The Chemistry and Applications of Antimicrobial Polymers: A State-of-the-Art Review

Recent developments in the chemistry of halogen-free flame retardant polymers

The objective of this review is to make the field of “flame retardants for polymer materials” more accessible to the materials science community, i.e. chemists, physicists and engineers. We present the fundamentals of polymer combustion theory, the main flame retardant properties and tests used to describe fire behavior, together with the nature and modes of action of the most representative flame retardants and the synergistic effects that can be achieved by combining them. We particularly focus on polymer nanocomposites, i.e. polymer matrices filled with specific, finely dispersed nanofillers, which will undoubtedly pave the way for future materials combining physicochemical and thermo-mechanical performances with enhanced flame retardant behavior.

New prospects in flame retardant polymer materials: From fundamentals to nanocomposites

Polymer/layered silicate (clay) nanocomposites: An overview of flame retardancy

This paper reviews the research and development activities conducted over the past few decades on carbon fibers. The two most important precursors in the carbon fiber industry are polyacrylonitrile (PAN) and mesophase pitch (MP). The structure and composition of the precursor affect the properties of the resultant carbon fibers significantly. Although the essential processes for carbon fiber production are similar, different precursors require different processing conditions in order to achieve improved performance. The research efforts on process optimization are discussed in this review. The review also attempts to cover the research on other precursor materials developed mainly for the purpose of cost reduction.

https://www.mdpi.com/1996-1944/2/4/2369/pdf

Fabrication and Properties of Carbon Fibers

Conventional materials (natural and man-made fibres, plastics, wood, paper etc.) used in everyday life are, in different degrees, liable to ignition. This fact has impelled the development of new materials which are inherently resistant to flame and heat or to modify these materials by using flame-retardant additives/treatments to meet the stringent regulations set for fire protection. This paper gives an overview of the newly developed inherently flame-retardant fibres and engineering plastics specifically aramids, polyimides, polybenzimidazole, novoloid, polyphenylene sulphide and carbon fibres. The use of various additives and FR finishes has also been highlighted.

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Fire-retardant materials

With increasing awareness of environmental concerns, various chemical finishes for processing of textiles have been discussed. In this paper major changes which have occured to satisfy the consumer's demand in terms of comfort, easy care, health, and hygiene are reviewed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 631–659, 2002

Finishing of textile materials

Carbon fibers, owing to their excellent properties such as low density, high stiffness, good resistance toward chemical and environmental effects, and ability to withstand high temperature, find an important place in high-tech areas. with lightweight matrices. They have shown good potential for use as reinforcing agents in light metals such as aluminum and magnesium [1 – 3]. Although carbon fiber composites were initially developed for the aerospace industry and defense applications [4 – 9], the scope of their applications is widening to include areas such as ship and submarine structures [1 0, 11], nuclear technology [121], electrical and electronic applications [13 – 16], mining [17], medical [18–21], sporting goods [22], automobiles [18], etc. The growing demand for carbon fibers in 1987 and projections for the future can be seen from the estimates given in Table 1. They are used in composites The table shows a twofold increase in European demand for carbon fibers by 1995.

Acrylic Precursors for Carbon Fibers

Acrylonitrile (AN) was copolymerized with acrylic acid (AA), methacrylic acid (MAA), and itaconic acid (IA) by the aqueous suspension method at 40°C with ammonium persulfate and sodium metabisulfite as the redox initiator. The reactivity ratios for the AN–AA and AN–IA systems were also calculated by the Finemann–Ross and the Kelen–Tudos methods. Higher r2 (AA) for the AN–AA system in comparison to r2 (IA) for the AN–IA system indicates greater reactivity of AA toward the propagating species. The influence of co-monomers on intrinsic viscosity, tacticity, and number-average sequence lengths was studied. 13C-NMR spectra revealed that AN copolymers having approximately 2 mol % of AA have a greater percentage (>30%) of isotactic content than of homopolyacrylonitrile. Tacticity has also been calculated from infrared spectra of the polymers using stereospecific absorption bands at 1250 and 1230 cm−1. © 1993 John Wiley & Sons, Inc.

Acrylonitrile-acrylic acids copolymers. I: Synthesis and characterization

Solution copolymerization of acrylonitrile (AN) with various vinyl acids, i.e., acrylic acid (AA), methacrylic acid (MAA), and itaconic acid (IA), was carried out in DMF at 70°C using α,α′-azobisisobutyronitrile (AIBN) as an initiator with an acidic monomer of 0.012–0.092 mol %. Copolymers were characterized by FTIR, CHN analysis, 1H-and 13C-NMR, and viscometry. The reactivity ratios were calculated using Fineman–Ross and Kelen–Tudos methods. In all three systems, the value of r1 (AN) is much less than the value of r2. However, the r2 (MAA) is higher than r2 of (AA) and (IA). The reactivity ratios were calculated using Q and e schemes also. The results are in good agreement with experimentally calcualted data. The tacticity and sequence length distribution of these copolymers were calculated using 13C-NMR from CN and CH signals. It was observed that the isotacticity of acrylonitrile–itaconic acid copolymer P(AN–IA) with 8.2 mol % of a comonomer is lower than that of P(AN–MAA) with 10.3 mol % and P(AN–AA) with 7.61 mol %. © 1996 John Wiley & Sons, Inc.

P. Bajaj

Papers

Fire-retardant materials

Finishing of textile materials

Acrylic Precursors for Carbon Fibers

Acrylonitrile-acrylic acids copolymers. I: Synthesis and characterization

Solution polymerization of acrylonitrile with vinyl acids in dimethylformamide