Study on the properties of polyamide 6 blended with melamine polyphosphate and layered silicates

Agro waste as a potential carbon feedstock for poly-3-hydroxy alkanoates production: Commercialization potential and technical hurdles

The enormous production and widespread applications of non -biodegradable plastics lead to their accumulation and toxicity to animals and humans. The issue can be addressed by the development of eco-friendly strategies for the production of biopolymers by utilization of waste residues like agro residues. This will address two societal issues - waste management and the development of an eco-friendly biopolymer, poly-3-hydroxy alkanoates (PHAs). Strategies adopted for utilization of agro-residues, challenges and future perspectives are discussed in detail in this comprehensive review. The possibility of PHA properties improvements can be increased by preparation of blends.

Silicon/nitrogen synergistically reinforced flame-retardant PA6 nanocomposites with simultaneously improved anti-dripping and mechanical properties

A facile route of ‘copolymerization/blending’ was proposed to fabricate silicon/nitrogen synergistically reinforced flame-retardant PA6 nanocomposites with simultaneously improved anti-dripping and mechanical properties. Firstly, a persistently inherent flame-retardant PA6 (FR-PA6), with 1,3-bis(3-aminopropyl)tetramethyl disiloxane (MSDS), was synthesized via controllable amidation and a polycondensation reaction. Melamine cyanurate (MCA) nanoparticles as a ‘gas phase’ synergistic agent were then added into FR-PA6 to further improve its flame retardancy. The primarily obtained FR-PA6 could be extinguished after a few melt droplets dropped as ignited, and passed the V-2 rating with enhanced mechanical properties, while PA6 had no rating (NR). The prepared FR-PA6/MCA nanocomposites could attain a limiting oxygen index (LOI) value of 32.7%, and passed the V-0 level with only 1 melting droplet with similar mechanical properties to PA6. Accordingly, the special ‘condensed-gas phase’ synergistic flame-retardant mechanism of FR-PA6/MCA nanocomposites was proposed through studying the residues and pyrolysis volatiles. This work provided a facile route as a model for developing functional PA6 for diverse engineering applications.

A facile route was provided to prepare silicon/nitrogen synergistically reinforced flame-retardant PA6 nanocomposites with simultaneously improved anti-dripping and mechanical properties.

Effects of α-ZrP on Crystallinity and Flame-Retardant Behaviors of PA6/MCA Composites

Novel flame-retardant Polyamide6/Melamine cyanurate-alpha-zirconium phosphate (PA6/MCA-α-ZrP) composites were prepared via the incorporation of the modified MCA (MCA-α-ZrP) into PA6. MCA-α-ZrP were synthesized through the self-assembly of α-ZrP, Melamine (ME), and cyanuric acid (CA) molecules. The results of differential scanning calorimetry (DSC) and X-ray diffraction (XRD) showed that the incorporation of enough α-ZrP (30 wt% MCA) caused the increased crystallinity of PA6 and tended to form γ phase. The thermogravimetric analysis (TGA) and heat distortion temperature (HDT) test illustrated that the α-ZrP could increase the residue and HDT values of PA6/MCA and showed a synergistic effect with MCA. The combination of MCA and α-ZrP caused the enhancement of vertical burning test (UL-94) rating. Cone calorimeter test (CCT) gave clear evidences that PA6/MCA-10α-ZrP composites with low heat release rate (HRR), low total heat release (THR), and high amounts of char residues after combustion compared with PA6/MCA and PA6/MCA-30α-ZrP. What is more, excellent mechanical properties were kept even though MCA and α-ZrP were dispersed not as good as expected.