Polystyrene thermo-oxidation

Fichera MA, Braun U, Schartel B, Sturm H, Knoll U, Jager C, Solid-state NMR investigations of the pyrolysis and thermo-oxidative decomposition products of a polystyrene/red phosphorus/magnesium hydroxide system. J. Anal. Appl. Pyrolysis 2007 78 378-386. 

LPD deposition of ceramic thin films is a potentially general approach to improving the abrasion resistance and thermo-oxidative stability of polymers. Dutschke et al.14,15 have deposited titania on variously treated polystyrene (PS). Continuous, adherent anatase films form on PS either after hydroxylation in... 

In an unpubhshed study, SPME and a 65p,m PDMS/DVB fiber were apphed for extraction of polystyrene (PS) thermo-oxidation products. As seen in Fig. 4, styrene monomer was the main compoimd migrating from the virgin material after low temperatme thermo-oxidation at 80 °C. After 20 weeks, new low molecular weight compoimds including toluene, ethyl benzene, benzaldehyde and acetophenone were also identified. Volatiles migrating from poly(vinyl chloride)/polycaprolactone-carbonate (PVC/PCL-PC) during thermo-oxidation were extracted by PDMS/DVB fiber [19]. The identified compounds included degradation products of PCL-PC, i.e.,... 

Fig. 4 Compounds migrating from low temperature thermo-oxidized polystyrene extracted by SPME after a 0 weeks, b 5 weeks and c 20 weeks at 80 °C. The most abundant peak in the chromatograms is styrene monomer...

Polystyrene-based resins have been used widely as supports for metal complex catalysts and other reactive species. These polymers, however, have a drawback in their limited thermo-oxidative stability [1,2]. The scope for application is therefore restricted, particularly in polymer-supported transition metal complex oxidation catalysts [3]. Consequently there is a need for the development of polymer supports with a much higher intrinsic thermo-oxidative stability. Polybenzimidazoles and polyimides are likely candidates in this respect. 

Ismail H, Mohamad Z, Bakar AA (2003) A comparative study of processing, mechanical properties, thermo-oxidative aging, water adsorption, and morphology of rice husk powdCT and silica fillers in polystyrene/styrene butadiene rubber blends. PolymCT Plast Tech Eng 42 (1) 81-103... 

Because the thermal stability of polystyrenes and polymethacrylates is limited to 200°C, continuous use of a polymer-supported reactive species tends to be limited to significantly lower temperatures than this (see polymeric sulphonic acids). There is considerable interest in supporting, in particular, alkene oxidation catalysts on polymers and to operate reactions at temperatures above 200°C. To achieve this, novel thermo-oxidatively stable supports are required and some progress has been made in this direction. More details of specific applications will be given later, but supports based on, for example, polyacrylonitrile [50-52], polyamides [53-56], polysulphone [57, 58], polyaniline [59] and polybenzimidazole... 

K. Chen and S. Vyazovkin, Mechanistic differences in degradation of polystyrene and polystyrene-clay nanocomposite Thermal and thermo-oxidative degradation. Macro-molecular Chemistry and Physics, 207 (2006), 587-95. 

B. B. Troitskii, L. S. Troitskaja, A. A. Dmitriev, and A. S. Yakhnov, Inhibition of thermo-oxidative degradation of poly(methyl methacrylate) and polystyrene by Ceo-European Polymer Journal, 36 (2000), 1073-84. 

A significant problem associated with the conventional polystyrene supports is the low mechanical strength and often poor thermo-oxidative stability. Degni and CO workers developed the facile anchoring method of chiral TADDOL on... 

TVA-FTIR allows method development for online detection and quantification of degradation products, as they are formed in the TVA experiment. Stevenson et al [944] have used TVA and SATVA as a platform for spectroscopic investigations of polymer degradation processes, as in case of PMMA and poly(bisphenol A, 2-hydroxypropylether). The kinetics of thermal and thermo-oxidative degradation and characterisation of the various degradation products of polystyrene alone and in the presence [949] of the flame retardant IDBP were investigated using TVA, FTIR and GC-MS. Other applications of TVA in problems in polymer chemistry have been reported [943,952]. The method is now near defunct. 

Figure 2. Calculated curves according to Equation (11) and experimental points for initial stages of hydroperoxide formation during thermo-oxidative degradation of isotactic polystyrene. ...

In works [46-48] by method of EPR-tomography thermo- and photo-oxidation of poly(acrylonitrile-butadiene)styrene (ABS) copolymer were studied. This polymer is structurally and dynamically micro-heterogeneous, i.e. there are regions with high content of polybutadiene and regions with high content of polystyrene or polyacrylonitrile. In polymer... 

The main aim of this work was the generation of novel smart materials, in this case thermo-responsive inorganic/organic meso/nanostructured hybrids based on different low molecular weight liquid crystals (LC) and conductive rutile Ti02 nanoparticles. LC as partially miscible with polystyrene (PS) was well-dispersed using amphiphilic poly(styrene-i-ethylene oxide) block copolymers (PS-b-PEO). Simultaneously, LC was used as surfactant for conductive rutile Ti02 nanoparticles. 

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