An efficiently halogen-free flame-retardant long-glass-fiber-reinforced polypropylene system

Abstract In order to solve the “candlewick effect” caused by glass fibers, which results in the decrease of flame retardancy of flame-retardant long-glass-fiber-reinforced polypropylene (LGFPP) systems, and the deterioration of mechanical properties caused by adding an additional amount of flame retardants compared with flame-retardant non-glass-fiber-reinforced polypropylene systems so as to keep a same flame retardancy, a novel intumescent flame retardant (IFR) system, which is composed of a charring agent (CA), ammonium polyphosphate (APP) and organically-modified montmorillonite (OMMT), was used to flame retard LGFPP. The thermal stability, combustion behavior, char formation, flame retardant mechanism and mechanical properties of the IFR-LGFPP samples were investigated by thermogravimetric analysis (TGA), limiting oxygen index (LOI), UL-94 test, cone calorimeter test, scanning electronic microscopy, and mechanical property tests. When the content of IFR is 20 wt%, the LOI value of IFR-LGFPP reaches 31.3, and the vertical burning test reaches UL-94 V-0 rating, solving the “candlewick effect” caused by long glass fiber without additional amount of the IFR. All the relevant cone calorimeter parameters also show that IFR-LGFPP has much better flame-retardant behaviors than LGFPP. Furthermore, the mechanical properties of IFR-LGFPP almost remain unchanged in comparison with those of LGFPP containing no IFR. The flame retardant mechanism was also discussed.

[1]  Miaojun Xu,et al.  Effect of a novel charring–foaming agent on flame retardancy and thermal degradation of intumescent flame retardant polypropylene , 2006 .

[2]  Uday K. Vaidya,et al.  Performance of long fiber reinforced thermoplastics subjected to transverse intermediate velocity blunt object impact , 2005 .

[3]  J. Gu,et al.  A new intumescent flame-retardant: preparation, surface modification, and its application in polypropylene , 2008 .

[4]  Yu-Zhong Wang,et al.  A novel halogen-free flame retardant for glass-fiber-reinforced poly(ethylene terephthalate) , 2008 .

[5]  T. R. Hull,et al.  Fire retardancy of a reactively extruded intumescent flame retardant polyethylene system enhanced by metal chelates , 2007 .

[6]  B. Li,et al.  Investigation on interfacial interaction of flame retarded and glass fiber reinforced PA66 composites by IGC/DSC/SEM , 2008 .

[7]  Qi Wang,et al.  Melamine cyanurate-microencapsulated red phosphorus flame retardant unreinforced and glass fiber reinforced polyamide 66 , 2006 .

[8]  Bernhard Schartel,et al.  Development of fire‐retarded materials—Interpretation of cone calorimeter data , 2007 .

[9]  F. Gao,et al.  Effect of a novel phosphorous–nitrogen containing intumescent flame retardant on the fire retardancy and the thermal behaviour of poly(butylene terephthalate) , 2006 .

[10]  Yu-Zhong Wang,et al.  The synergistic flame-retardant effect of O-MMT on the intumescent flame-retardant PP/CA/APP systems , 2010 .

[11]  Qi Wang,et al.  Preparation, properties and characterizations of halogen-free nitrogen–phosphorous flame-retarded glass fiber reinforced polyamide 6 composite , 2006 .

[12]  E. Bravin,et al.  Application of cone calorimeter for the assessment of class of flame retardants for polypropylene , 1998 .

[13]  B. Kandola,et al.  Mechanical performance of heat/fire damaged novel flame retardant glass - reinforced epoxy composites , 2003 .

[14]  Uday K. Vaidya,et al.  Process simulation, design and manufacturing of a long fiber thermoplastic composite for mass transit application , 2008 .

[15]  Zhi-Qiang Feng,et al.  Flame retarding glass fibers reinforced polyamide 6 by melamine polyphosphate/polyurethane‐encapsulated solid acid , 2007 .

[16]  Yu-Zhong Wang,et al.  Synthesis and characterization of a novel nitrogen‐containing flame retardant , 2004 .

[17]  Matthew F. Bundy,et al.  Cone calorimeter analysis of UL‐94 V‐rated plastics , 2007 .

[18]  N. Bhatnagar,et al.  Mechanical Properties of Injection Molded Long Fiber Polypropylene Composites, Part 2. Impact and Fracture Toughness , 2008 .

[19]  N. Bhatnagar,et al.  Mechanical properties of injection molded long fiber polypropylene composites, Part 1: Tensile and flexural properties , 2007 .

[20]  Yu-Zhong Wang,et al.  A Novel Intumescent Flame‐Retardant Polyethylene System , 2006 .

[21]  S. Bourbigot,et al.  Combustion behaviour of ethylene vinyl acetate copolymer‐based intumescent formulations using oxygen consumption calorimetry , 1998 .