Surface Modification of Carbon Microspheres with Guanidine Phosphate and Its Application as a Flame Retardant in PET.

Shan Jiang,Dan Zha,Yonghong Ding,Qiang Yu,Dun Wu,Cheng Ji

doi:10.3390/polym12081689

Abstract

Composites based on polyethylene terephthalate (PET) and surface-modified carbon microspheres (CMSs) were prepared by melt mixing. The surface modification of CMSs was conducted with low-temperature plasma technology first, and a phosphorus-nitrogen flame retardant, guanidine phosphate (GDP), was then grafted onto CMSs. The modification of CMSs was done to improve both the filler dispersity in the PET matrix and the flame-retardant performance of composites. The obtained CMSs-GDP was characterized by FTIR spectra and a scanning electron microscope (SEM). The grafting ratio was characterized and calculated by thermal gravimetric analysis (TGA). The grain size analysis was used to describe the dispersity of CMSs. The mechanical properties of the PET/CMSs-GDP composite were measured using a universal testing machine. The PET/CMSs-GDP composite can achieve a limiting oxygen index (LOI) value of 32.4% and a vertical burning test (UL94) V-0 rating at 3% CMSs-GDP loading.

Highlights

Flame retardants for polyethylene terephthalate (PET) have been a constant research hotspot.The commonly reported flame retardants used with PET can be divided into various kinds, such as traditional halogen-containing flame retardants, intumescent flame retardants, and inorganic nanometer fire retardants [1]
Cai [4] studied the effects of laminated metal lanthanum phenyl phosphonate (LaPP) on the thermal stability, flame retardation characteristics, and mechanical properties of a PET/microcapsule red phosphorus system (PET/GF-MRP) reinforced by glass fiber, whose limiting oxygen index (LOI) can reach 28.9%
Incorporated a flame-retardant system consisting of 1-hydroxymethyl-1, 1-diphosphate (HEDP) and ammonium sulfamate into polyester fabric for flame retardation; the LOI was increased to 28%, and the results showed that the PET composite material can achieve the UL94-V0 level

Summary

Introduction

Flame retardants for polyethylene terephthalate (PET) have been a constant research hotspot. The commonly reported flame retardants used with PET can be divided into various kinds, such as traditional halogen-containing flame retardants, intumescent flame retardants, and inorganic nanometer fire retardants [1]. With recent stricter requirements for safety and environmental protection, the development of halogen flame retardants has been limited [2]. Many new inorganic nanometer halogen-free and intumescent flame retardants have been synthesized [3]. Wu [5] used liquid bisphenol A, double (diphenyl phosphorous) (BDP) to pre-disperse, so that carbon nanotubes could be dispersed uniformly in PET by melting and blending, which can enhance the flame-retardant behavior.

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