Poly copolymers, thermal characteristics

Hazer B (1996) Poly(P-hydroxynonanoate) and polystyrene or poly(methylmethacrylate) graft copolymers microstructure characteristics and mechanical and thermal behavior. Macromol Chem Phys 197 431-441... 

Chemistry Polyurethane is produced by the reaction of a polyol with an diisocyanate (or in some instances a polyisocyanate) in the presence of catalysts. The polyols of choice are poly(propylene glycol), block copolymers of ethylene oxide (10-15%) with propylene oxide, or the newer polymer polyols (based on polymers such as polystyrene or styrene-acrylonitrile copolymer). Polyester diols such as polycaprolactone diol can be used in place of the polyether polyol in this reaction. The isocyanate of choice is a mixture of the 2,4 and 2,6 isomers of tolylene di-isocyanate in the ratio of 80 20, generally referred to as 80 20TDI. Other isocyanates such as diphenylmethane di-isocyanate (MDI), hexamethylene di-isocyanate (HMDI), and isophorone di-isocyanate (IPDI) are also used. A tin-based or amine catalyst is used to promote the reaction. Given the wide choice of reactants available, the reaction can yield foams with a range of different mechanical and thermal characteristics. 

In this study, the thermal characteristics of self-doped polyanilines was investigated. It was suggested that additional H-bonding introduced into poly anilines by the presence of carboxylic acids might increase its thermal stability. However, thermogravimetric thermograms of the copolymers were identical to polyaniline. 

Ward TC, Kalista SJ (2007) Thermal characteristics of the self-healing response in poly (ethylene-co-methacrylic acid) copolymers. J R Soc Interface 4 405 11... 

In the present study, we have investigated the synthesis of OVE from CO2 and GVE in view of the characteristics of phase transfer catalysts and reaction mechanism as well as its application with acylonitrile(AN) to the synthesis of corresponding copolymer. We have tested monomer reaetivity ratio and thermal properties of the copolymer. The blends of poly(OVE-co-AN) and SAN were prepared, and the degree of miscibility was examined by... 

Early studies of the thermal degradation of so-called polyarylates were covered by Neiman [100] and Ehlers and co-workers [101]. Since then, several highly aromatic and specifically liquid crystalline (mesogenic) polyesters have been examined in terms of their anaerobic thermal degradation characteristics. These inclnde homopolymers of hydroxybenzoic acids [102-105] copolymers of hydroxybenzoic acid with hydroxynaphthoic acid [105-108] polymers which are essentially copolymers of hydroxybenzoic acid and alkyene terephthalates [107-118] copolymers of hydroxybenzoic acid with other aromatic polyesters [119-122] phenolic and bisphenolic terephthalates [123-127] poly(oxynaphthoate)s [128] and liquid crystal polyesters (LCP) containing unsaturated acids as part of a copolyester chain [129-131]. 

Attwood, D., Tait, C.J. and Collett,J.H. (1987) Thermally reversible gelation characteristics, poly(oxyethy-lene)-poly(oxypropylene) block copolymer in aqueou.s solution after exposure to high-energy irradiation (Chapter 10), in Controlled-Release Technology Pharmaceutical Applications, Lee P.I., and Good, W. (eds), American Chemical Society, Washington D.C. 

Polyanhydrides have been characterized with regard to their chemical composition, structure, crystallinity and thermal properties, mechanical properties, thermodynamic properties, and hydrols c stability A representative set of analysis data has been summarized for the polyanhydrides poly(EAD-SA) and poly(CPP-SA) (Table 4). H NMR spectroscopy indicates the degree of randomness that suggests whether the polyanhydrides is either a random or a block copolymer the average length of sequence (Ln) and the frequency of occurrence of specific comonomers sequences (58). The anhydride bond presents characteristic peaks in... 

Fig. 50 Activation energies for oxidation obtained from different kinetic characteristics for thermal oxidation of butadiene a-methyl styrene copolymer (black), poly(p-divinyl benzene (grey) and polystyrene (white). The data were taken from [06J2].

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