Preparation and characterization of polypyrrole/clinoptilolite nanocomposite with enhanced electrical conductivity by surface polymerization method

Facile Construction of Polypyrrole Microencapsulated Melamine-Coated Ammonium Polyphosphate to Simultaneously Reduce Flammability and Smoke Release of Epoxy Resin

A unique mono-component intumescent flame retardant, named PPy-MAPP, of which melamine-coated ammonium polyphosphate (MAPP) was microencapsulated by polypyrrole (PPy), was synthesized and carefully characterized. The obtained PPy-MAPP was applied to epoxy resin (EP) for obtaining flame-retarded EP composites. The results show that PPy-MAPP imparts better flame retardancy and smoke suppression properties to EP compared to the same addition of MAPP. The EP composite with 15 wt% PPy-MAPP easily passes the UL94 V-0 rating and achieves an LOI value of 42.4%, accompanied by a 61.9% reduction in total heat release (THR) and a 73.9% reduction in total smoke production (TSP) when compared with pure EP. The char residue analysis shows that PPy-MAPP can promote a generation of more phosphorus-rich structures in the condensed phase that improve the integrity and intumescence of char against fire. The mechanical test indicates that PPy-MAPP has a less negative effect on the tensile strength and elastic modulus of epoxy resin due to the good compatibility between PPy-MAPP and the EP matrix, as supported by differential scanning calorimetry (DSC) analyses. In this paper, these attractive features of PPy-MAPP provide a new strategy to prepare satisfactory flame retardant and super flame retarding EP composites.

Swelling Properties and Environmental Responsiveness of a Superabsorbent Composite Microsphere Based on Starch-g-Poly(acrylic acid)/Organo-Mordenite

Starch-g-poly(acrylic acid)/organo-mordenite superabsorbent composite microsphere, was prepared by grafting partially neutralized acrylic acid onto starch in the presence of organo-mordenite as an inorganic component. The morphology was characterized with scanning electron microscope (SEM). The swelling properties of the superabsorbent composite microsphere were evaluated in distilled water, various NaCl solutions, solutions with different pH values, and urea solutions. Swelling kinetics of the superabsorbent composite microsphere in above environments were discussed by means of a Schott's second-order model. The results showed that the incorporation of 10 wt% organo-mordenite enhanced the water absorbency by 144% (from 268 to 655 g · g−1) and possessed the maximum swelling absorbency (75 g · g−1) in the 0.9% NaCl solution and (667 g · g−1) in 0.04 mol · l−1 urea solution. Moreover, swelling of starch-g-poly(acrylic acid)/organo-mordenite (with 10 wt% organo-mordenite) in distilled water and in all other environments followed Schott's second order kinetics. Swelling was extremely environmental-responsive to the concentration of the NaCl solution, the pH values, and urea solutions, respectively. The overall results inferred that the novel superabsorbent composite can be exploited for many potential applications.

Conductive polymers/zeolite (nano-)composites: under-exploited materials

This review provides a snapshot of recent progress in the synthesis, materials properties, and applications of conductive polymers/zeolite (nano-)composites reported until March 2014.