Preparation and characterization of flame‐retardant melamine cyanurate/polyamide 6 nanocomposites by in situ polymerization

Abstract

This article focuses on an improved method, i.e., improved in situ polymerization of e-caprolactam in the presence of melamine derivatives to prepare flameretardant melamine cyanurate/polyamide 6 (MCA/PA6) nanocomposites. The chemical structures of these synthetic flame retardant composites are characterized by Fouriertransform infrared spectroscopy and X-ray diffraction. Morphologies, mechanical properties, and thermal properties also are investigated by the use of transmission electron microscopy, mechanical testing apparatus, differential scanning calorimetry, and thermogravimetric analysis, respectively. Through transmission electron microscopy photographs, it can be found that the in situ-formed MCA nanoparticles with diametric size of less than 50 nm are nanoscaled, highly uniformly dispersed in the PA6 matrix. These nanocomposites, which have good mechanical properties, can reach UL-94 V-0 rating at 1.6-mm thickness even at a relatively low MCA loading level.

Aluminum hypophosphite microencapsulated to improve its safety and application to flame retardant polyamide 6

“…It clearly shows that the initial decomposition temperature of FR-PA6 composites is lower than pure PA6. This phenomenon can be primary attributed to that the capsule material MCA presents lower thermal degradation temperature and causes weak bond-breakage degradation through the interaction between amide groups of PA6 and melamine or cyanuric acid [34,35]. The second stage mainly arises from the decomposition of AHP and the reaction of these decomposed products between AHP and PA6 [13,14].…”

Investigation of thermal degradation characteristics of polyamide-6 containing melamine or melamine cyanurate via direct pyrolysis mass spectrometry

“…There have been several studies on flammability and thermal degradation of polyamide-6 composites containing melamine or melamine cyanurate [17][18][19][20][21][22][23][24][25][26][27]. Generally, PA6 decomposes primarily into caprolactam, alkyl cyanides and ammonia.…”

“…It has been determined that addition of 20% melamine or 15% melamine cyanurate increases LOI value 22.5-31. Although, in situ polymerization of e-caprolactam in the presence of melamine derivatives yielded flame retardant melamine cyanurate/polyamide 6 nanocomposites with better flame retarding ability, the thermal stability and mechanical properties were destroyed by increasing the melamine cyanurate content [22].…”

Micro-intumescent flame retardant polyamide 6 based on cyclic phosphate grafting phenol formaldehyde

“…Lots of these applications require flame retardancy, and hence developing PA6 with good flame retardant performance has attracted much attention. [1,2] The flame retardancy of PA6 was achieved by the incorporation of halogen-containing compounds formerly; however, for the sake of safety and environmental concerns, [3] more and more applications have resorted to non-halogenated flame retardants. So far the majority of the non-halogenated alternatives are based on nitrogen, phosphorus, silicon and metal hydroxides and nanoparticles etc., [4][5][6][7][8][9][10][11][12][13][14][15] for example, melamine cyanurate (MCA), [4] Mg(OH) 2 , [5] red phosphorus, [6,7] melamine polyphosphate (MPP) [8,9] and metal dialkyl-phosphinates (MDAP).…”