Commercial epoxy resin loaded with phosphorus flame retardant led to composites exhibiting remarkable improved flame retardancy and thermal stability.

The aim of the present study was to obtain high-performance materials for heat and flame protective clothing. Therefore, hybrid membranes were prepared using Kevlar as support and aromatic polyimide nanofibers as a protective coating. The exceptional performances of the prepared membranes were highlighted by selected indicators: high thermal stability, fire resistance and improvement in air permeability without modifying drastically the water vapor transmission rate properties. Attenuated total reflectance Fourier transform infrared and 1H nuclear magnetic resonance spectroscopy were employed to confirm polyimide formation. The ability of polyimide to form fibers was investigated by rheological measurements and scanning electron microscopy, respectively. Thermal degradation was studied using thermogravimetric analysis and a microscale combustion calorimeter. The transport properties of the materials were examined by air permeability, water vapor transmission rate and water resistance. It was shown that transport properties of the modified Kevlar membranes could be controlled by varying the spinning time of polyimide solution. Moreover, by annealing the modified Kevlar weavings at 260℃, the structural integrity and transport properties were not affected, whereas a higher resistance to water was found.

A series of thermotropic liquid crystalline aliphatic–aromatic copolyesters derived from various ratios of dodecane‐1,12‐diol (1), terephthaloyl bis‐(4‐oxybenzoyl‐chloride) (2), and 2‐(6‐oxido‐6H‐dibenz〈c,e〉〈1,2〉 oxaphosphorin‐6‐yl)‐1,4‐naphthalene diol (3), has been synthesized. The chemical structures of the monomers and polymers have been confirmed by elemental analyses, and FT‐IR and 1H NMR spectroscopy. The mesomorphic properties of polymers have been investigated by differential scanning calorimetry, polarizing optical microscopy, and X‐ray diffraction measurements. The influence of the content of the aliphatic unit on the phase behavior of the polymers has been examined. The polymers that contain >30 mol‐% aliphatic diol showed smectic phases while the polymers that contained <30 mol‐% aliphatic diol displayed nematic phases. The polymers revealed a reversible mesomorphic phase transition, wide mesophase temperature ranges, and high thermal stability. The degree of crystallinity increased upon increasing the content of aliphatic moieties. The char yield at high temperature increased by increasing the content of phosphorous‐containing bisphenol.magnified image

New fire resistant epoxy resins were prepared. The kinetic processing of thermogravimetric data was performed using Friedman and Vyazovkin methods.

Chemical modification of a chloromethylated polysulfone (CMPS) was performed by reacting the chlorometyl group with PH bond of 9,10‐dihydro‐oxa‐10‐phosphophenanthrene‐10‐oxide (DOPO). A kinetic study of phosphorylation of CMPS with different chlorine content was reported. The obtained polymers bearing cyclic bulky groups containing phosphorus were characterized by analytical methods; Fourier transforms spectroscopy (FTIR), and nuclear magnetic resonance spectroscopy (NMR). The thermal stability of phosphorus‐modified polysulfone was evaluated by dynamic thermogravimetric analysis in nitrogen gas. The polymers were readily soluble in polar organic solvent, such as N‐methylpyr‐rolidone (NMP), N,N‐dimethylacetamide (DMAc), and N,N‐dimethylformamide (DMF). Differential scanning calorimeter (DSC) and dynamic mechanical analysis (DMA) proved an amorphous morphology of these polymers. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers