Development of Flame-Retarded Nanocomposites from Recycled PET Bottles for the Electronics Industry

Abstract

Recycled polyethylene-terephthalate (rPET) nanocomposites of reduced flammability were prepared by combining aluminum-alkylphosphinate (AlPi) flame retardant (FR) and natural montmorillonite (MMT), in order to demonstrate that durable, technical products can be produced from recycled materials. During the development of the material, by varying the FR content, the ratio and the type of MMTs, rheological, morphological, mechanical and flammability properties of the nanocomposites were comprehensively investigated. Related to the differences between the dispersion and nucleation effect of MMT and organo-modified MMT (oMMT) in rPET matrix, analyzed by Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS) and Differential Scanning Calorimetry (DSC), mechanical properties of the nanocomposites changed differently. The flexural strength and modulus were increased more significantly by adding untreated MMT than by the oMMT, however the impact strength was decreased by both types of nanofillers. The use of different type of MMTs resulted in contradictory flammability test result; time-to-ignition (TTI) during cone calorimeter tests decreased when oMMT was added to the rPET, however MMT addition resulted in an increase of the TTI also when combined with 4% FR. The limiting oxygen index (LOI) of the oMMT containing composites decreased independently from the FR content, however, the MMT increased it noticeably. V0 classification according to the UL-94 standard was achieved with as low as 4% FR and 1% MMT content. The applicability of the upgraded recycled material was proved by a pilot experiment, where large-scale electronic parts were produced by injection molding and characterized with respect to the commercially available counterparts.

Flame‐retardant poly (ethylene terephthalate) enabled by a novel melamine polyphosphate nanowire

“…Currently, halogen‐free flame‐retarded PET systems arouse more and more attention in flame‐retardant area. Flame retardants containing P, N, B, and Si elements are reported more environmental‐friendly and effective for PET material …”

“…B, and Si elements are reported more environmental-friendly and effective for PET material. [8][9][10][11] Melamine polyphosphate (MPP), an efficacious P-N flame retardant, is broadly applied in improving the flame retardance of poly (vinyl alcohol), polyamide 6,6, and epoxy resin because of its excellent thermal stability, low cost, and low smoke and toxicity. [12][13][14] Previously reported studies have demonstrated that MPP can act both in gaseous and condensed phases.…”

Nanoreinforcements of Two-Dimensional Nanomaterials for Flame Retardant Polymeric Composites: An Overview

“…With addition of 4% mass Co-OMt, 4% mass Co-OMt/IFR/PP nanocomposites have surpassed a UL-94 V-0 rating, with an LOI value as high as 32.1%. e use of MMT as a synergic additive to flame retardants for designing polymers with better flame-retardant properties has already been extensively studied [45,[153][154][155][156][157][158][159][160][161][162][163][164][165][166]. e effect of APP/zinc borate (ZB) for making highly efficient flame retardants and ceramics of ethylene-vinyl acetate/mica powder/organic modified montmorillonite (EVA/MP/OMMT) composites has been shown [166].…”

Melting temperature versus crystallinity: new way for identification and analysis of multiple endotherms of poly(ethylene terephthalate)

“…The usage of poly(ethylene terephthalate) (PET) still increases nowadays; in original form and as secondary raw material alike [1,2]. Besides the packaging industry, PET is increasingly used as a technical material thanks to the achievements of the material developments (Solid State Polycondensation reaction (SSP) or chain extender additives) and the advancements in the processing technologies (foam forming, 3D printing) [3][4][5][6][7]. Regarding applicability of the final products the mechanical properties are crucial, which are greatly affected by the morphology and crystalline structure formed during processing [8,9].…”