Styrene thermodynamic properties

B 9. Boyer, R. F., and R. S. Spencer Some thermodynamic properties of slighty cross-linked styrene-divinylbenzene gels. J. Polymer Sci. 3, 97 (1948). 

KAR Karagoz, M.H., Zorer, O.S., and liter, Z., Analysis of physical and thermodynamic properties of poly(2-phenyl-l,3-dioxolane-4-yl-methyl-methaciylate-co-styrene) with inverse gas chromatography, Polym.-Plast. Technol. Eng., 45, 785, 2006. 

The use of halogenated monomers or reactive intermediates can bring about a lowering of heat of combustion. For example, heat capacity and heat of combustion have been determined for copolymers of styrene with polyesters whose thermodynamic properties were known introduction of chlorine into the polyester molecule lowered the heat of combustion. The temperatures of self-ignition of polyesters containing 17.5% and 23.7% chlorine were 580 and 650 °C, respectively. 

The two monomers of major interest, styrene and ethylene, are well known and details can be found on all aspects of their technology elsewhere. Poly(ethylene-co-styrene) is primarily produced via solution polymerization techniques using metallocene catalyst/co-catalyst systems, analogous to the production of copolymers of ethylene with a-olefin monomers. Solvents that can be employed include ethyl-benzene, toluene, cyclohexane, and mixed alkanes (such as ISO PAR E, available from Exxon). The thermodynamic properties of poly(ethylene-co-styrene), including solvent interactions and solubility parameter assessments, are important factors in relation to polymer manufacture and processing, and have been reported by Hamedi and co-workers (41). 

KA5 Kaya, I. and Mart, H., Determination of thermodynamic properties of poly(4-fe/ f-butyl-styrene) by inverse gas chromatography, J. Polym. Eng., 19, 197, 1999. 

Second virial coefficient of poly(decyl methacrylate-b-styrene) Data extract from Landolt-Bornstein VIII/6D2 Polymers, Polymer Solutions, Physical Properties and their Relations I (Thermodynamic Properties PVT-data and miscellaneous properties of polymer solutions) ... 

In conclusion, phase transfer catalyzed Williamson etherification and Wittig vinylation provided convenient methods for the synthesis of polyaromatics with terminal or pendant styrene-type vinyl groups. Both these polyaromatics appear to be a very promising class of thermally reactive oligomers which can be used to tailor the physical properties of the thermally obtained networks. Research is in progress in order to further elucidate the thermal polymerization mechanism and to exploit the thermodynamic reversibility of this curing reaction. 

This dependence of block polymer property on casting solvent also is seen in poly(styrene-b-diene) polymers (28). Theoretical work (23) has shown that the thermodynamically most stable morphology for a diblock polymer containing 50% of each component is a lamella morphology. For this reason MEK was chosen for the tests on all other polymers. 

Grater, H. Schuster, R. H. Cantow, H.-J., "Thermodynamics of Polymer Systems. 5. Sorption and Mixing Properties of Selected Solutes and Solubility Parameters of Atactic Poly(Styrene) by Gas Chromatography," Polym. Bull., 14, 379 (1985). 

The formulation of two types of ion-pair is an attractive hypothesis which has been used for other systems [130] to explain differences in reactivity. The polymerization of styrene-type monomers in ether solvents, all of which solvate small cations efficiently, seems to be a particularly favourable case for the formation of thermodynamically distinct species. Situations can be visualized, however, in which two distinct species do not exist but only a more gradual change in properties of the ion-pair occurs as the solvent properties are changed. These possibilities, together with the factors influencing solvent-separated ion-pair formation, are discussed elsewhere [131, 132]. In the present case some of the temperature variation of rate coefficient could be explained in terms of better solvation of the transition state by the more basic ethers, a factor which will increase at lower temperatures [111]. This could produce a decrease in activation energy, particularly at low temperatures. It would, however, be difficult to explain the whole of the fep versus 1/T curve in tetrahydrofuran with its double inflection by this hypothesis and the independent spectroscopic and conductimetric evidence lends confidence to the whole scheme. 

The system styrene-acrylonitrile copolymer (SAN) 28% acrylonitrile/ poly (methyl methacrylate) exhibits thermodynamic solubility relationships adequate for studying phase transition phenomena. The molecular weight properties of the polymers used in this study (Table III) were measured by gel permeation chromatography. The cloud-point curve for binary mixtures of these two polymers was determined by a technique developed previously (10). 

The comprehensive characterization of uitrathin resist (UTR) (<100 nm) processes in terms of defectivity, manufacturahility, and physical properties (structure, dynamics, stability, thermodynamic behavior, etc.) have been a central point of interest in semiconductor microlithography for quite some time. Despite many years of experimental and theoretical efforts along these lines, a number of basic questions still remain to be answered. One of these issues is the fundamental lower physical limit of the resist thickness, below which lithographic patterning is not viable. For resists based on the polyhydroxy styrene platform, this lower limit has been determined to be around 60 nm, with the onset of film instability occurring at around 55 nm. For a host of other resist platforms, this lower limit is yet to be determined. 

CR2 Cramond, D.N. and Urwin, J.R., Solution properties of block copolymers of poly(isoprene-styrene) 11. Thermodynamic parameters from osmotic data, Eur. Polym. J., 5, 45, 1969. 

KOT Kotaka, T., Ohnuma, H., and Inagaki, H., Thermodynamic and conformational properties of styrene-methyl methacrylate block copolymers in dilute solution. 11-Behavior in theta solvents. Polymer, 10, 517, 1969. 

De Sarkar, M., De, P.P., Bhowmick A.K, (1997). Thermoplastic elastomeric hydrogenated styrene-butadiene elastomers Optimization of reaction conditions, thermodynamics and kinetics. Journal of Applied Polymer Science, Vol.66, No. 6, p>p. 1151-1162 Dresselhaus, M., Dresselhaus, G., Avouris, Ph. (2001). Carbon Nanotubes. Synthesis, structure, properties and applications. Springer, ISBN 3-540-41086-4, Verlag Berlin Heidelberg, Germany... 

Another aspect of thermal analysis concerns the thermodynamic functions based on heat capacity. Obviously, the number of possible copolymers is so large, that complete measurements for all copolymers are not possible. Fortunately, the heat capacity of glassy and liquid copolymers over wide temperature ranges are not structure sensitive (for a discussion of structure-sensitive properties see Sect. 5.3.1). A simple additivity mle based on the molar composition of the components is suggested in Fig. 2.70 for the copolymers of styrene and butadiene (see also the addition scheme of heat capacities in Fig. 2.77). 

---