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We successfully employed bisphenol A and several different formyl-containing monomers as useful building blocks to construct a series of hydroxy-group-containing porous organic polymers in a sealed tube at high temperature. Fourier transform infrared and solid-state 13C CP/MAS NMR spectroscopy are utilized to characterize the possible structure of the obtained polymers. The highest Brunauer–Emmet–Teller specific surface area of the phenolic-resin porous organic polymers (PPOPs) is estimated to be 920 m2 g–1. The PPOPs exhibit a highest carbon dioxide uptake (up to 15.0 wt % (273 K) and 8.8 wt % (298 K) at 1.0 bar), and possess moderate hydrogen storage capacities ranging from 1.28 to 1.04 wt % (77 K) at 1.0 bar. Moreover, the highest uptake of methane for the PPOPs is measured as 4.3 wt % (273 K) at 1.0 bar.

Two variants of poly(dimethylsiloxane-co-methylhydrosiloxane) polymers were functionalized with three different phenol derivatives (3-pentadecylphenol, 4-tert-octylphenol and phenol) to synthesize six new phenoxylated siloxane polymers using the Piers−Rubinsztajn process/chemistry. The new polymers ranged in physical appearance from waxy solids to liquids. It has been shown that the different phenoxy fragments directly influence the physical and thermal properties of the polymers in a predictable and rational way. The variant based on 3-pentadecylphenol is of particular interest as it utilizes a naturally sourced and sustainable material from cashew nut shell oil. © 2017 Society of Chemical Industry

This Concept examines strategies to design advanced polymers with high CO2 permeability and high CO2 /N2 selectivity, which are the key to the success of membrane technology for CO2 capture from fossil fuel-fired power plants. Specifically, polymers with enhanced CO2 solubility and thus CO2 /N2 selectivity are designed by incorporating CO2 -philic groups in polymers such as poly(ethylene oxide)-containing polymers and poly(ionic liquids); polymers with enhanced CO2 diffusivity and thus CO2 permeability are designed with contorted rigid polymer chains to obtain high free volume, such as polymers with intrinsic microporosity and thermally rearranged polymers. The underlying rationales for materials design are discussed and polymers with promising CO2 /N2 separation properties for CO2 capture from flue gas are highlighted.

Self-healing polymers and composites utilizing the Diels–Alder reaction have received considerable attention due to the intrinsic healing capability of this crosslink. However past research focused on chemistries that cleave at low temperatures, which places limitations on the polymer's use temperature. Here, it is demonstrated that the crosslinking Diels–Alder (DA) reaction between anthracene and maleimide moieties can be used to achieve healing efficiencies greater than 94% for polymers and 69% for carbon fiber reinforced polymer composites while remaining stable beyond 240 °C. It is shown that the self-healing behavior can be obtained purely through the reformation of mechanically cleaved DA adducts since the cleaving temperature is beyond the decomposition temperature. The self-healing polymer reported here is obtained from liquid monomers allowing the polymerization of bulk polymer samples and its infusion into continuous fiber reinforced composites. It is shown that the polymer can yield thermally stable composites with mechanical properties comparable to those of other engineering polymers and structural composites.

Unsaturated polyester resins (UPRs) are most commonly used coating materials on steel among thermosetting polymers because of their low cost, easy application and good performance properties. However, UPRs show insufficient fire-resistance in respect of relatively high flammability accompanied by smoke production upon burning due to aromatic groups in the structure. Consequently, improving the fire retardancy of UPRs for extending their application becomes pivotal. Fire retardants (FRs) are widely used in polymers because they prolong the time to ignition, slow down the rate of flame spread, and generate less heat and smoke or toxic fume compared with the unmodified polymers. It has been a challenge to develop a cost effective, environmentally friendly fire retardant system which minimizes the negative effect on performance properties of the polymers [1 - 4].

International audience; Environmental concerns arising from the limits to the waste management of plastics have entailed a strong development of biobased and biodegradable polymers for a wide range of applications. Tailoring new plastics and composites within a perspective of sustainable development aims to create an environmentally safe alternative to oil based polymer materials. Different categories of these polymers can be distinguished according to their complete or only partial renewable character as well as their ability to biodegrade.

Developing a high efficient, environmental-friendly and universal fire-safe strategy for combustible polymers is crucial but challengeable. Inspired by nacre, we developed a super-efficiently fire-safe nanocoating based on carboxymethyl chitosan (CCS) and modified montmorillonite (MMT) via one-step self-assembly. The nanocoating possessed well-arranged nacre-like hierarchical microstructure, exhibiting high transparency and specific nacre-like iridescence. More importantly, the nanocoating endowed many large-scale polymer substrates, such as polyester film, cotton fabric and polyurethane foam, with super-efficient fire-safety by dip-coating or spray-coating. All the coated substrates were self-extinguished in the burning tests. Meanwhile, their heat release and smoke production were decreased remarkably. Most notably, the peak heat release rate, total heat release, peak smoke production rate and total smoke production of polyurethane foam were decreased by 84.1%, 89.4%, 84.4% and 95.2%, respectively. Additionally, no organic solvent, halogen and phosphorus element were involved, which was environmental-friendly. Our findings provide a super-efficient, economical, universal and green fabrication strategy for fire-safe polymers.

Ionic liquid monomers substituted with a polymerizable group were polymerized using free radical polymerization and group transfer polymerization mechanisms. Homopolymers containing a polycation or a polyanion structure were made as well as various copolymers. The latter include statistical copolymers, alternating copolymers, and block copolymers. The new polymers obtained may become of interest for application as binders for coatings. Furthermore, glass transition temperature of the polymers obtained was discussed as an important parameter for the application temperature needed for film formation. It was shown that a variation of the ionic liquid monomer structure affects the glass transition temperature of the polymer obtained. Moreover, antimicrobial properties of selected polymers were investigated using Escherichia coli and Micrococcus luteus. The results show significant differences in the antimicrobial properties of the polymers investigated. This is highly interesting for applications in which these polymers function as binders in coatings.

This paper is an overview of the versatile polymer materials containing different functional groups at the main or side chain to remove hazardous inorganic species. These materials include water-insoluble, nanocomposite and water-soluble polymers. Water-insoluble polymers and nanocomposites are used in adsorption and ion exchange processes, whereas water-soluble polymers are employed with ultrafiltration membranes in the liquid-phase polymer-based retention technique. © 2015 Society of Chemical Industry

Data on the history of preparation of 5,5-dimethylhydantoin—a compound with nitrogen-containing cycles—as a monomer for preparation of oligomers and epoxy polymers have been reported. The possibility and conditions for preparation of oligomers containing dimethylhydantoin (DMHD) fragments has been considered, and their characteristics have been presented. Epoxy polymers have been prepared during hardening of hydantoin-containing oligomers by anhydride and ammine hardeners. Indicators of cohesive and adhesive strength of such polymers, their heat resistance, and water absorption have been determined. One variant of application of the obtained polymers—impregnating a structure for concrete coverings—has been discussed.

To address the need for perfluoro polymers with higher Tg, we have prepared and characterized various perfluorodioxolane monomers via direct fluorination of the hydrocarbon precursors. These monomers were readily polymerized in bulk or in solution initiated by perfluorodibenzoyl peroxide. The polymers obtained have relatively high Tg(~160°C) and exhibited low material dispersion. These polymers are completely amorphous and soluble in fluorinated solvents. The polymers are also chemically and thermally stable (Tg > 300°C). Thus, these perfluorodioxolane polymers may be used as plastic optical fiber material where high Tg is required, such as in automobile and aircraft application. These perfluorodioxolane polymers were also investigated for use as gas separation membrane. Among these polymers, the copolymer of perfluoro (2-methylene-1,3-dioxolane) and perfluoro (2-methylene-4,5-dimethyl dioxolane) showed superior gas separation performance compared with the commercial perfluoro polymers for a number of gas pair, including CO2/CH4, He/CH4, H2/CH4, and N2/CH4. Copyright © 2015 John Wiley & Sons, Ltd.

The influence of the structure of adamantane-containing epoxy polymers (EP) on their resistance to thermal, chemical, and biological aging under conditions of the action of aqueous solutions of the carboxylic acids, which are known as metabolites of the vital activity of mold fungi, is studied. It is established that the adamantane-containing EP show higher heat resistance and thermal stability than do epoxy amine polymers based on aliphatic diamines, providing high adhesive strength up to temperatures ranging from 150 to 200°C. It is shown that incorporation of the adamantane fragments into the structure of a hardening agent increases the resistance of the epoxy polymers to aggressive media (water, alkalis, acids, and solvents), including metabolites of mold fungi.

The chemical or electrochemical oxidation of phenylenediamines in acidic aqueous media yields the corresponding oligomers or polymers. Their structures and properties are discussed in relation to a closely-related conducting polymer, polyaniline. Depending on the reaction conditions, polyphenylenediamines are produced as powders, colloidal dispersions, thin films, or composites. In contrast to polyaniline, polyphenylenediamines are rated as non-conductors and their conductivities are low. Similarly to polyaniline, these polymers display a salt–base transition and they are redox-active. They act as reductants of noble-metal compounds to the corresponding metals or as precursors in the carbonization to nitrogen-rich carbons. Applications proposed in the literature are outlined; they include the corrosion protection of metals, catalysis, electrorheology, sensors, energy-conversion devices, electrochromism, noble-metal recovery, and water treatment.

This chapter reviews recent studies on blends of conventional cellulose esters (CEs), such as cellulose acetate (CA), cellulose propionate (CP), and cellulose butyrate (CB), with non-crystalline vinyl (co)polymers mainly comprising the N-vinyl pyrrolidone (VP) unit. The mixing behavior of the CE/VP-containing copolymer blends is seriously affected by the chain length (i.e., carbon number) and degree of substitution (DS) as to the acyl substituent of the CE component, and by the VP fraction in the copolymer component. Relatively low-substituted CEs are commonly miscible with VP-containing copolymers by virtue of hydrogen bond formation between the CE-hydroxyls and VP-carbonyls. The blend systems using CP and CB with higher DSs impart a “miscibility window” involved in the monomer composition that constitutes the copolymer component. This observation is interpretable as a result of the indirect CE–copolymer attraction driven by intra-copolymer repulsion. A convincing argument for the miscibility behavior is provided by assessing the attractive or repulsive interactions between the blend constituents in terms of the viscometric interaction parameter. In addition to the basic characterization of the blend miscibility and intermolecular interaction, we also survey some useful applications of miscible CE blends to functional films exhibiting improved adsorption, optical, or thermomechanical properties. Particular attention is paid to the molecular orientation and optical anisotropy induced in deformed films of CA/VP-methyl methacrylate polymer blends.

International audience; In the last few years, polymer materials scientists have put a lot of effort into the design of poly mer-based materials, tailored from the nanometer scale via the introduction of block copolymers, ionomers, or inorganic-rich nano-objects in order to introduce functionalities such as mechanical reinforcement, gas barrier properties, fire retardancy, etc. In the last decade, ionic liquids (ILs) have moved from relative obscurity to something that most chemists are now very aware of. At present, the interest in ILs shows a continuous increase and they are being examined as new components within polymer-based materials for a wide range of applications of advanced materials. The unique set of physico-chemical properties of ILs finely tuned from their chemical structure makes them suitable in numerous applications in polymer science. ILs can be investigated as additives in the design of polymer materials, as novel electrolytes in batteries, as structuration agents of polymer matrices, and as processing aids, plasticizers, and surfactants in the preparation of functional polymers.

Polymer materials flammability represents a major limitation to their use and hence to the development of most polymer-based advanced technologies. Environmental and safety concerns are leading to progressive phasing out of versatile and effective halogen-based fire retardants which, so far, ensured a satisfactory polymer fire hazard control. Among the intensive efforts which are being made to develop new, environmentally safe, polymer fire protection approaches, the recognition of the paramount role played by the polymer surface during combustion and the exploitation of the new nanotechnologies developed for polymer surface engineering offer a promising perspective for polymer fire retardance. Indeed, heat transfer to the polymer and diffusion to the gas phase of polymer degradation combustible volatiles, which both fuel the combustion, occur across the polymer surface which characteristics regulate the polymer combustion process. It is shown that by engineering the polymer material surface by intumescent coatings or layer by layer nano-deposition or by oxidic nanostructures sol–gel synthesis, polymer combustion can be conveniently slowed down to extinguishment, complying fire safety rules of specific applications, through the creation of a surface barrier to heat and mass transfer across the polymer surface.

The easy accessibility and high adjustability of polymers mainly accounts for the great impact of such materials on modern society. Besides this great success, an important matter is the accumulation of large amounts of end-of-life polymers, which are mainly deposited in landfills or converted by thermal recycling or down-cycling to low-quality materials. In contrast to that, the depolymerization of end-of-life polymers to monomers, which can be applied as feedstock in polymerization chemistry for high-quality polymers, is only carried out for a small fraction of waste. Polysiloxanes are extensively used in a diverse array of technological applications. Based on intrinsic properties of polymers, depolymerization is challenging and only a few high-temperature or less environment-friendly processes have been reported. In this regard, we have set up a capable low-temperature protocol for the depolymerization of poly(dimethylsiloxane) in the presence of catalytic amounts of simple iron salts in combination with different depolymerization reagents. The application of benzoyl fluoride, benzoyl chloride/potassium fluoride, or benzoic anhydride/potassium fluoride as depolymerization reagents affords difluorodimethylsilane or 1,3-difluoro-1,1,3,3-tetramethyldisilxanes as products, which are interesting building blocks for the synthesis of new polymers and allow an overall recycling of polysiloxanes.

Novel biocidal organic N-halamines (based on imidazoline dione rings) were used as a substituents for poly(p-methyl styrene). The biocidal polymers and substituents have been investigated using thermogravimetric analysis. The thermal resistance of investigated compounds was compared to those of non-halogenated precursors. The introduction of chlorine atoms to polymers decreases their thermal resistance comparing to precursors but efficient stabilization is possible by using octyl tin mercaptide. The complex mechanism of thermal decomposition of polymers has been discussed.

The effect of small additives of functionalized multiwall carbon nanotubes used as a modifier on the formation and properties of epoxy polymers cured with diaminodiphenyl sulfone is investigated. In the range of additive concentrations 0.01–0.50 wt %, there are extreme dependences of dynamic storage modulus and the glass-transition temperature on modifier concentration. As shown by electron microscopy and X-ray scattering, regions with increased packing densities of macromolecules are formed in the polymers in the presence of the modifier. The effect of the specific surface on the kinetics of curing of epoxy resins is observed. A mechanism controlling the formation of the epoxy matrix that is responsible for the inhomogeneous polymer structuring that defines the final properties of the polymers is suggested.

Hybrid nanocomposites are obtained by photo-initiated copolymerization of N-vinylpyrrolidone (or acrylic acid) with 3-(trimethoxysilyl)propyl methacrylate, grafted on an Aerosil surface, followed by immobilization of silver nanoparticles. The materials obtained are particles (aggregates) of size 12-17 μm, consisting of silica nanoparticles bonded by a polymer layer in which aggregated silver particles about 17 nm in size are found. The presence of silver nanoparticles in the composites increases their thermal stability.

Currently, a lot of research efforts have been directed toward exploiting the special high-performance characteristics of polymers with sulfur in the backbone. Sulfur-containing polymers fall under various classes and cover an extremely broad property range. The impetus to their development resulted from the unique properties and success in their applications, depending upon the type of linkage introduced. This review basically sets out to explain the design, synthesis, properties, and applications of various sulfur-containing polymers especially polyamides, polyimides, poly(amide-imide)s, polybenzimidazoles, polyurethanes, polyesters, etc. Outstanding performance of these polymers came up from their structures having sulfur-based groups such as thiophene, sulfide, sulfone, thiazol, and thiourea. Thus these linkages endow special features to such functional polymers. The sulfur-containing polymers are also described here with reference to their relevance as optically active, liquid crystalline, flame reta...

Three novel kinds of linear silicon-containing hybrid polymers with Si−C≡C units were synthesized by polycondensation reactions using the Grignard reagent method. All the polymers were thermosetting, highly heat-resistant, moldable and easily soluble in common organic solvents. The structure, curing behavior, thermal and oxidative properties were characterized using Fourier transform infrared spectroscopy, 1H NMR, 13C NMR, gel permeation chromatography, differential scanning calorimetry and thermogravimetric analysis. The results obtained can provide theoretical guidance for determining the curing of the resin system. In addition, the cured polymers exhibit excellent thermal and oxidative stabilities with temperatures of 5% weight loss (Td5) above 480 °C and 450 °C in nitrogen and air respectively; the residues at 1000 °C were above 70.0% and 45.0% respectively. The thermal and oxidative stabilities of the polymers are attributed to a crosslinking reaction between the Si−H and C≡C bonds or C≡C bonds. These polymers have the potential for use as high-temperature-resistant resins and ceramic precursors. © 2013 Society of Chemical Industry

Polymerization of Phosphorus-Containing (Meth)acrylate Monomers Polymerization of Phosphorus-Containing (Meth)acrylamide Monomers Phosphorus-Containing Both Vinyl or Allyl Monomers Synthesis and Polymerization of Vinyl Phosphonic Acid 2-Methacryloyloxyethyl PhosphorylCholine (MPC) Polymers Polyphosphoesters Polyphosphazenes High Polymers Phosphorus-Based Monomers Used for Dental Application Biomedical Applications of Phosphorous-Containing Polymers Complexation with Metals: Anti-Corrosion The Use of Phosphorus-Containing Polymers for the Removal of Metal Ions from Wastewaters Flame Retardancy of Phosphorus-Containing Polymers Proton Conducting Phosphonated Polymers and Membranes for Fuel Cells

The molecular design concept of silicon-nitrogen synergistic effect for highly-efficient flame retardants has been demonstrated in the preparation of reactive type flame retardants which exhibits high flame retardation efficiency and property enhancement ability for developments of high performance polymers. In the synthetic route, a benzoxazine-containing triethoxysilane compound is obtained and used as a monomer together with diphenylsilanediol to result in branched benzoxazine-containing polysiloxanes (PBz-PSO) through a 3 + 2 condensation polymerization reaction. The chemical structures and properties of Bz-TES and PBz-PSO compounds have been characterized with Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and differential scanning calorimetry. PBz-PSO samples are reactive polymers as they possess thermally-reactive benzoxazine groups. Thermally-crosslinking the PBz-PSO samples results in silicon-containing polymers which show high thermal stability and high flame retardancy (limited oxygen index > 45). Addition of 5 wt% PBz-PSO to a conventional benzoxazine resin could simultaneously improve its flame retardancy (passing the UL 94-V0 test) and increase its glass transition temperature from 145 °C to 205 °C. PBz-PSO samples are highly-efficient reactive-type flame retardants for preparation of halogen-free and phosphorus-free polymers.

To develop ionic-conductive film-shaped electrolytes with high reliability, we designed and synthesized the following networked polymers with an epoxy/amine curing system using poly(ethylene glycol) as the main skeleton, and examined their fundamental properties such as ionic conductivity, thermal stability, and inflammability. (1) Networked polymers having quaternary ammonium salt structures. (2) Networked polymers having lithium sulfonate salt structures. (3) Networked polymers having lithium sulfonylimide salt structures. (4) Networked polymers swollen with ionic liquid solutions of lithium salts. Consequently, we found that networked polymers swollen with ionic liquid solutions containing lithium salts showed high ionic conductivity and high thermal stability with excellent non-flammability.

Results are presented of investigations devoted to the creation of polymer compositions using oligomeric urethane-siloxane rubbers as basic polymers (foreign analogs are STO, SPUR or STP polymers). The sealants developed based on these binding materials exhibit a wide range of rates of curing, good physicomechanical characteristics, and high adhesion to various substrates. The corresponding low-, medium-, and high-modulus polymer compositions may find wide application in automobile and transport engineering, shipbuilding, the construction industry, and other fields.

A new set of polymers, which could act as flame retardant additives by blending with “commodity” polymers, was synthesized by chemically modifying poly(vinyl alcohol) (PVA) through reaction with a phosphorous-containing reagent. The phosphorous-based moiety introduced was 1-oxo-2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane, which has been reported to be a good flame retardancy promoter structure. For a larger application and better compatibility with thermoplastic polymers, we also introduced in the polymeric additives aliphatic (valeroyl group) or aromatic (benzoyl group) moieties. The structures and properties of the polymers obtained were studied by 1 H, 13 C and 31 P NMR, infrared spectroscopy (FTIR–ATR), inherent viscosity, inductively coupled plasma-atomic emission spectrometry (ICP–AES), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). A detailed study of their thermal degradation was performed by thermogravimetry coupled with mass spectrometry (TG–MS) and pyrolysis. Their thermal behavior and high char yield at high temperatures make them promising candidates to act as flame retardant additives through the formation of protective barriers.

Fluorine-containing polyorganophosphazenes, (NPRF2)n, constitute one of the largest and best developed areas of inorganic–organic polymer chemistry. Linear high polymers in this class are fire resistant, hydrophobic, fiber-, film- and elastomer-forming materials that, in many cases, have property combinations that cannot be matched by conventional fluorocarbon or non-fluorinated polymers. Most macromolecules of this type are synthesized by using the alkali metal salts of fluoroalcohols or fluorophenols for chlorine-replacement reactions with poly(dichlorophosphazene). This approach allows the synthesis of polymers with only one type of fluorinated side-group, mixed-substituent polymers or block copolymers. Single-substituent polymers in this series generate either semicrystalline or amorphous materials, depending on the length and flexibility of the side-chains. Mixed-substituent polymers are usually amorphous materials that can be covalently crosslinked to generate elastomers. In addition, elastomers have been produced by the incorporation of small percentages of rigid bulky side-groups that favor side-chain interdigitation, a process that leads to physical crosslinking. Finally, fluorophosphazene elastomers are accessible by the incorporation of organosilicon side-groups and by the formation of polyphosphazene–polyorganosilicon block copolymers.

Lignin is the most abundant phenolic polymer on the planet. Its utilization for non-fuel sources, mostly water-soluble surfactants and components of network polymers and thermoplastic polyblends is reviewed. Limiting solubility and thermal deformability properties are addressed by molecular fractionation and/or chemical modification. Simple ester and ether derivatives are beginning to attract commercial interest in markets for materials with a basis of sustainable biopolymers.

Typical high temperature (HT) stable polymers might be similar in thermal and mechanical performance but lack cost effective thermoplastic processing via injection molding or extrusion. This article concentrates mainly on HT thermoplastic polymers, their basic properties and some applications. Chemical structures and common trade names are given, the incorporation of links such as oxygen, keto, and sulfone groups increases proccessability while maintaining acceptable temperature stability. One possible definition includes materials which allow thermoplastic processing; possess a continuous service temperature (CST) above 150 °C; are chemical and radiation resistant; and exhibit a low flammability or are even self-extinguishing.

Plastic is a generic term for an extremely large and complex family of materials that are generally polymeric molecules; that is, they are comprised of relatively simple monomer species that build up into a linear, branched, or three-dimensional network macromolecule. There are numerous types of plastic and base polymers from which they are made. This article discusses, briefly, some common types of plastic and their properties, with some emphasis on the nature and consequence of polymer degradation.

Most of unwanted fires are fuelled by polymeric materials, ranging from natural polymers found in wood, cotton or wool, to synthetic polymers (“plastics”) derived from crude oil, showing much greater flammability. Polymer molecules are too large to be volatile, but break down thermally, by chain scission and chain stripping, to release fuel to the vapour phase prior to ignition. Experimental and numerical methods for investigating polymer decomposition are reviewed, followed by a description of the chemical decomposition of individual polymers. In order to use flammable synthetic polymers in high risk applications, fire retardants are frequently added to meet regulatory requirements. The range of available fire retardants is described in relation to their different modes of action. This is followed by a description of the more common test methods used to assess the flammability of polymeric materials, including ignitability, flame spread and heat release rate, together with a summary of the importance of physical properties and char formation on their burning behaviour.

Thermal treatment of highly stable porous organic polymers based upon the Yamamoto polymerization of 2,2′,7,7′-tetrabromo-9,9′-spirobifluorene was done. The polymers are shown to be thermally and chemically stable. Upon thermal treatment the polymers are shown to have BET surface areas of ca. 2,000 m2/g and 2,500 m2/g respectively.

Microporous polymers based on 1,3,5-triazine units are prepared by Friedel-Crafts reaction of 2,4,6-trichloro-1,3,5-triazine with aromatic compounds. 2,4,6-Trichloro-1,3,5-triazine is polymerized with benzene, biphenyl, and terphenyl in dichloromethane in the presence of aluminum chloride. The surface areas of the polymers are in the range of 558 to 1266 m2 g−1, depending on the aromatic linker length. At ambient pressure and temperature, the polymers exhibit high CO2 uptakes of 38–51 cm3 g−1. The CO2 uptake is significantly enhanced by 70–90% for the polymers carbonized at 400 °C for 1 h and at 800 °C for an additional 1 h under nitrogen. This result suggests that rigid microporous polymers can be used as precursor polymers for the synthesis of advanced porous carbon materials without the activation process.

In an effort to minimize uncertainties seen in bench scale tests, the sources of variability in fire test data are investigated. An earlier study on poly(aryl ether ether ketone) (PEEK) has showed that the fire performance parameters of this thermoplastic change noticeably when exposed to moisture prior to test. The present research is a follow-up study where a series of cone calorimetry tests are conducted on conditioned PEEK specimens to analyze the previously reported ignition time scatter and its relation to surface bubble formation. Pyrolysis modeling is, subsequently, carried out, to relate the moisture content with the model parameters and to explain the possible physical mechanisms that cause the difference in ignition times between wet and dry samples.

Crosslinking of polymers using crosslinking agents has been widely utilized to further improve the mechanical and thermal properties of the polymers. We have explored various aliphatic and aromatic dicarboxylic acids such as malonic acid, glutaric acid, isophthalic acid, terephthalic acid and terephthaloyl chloride as crosslinking agents to crosslink polydimethylsiloxane copolymer [poly{poly(dimethylsiloxane-1000)-propylamine-5-aminoisophthaloyl}] to improve its flame retardant properties. We have also used nanoclays [Cloisite 20A, 2C18 MMT (dimethylditallowammonium-/ dimethyldioctadecylammonium-modified montmorillonite)] along with the crosslinker during crosslinking process to further reduce the flammability of the crosslinked polymers. Among all the crosslinkers investigated, isophthalic acid with the nanoclay was found to have the best performance for flame retardant applications. The present work provides a basis to further improve the performance of silicone-based polymers for the flame retardant ap...

Carbon-based, non-precious-metal catalysts for the oxygen reduction reaction were prepared from polyimides, polyamides, and azoles, by pyrolysis at 900ºC under flowing N2. The catalytic activity for electrochemical oxygen reduction was evaluated by the onset potential, measured at a current density of -2 μA cm-2. Pyrolyzed polymers with high N content showed higher onset potentials. In particular, one catalyst derived from azole (Az5) had an onset potential of 0.82 V, despite being prepared without the use of any metals. Additionally, a catalyst prepared by multistep pyrolysis of polyamide mixed with FeCl2 had high N content and high oxygen reduction activity, with an onset potential of 0.95 V. A membrane electrode assembly prepared using this catalyst had an open circuit voltage of 0.99 V, and a maximum output of 0.48 W cm-2.

With the rapid development of nanotechnologies and nanomaterials since 1990s, the studies on polymer-based nanocomposites have been extensively focused on their properties’ enhancement. Among these, it is well known that nanoparticles can also enhance thermal degradation of nanocomposites. This review is focused on highlighting the effect of different nanoparticles, their dispersion and the used modifiers, on polymer thermal stability. The whole range of polycondensation polymer matrices is covered. Most of these polymers have reactive end groups which can interact with inorganic nanoparticles surface. Hydrogen or covalent bonds can be formed, which can increase the adhesion of nanoparticles with the polymer matrix, resulting in higher dispersion degrees. This, in most cases, leads to substantial enhancement of thermal decomposition properties. Only in nanocomposites containing montmorillonite there are conflicting results and accelerating degradation was also reported. Organoclays also have similar effects on polymers thermal stability and in this case the achieved clay dispersion (intercalated-exfoliated), as well as the used modifier, can alter the thermal decomposition of polymers. The used amount of nanoparticles plays an important role on the thermal stability of nanocomposites. In most cases thermal stability enhancement takes place at low loading (4–5 wt%) of nanoparticles, while at higher contents thermal stabilization becomes progressively smaller.

WOS:000268898300082 The preparation of new poly(urethane-imide)s (PUIs) having acceptable thermal stability and higher flame resistance was aimed. Two new aromatic diisocyanate-containing methyldiphenylphosphine oxide and triphenylphosphine oxide moieties were synthesized via Curtius rearrangement in situ and polymerized by various prepared diols. Four aliphatic hydroxy terminated aromatic based diols were synthesized by the reaction between ethylene carbonate and various diphenolic Substances. Chemical structures of monomers and polymers were characterized by FTIR, (1)H NMR, (13)C NMR, and (31)P NMR spectroscopy. Thermal stabilities and decomposition behaviors of the PUIs were tested by DSC and TGA. Thermal measurements indicate that the polymers have high thermal stability and produce high char. Polymers exhibit quite high fire resistance, evaluated by fire test UL-94. The films of the polymers were prepared by casting the solution. Inherent viscosities, solubilities, and water absorbtion behaviors of the polymers were reported in. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 114:1329-1338, 2009

Butadiene-rubber toughened styrene polymers, such as acrylonitrile-butadiene-styrene (ABS) copolymer and high impact polystyrene (HIPS), are noncharring polymers. They are generally blended with polycarbonate (PC) or polyphenyleneether (PPE), which are char forming polymers, to improve char forming ability for styrenic blends containing conventional phosphate flame retardants. To achieve cost effective flame retardant system, PET was selected as a potential char-source for ABS blends through the thermogravimetric analysis (TGA) and chemical structure analysis of various polymers. PET may contribute to the enhancement of flame retardancy of ABS/PET blends, especially in the presence of small amounts of phenol novolac (PN). The effective flame retardancy of this system is believed to be accomplished through the enhancement of interchain reactions by PN. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

An overview of the effects of different nanoscale materials on the flammability of two thermoset polymers is presented and discussed in this paper. Its goal is to bring together our recent experimental results obtained for different material systems of nanoclays, nano-magnesium hydroxide (nano-Mg(OH)2) and carbon nanotubes (CNT) in epoxy and unsaturated polyester resins; some of these results have already been published elsewhere. It is shown that these nanoparticles can be used to lower the heat release rate (HRR) of the polymers when exposed to a fire situation. On the other hand, in the majority of the cases this low flammability of polymer nanocomposites is only achieved in terms of HRR, but fails in terms of time-to-ignition or the extent of smoke released.

Styrene was radically copolymerized with a spiro-orthoester with an acrylate group (SOE-AC), and terpolymerized with SOE-AC and diethyl(methacryloyloxymethyl)phosphonate (DEMMP). This was done for several different feed ratios, to obtain polymers with spiro-orthoester moieties in the side chain. These polymers were then crosslinked with ytterbium triflate, as cationic initiator, via the double ring-opening polymerization. The thermal stability and fire retardant properties of these materials were evaluated by TGA and LOI. The DEMMP-containing polymers give materials which were significantly more flame retardant than the nonphosphorus-containing materials, as indicated by the LOI measurements. The volume changes measured upon crosslinking of the polymers were evaluated by density measurements with a gas pycnometer. In all the cases, expansion was observed. This indicates that SOE-AC is an effective monomer for crosslinkable polymers without volume changes.