Manufacturing,thermal stability,and flammability properties of polypropylene containing new single molecule intumescent flame retardant

Melamine salt of pentaerythritol phosphate kaolin (MPPK) was synthesized by the reaction of pentaerythritol phosphate with kaolin (K) and melamine. The structure of MPPK was confirmed by EDXS, ¹H NMR, FTIR, and XRD. MPPK was blended with polypropylene (PP) at different loading levels. Thermogravimetric analysis (TGA) results showed that MPPK improved the thermal stability of PP at high temperatures in all PP composites. Vertical burning rate test manifested that PP composites can achieve V0 at 20% and 25% MPPK loading levels. Cone calorimeter data exhibited that addition of 25% MPPK to PP reduced peak of heat release rate (pHRR) and total heat release (THR) by 86% and 76% and increased the char residue after test to 67%. The results of PP/25% MPPK composite were compared with the data obtained from PP containing 25% K and 25% of traditional intumescent flame retardant composed of melamine phosphate (MP), pentaerythritol (PE), and K. The outcomes indicated that MPPK was more efficient in flame retardancy than the other systems. The digital photographs and SEM images for char residue demonstrated that MPPK succeeded in forming cellular and coherent char layer on the PP surface. The main advantage of adding 25% MPPK to PP was its ability to preserve nearly the inner half of the sample without burning after cone calorimeter test.     

Synthesis of a novel highly efficient flame-retardant coating for cotton fabrics with low combustion toxicity and antibacterial properties

Cellulose - The synthesis of multi-function flame retardants is widely increasing to fulfill industrial and economic goals. In this work, a novel flame retardant, melamine salt of tannic phosphate...     

Effect of iron poly(acrylic acid-co-acrylamide) and melamine polyphosphate on the flammability properties of linear low-density polyethylene

Journal of Thermal Analysis and Calorimetry - This research is exhibited to visualize the squeezed flow of magneto-nanoliquid between two parallel disks. Transportations of heat and mass are...     

Hidden Genes Genetic Optimization for Variable-Size Design Space Problems

This paper introduces the biologically inspired concept of hidden genes genetic algorithms; they search for optimal solutions to global optimization problems of multimodal objective functions with a variable number of design variables. A fixed chromosome length is assumed for all solutions in the population. Each chromosome is divided into effective and ineffective segments. The effective segment includes the design variables for that solution. The ineffective segment includes only hidden genes. Hidden genes are excluded in objective function evaluations. The effect of the hidden genes on the convergence of the genetic algorithm is studied. Two test cases are presented.     

N‐Azolylmethyl ketones as building blocks in heterocyclic synthesis: Synthesis of new polyfunctionally substituted azolylarylazophenols,azolylpyridones and azolylthiophenes

The title compounds 1a‐b and 2 reacted with 2‐arylhydrazonopropanals 3a‐c to yield polyfunctionally substituted azolylarylazophenols 5 and 8. The reaction of 1b and 2 with phenylisothiocyanate in the presence of α‐haloketones afforded the azolylthiophenes 12a,b and 13a,b. The reaction of 20 with α‐haloketone afforded 5‐benzotriazol‐1‐yl‐6‐methyl‐2‐(2‐oxopropylsulfanyl)nicotinonitrile 21 that was utilized as building blocks for the synthesis of condensed pyridines. Compound 21 was condensed with dimethylformamide dimethylacetal to yield thieno[2,3‐b]pyridin‐3‐yl‐N, N‐dimethylformamidine derivative 22. This was further cyclized with sodium hydride to 1H‐fhieno[2,3‐b; 4,5‐b']dipyridin‐4‐one derivative 23.     

Enaminones as building blocks in heterocyclic syntheses: A new approach to polyfunctionally substituted cyclohexenoazines

A variety of polyfunctionally substituted condensed pyridines and pyrazolotetrahydroquinazolines have been synthesized utilizing cyclic enaminones as starting materials.     

Pyrolytic behavior of substituted N‐aminoheteroaromatics: Synthesis of pyrazolo[1,5‐a]pyridine and 3‐substituted 3‐oxopropionitrile derivatives

Flash vacuum pyrolysis (FVP) of 1,7‐bis‐(3‐aroylideneamino)‐4,6,10,12‐tetramethyl‐2,8‐dioxo‐1,7‐diazacyclododeca‐3,5,9,11‐tetraene‐3,9‐dicarbonitriles 11a‐c at 650°C and 0.02 Torr yielded 5,7‐dimethyl‐3‐(4‐methylbenzoyl)‐pyrazolo[1,5‐a]pyridine‐4‐carbonitrile 14 , 4,6‐dimethyl‐2‐oxo‐1,2‐dihydropyridine‐3‐carbonitrile 16 and 3‐aryl‐3‐oxo‐propionitriles 17a,b . A plausible mechanism is suggested to account for the formation of the products.     

Gas‐phase pyrolysis in organic synthesis: New route for synthesis of functionally substituted imidazoles

1,2,3‐Triazolylpropanone was prepared and coupled with aryldiazonium salts yielding the corresponding arylhydrazones. Gas‐phase pyrolysis of the hydrazono derivative produced N‐arylamino‐2‐acetylimidazole as well as 2‐acetylimidazole. The latter is the product of further pyrolysis of the former.