymers containing brominated organic flame retardants was investigated. The pyrolyses were conducted at two different temperatures (600°C and 800°C) using three different oven configurations. Both the pyrolysis gases and the solid residues were analysed for PBDF and PBDD. PBDF were found in almost all samples, but both the concentration and the degree of bromination varied greatly. The largest yields of PBDF in the percent range were measured in the pyrolysis products of polymers containing brominated diphenyl ethers. The other flame retardants generally yielded only a few ppm of PBDF. PBDD are formed only in a few samples and related to the PBDF in very low concentrations.

The formation of antimony oxychloride in flame retardant mixtures and its influence on flame retardant efficiency

Interaction of Sb 2O 3 with HCl vapour and chlorine-containing organic flame retardants in the presence and absence of polymers (polypropylene, polyethylene) has been studied at 473–773 K. It has been shown that SbOCl is formed in thermally degrading mixtures in the condensed phase. The influence of SbOCl formation on flame retardant efficiency is discussed.

Innovation in Flame and Heat Resistant EPDM Formulations

Abstract A series of experiments on the flammability of EPDM formulations which contained a minimum amount (30 phr) of aromatic organic flame retardant (DBDO) revealed that increasing the crosslink density increased the flame resistance. This was especially true when the formulations were cured by a combination of DCP, TAIC, and HVA-2. The best result was obtained in a formulation which was cured by DCP/TAIC/HVA-2 at 2.5/1.0/0.5 phr, respectively. This material had excellent physical properties that would be well suited for use in the wire and cable industry. It was also found that good dispersion of individual ingredients was needed to obtain optimum flame resistance.