Clariant launches high-efficiency halogen-free flame retardants for transport and construction

2012 ◽  
Vol 2012 (5) ◽  
pp. 2-3
Keyword(s):  
Flame Retardants ◽  
High Efficiency ◽  
Halogen Free

Conductive Filament Formation in Printed Circuit Boards – Effects of Reflow Conditions and Flame Retardants

2009 ◽  
Author(s):  
Bhanu Sood ◽  
Michael Pecht
Keyword(s):  
Flame Retardants ◽  
Printed Circuit Boards ◽  
Electrochemical Process ◽  
Lead Free ◽  
Circuit Boards ◽  
Filament Formation ◽  
Conductive Filament ◽  
Printed Circuit ◽  
Free Solder ◽  
Halogen Free

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.

Fire performance of brominated and halogen-free flame retardants in glass-fiber reinforced poly(butylene terephthalate)

2017 ◽  
Vol 42 (1) ◽  
pp. 18-27 ◽  
Author(s):  
M. Suzanne ◽  
A. Ramani ◽  
S. Ukleja ◽  
M. McKee ◽  
J. Zhang ◽  
...  
Keyword(s):  
Glass Fiber ◽  
Flame Retardants ◽  
Fire Performance ◽  
Fiber Reinforced ◽  
Butylene Terephthalate ◽  
Glass Fiber Reinforced ◽  
Halogen Free

scholarly journals Excellent Fireproof Characteristics and High Thermal Stability of Rice Husk-Filled Polyurethane with Halogen-Free Flame Retardant

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1587 ◽  
Author(s):  
Huong T.Q. Phan ◽  
Binh T. Nguyen ◽  
Lam H. Pham ◽  
Chi T. Pham ◽  
Thi Vi Vi Do ◽  
...  
Keyword(s):  
Rice Husk ◽  
Flame Retardants ◽  
Standard Test ◽  
Solid Particles ◽  
Cone Calorimetry ◽  
Thermal Stabilities ◽  
Pyrolysis Products ◽  
Halogen Free ◽  
Flame Retardancy Mechanism ◽  
Thermal Stability Of

The thermal stabilities, flame retardancies, and physico-mechanical properties of rice husk-reinforced polyurethane (PU–RH) foams with and without flame retardants (FRs) were evaluated. Their flammability performances were studied by UL94, LOI, and cone calorimetry tests. The obtained results combined with FTIR, TGA, SEM, and XPS characterizations were used to evaluate the fire behaviors of the PU–RH samples. The PU–RH samples with a quite low loading (7 wt%) of aluminum diethylphosphinate (OP) and 32 wt% loading of aluminum hydroxide (ATH) had high thermal stabilities, excellent flame retardancies, UL94 V-0 ratings, and LOIs of 22%–23%. PU–RH did not pass the UL94 HB standard test and completely burned to the holder clamp with a low LOI (19%). The cone calorimetry results indicated that the fireproof characteristics of the PU foam composites were considerably improved by the addition of the FRs. The proposed flame retardancy mechanism and cone calorimetry results are consistent. The comprehensive FTIR spectroscopy, TG, SEM, and XPS analyses revealed that the addition of ATH generated white solid particles, which dispersed and covered the residue surface. The pyrolysis products of OP would self-condense or react with other volatiles generated by the decomposition of PU–RH to form stable, continuous, and thick phosphorus/aluminum-rich residual chars inhibiting the transfer of heat and oxygen. The PU–RH samples with and without the FRs exhibited the normal isothermal sorption hysteresis effect at relative humidities higher than 20%. At lower values, during the desorption, this effect was not observed, probably because of the biodegradation of organic components in the RH. The findings of this study not only contribute to the improvement in combustibility of PU–RH composites and reduce the smoke or toxic fume generation, but also solve the problem of RHs, which are abundant waste resources of agriculture materials leading to the waste disposal management problems.

scholarly journals Self-Extinguishing Resin Transfer Molding Composites Using Non-Fire-Retardant Epoxy Resin

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2554 ◽  
Author(s):  
Zhi Geng ◽  
Shuaishuai Yang ◽  
Lianwang Zhang ◽  
Zhenzhen Huang ◽  
Qichao Pan ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Flame Retardants ◽  
Resin Transfer Molding ◽  
Fire Retardant ◽  
Functional Materials ◽  
Building Blocks ◽  
Fire Retardancy ◽  
Limiting Oxygen Index ◽  
Transfer Molding ◽  
Halogen Free

Introducing fire-retardant additives or building blocks into resins is a widely adopted method used for improving the fire retardancy of epoxy composites. However, the increase in viscosity and the presence of insoluble additives accompanied by resin modification remain challenges for resin transfer molding (RTM) processing. We developed a robust approach for fabricating self-extinguishing RTM composites using unmodified and flammable resins. To avoid the effects on resin fluidity and processing, we loaded the flame retardant into tackifiers instead of resins. We found that the halogen-free flame retardant, a microencapsulated red phosphorus (MRP) additive, was enriched on fabric surfaces, which endowed the composites with excellent fire retardancy. The composites showed a 79.2% increase in the limiting oxygen index, a 29.2% reduction in heat release during combustion, and could self-extinguish within two seconds after ignition. Almost no effect on the mechanical properties was observed. This approach is simple, inexpensive, and basically applicable to all resins for fabricating RTM composites. This approach adapts insoluble flame retardants to RTM processing. We envision that this approach could be extended to load other functions (radar absorbing, conductivity, etc.) into RTM composites, broadening the application of RTM processing in the field of advanced functional materials.

Detection of the Intermediates in Preparation of Ammonium Polyphosphate by Temperature Raising Rate Factor

2013 ◽  
Vol 275-277 ◽  
pp. 1654-1657
Author(s):  
Yue Long Liu ◽  
Gou Sheng Liu
Keyword(s):  
Reaction Mechanism ◽  
Industrial Production ◽  
Flame Retardants ◽  
Ammonium Polyphosphate ◽  
Reaction Process ◽  
Halogen Free ◽  
Internal Relationships ◽  
Controllable Preparation

Detection of intermediates is the general way to investigate a reaction mechanism, because the intermediates connect the reactants and the products, the intermediates can reflect some internal relationships between the reactants and the products. By studying the the structures of intermediates, the reaction process and reaction mechanism can thus be understood. Ammonium polyphosphate (APP) is an effective material as halogen-free flame retardants, it has six crystalline forms.In preparation of APP, the factor of temperature raising rate is investigated, some intermediates are detected, the XRD spectra of these intermediates are discussed. The results are informative for controllable preparation of APP in industrial production.

Preparation and Properties of Halogen-Free Flame Retardant Polyurethane Foams

2011 ◽  
Vol 418-420 ◽  
pp. 540-543 ◽  
Author(s):  
Ding Meng Chen ◽  
Yi Ping Zhao ◽  
Jia Jian Yan ◽  
Li Chen ◽  
Zhi Zhi Dong ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Flame Retardants ◽  
Oxygen Index ◽  
Mechanical Analysis ◽  
Polyurethane Foams ◽  
Dimethyl Methylphosphonate ◽  
Limiting Oxygen Index ◽  
Layer Composite ◽  
Halogen Free ◽  
Thermal Stable

Polyurethane foams (PUFs) filled with several halogen-free flame retardants and composite halogen-free flame retardants were prepared. The flame retardant, thermal stable and mechanical properties of the PUFs were investigated. The results of limiting oxygen index (LOI) and thermogravimetric analysis (TGA) revealed that PUFs filled with dimethyl methylphosphonate (DMMP) had better flame retardancy compared with other flame retardants and DMMP degraded at a low temperature to form several phosphorated acids which accelerated the formation of char layer. Composite flame retardant of DMMP and melamine (MA) had a synergistic effect between phosphorus and nitrogen. The combination of DMMP and MA slightly altered the density of the PUFs. Results from the mechanical analysis revealed that with the increase in concentration of MA in the composite flame retardant of DMMP and MA, the tensile strength of PUFs reduced firstly and then increased up to a constant.

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