Syndiotactic polystyrene properties

Since the last edition several new materials have been aimounced. Many of these are based on metallocene catalyst technology. Besides the more obvious materials such as metallocene-catalysed polyethylene and polypropylene these also include syndiotactic polystyrenes, ethylene-styrene copolymers and cycloolefin polymers. Developments also continue with condensation polymers with several new polyester-type materials of interest for bottle-blowing and/or degradable plastics. New phenolic-type resins have also been announced. As with previous editions I have tried to explain the properties of these new materials in terms of their structure and morphology involving the principles laid down in the earlier chapters. 

Hong, B. K. and Jo, W. H. (2000) Effects of molecular weight of SEBS triblock copolymer on the morphology, impact strength, and rheological property of syndiotactic polystyrene/ ethylene-propylene rubber blends. Polymer, 41, 2069-2079. 

Syndiotactic polymerization, 76 99-102 Syndiotactic polymethacrylate esters, glass transition temperatures of, 76 273t Syndiotactic polypropylene, 20 524 Syndiotactic polystyrenes (SPS), 23 365 Syndiotactic polystyrene, 70 180-183 applications for, 70 183 properties of, 70 182... 

Polystyrene (PS), CAS 9003-53-6, is typically found in atactic and amorphous form. Isotactic and syndiotactic polystyrenes can be synthesized, but they are not used in practice since there are few advantages in properties compared to the atactic form. The reticulation of the carbon chains in polystyrene is frequently done using in the polymerization process a certain proportion of 1,4-divinyibenzene or less often of 1,3-divinylbenzene. The resulting polymer in the case of crosslinking with 1,4-divinylbenzene has the idealized structure shown below ... 

Syndiotactic polystyrene (sPS) represents an important achievement in olefin polymerization catalysis. Syndiotactic PS is an industrially relevant thermoplastic material produced by Dow Chemical and Idemitsu Kosan Co. under the tradenames Questra and Xarec , respectively. Industrial interest on sPS originates from the remarkable properties exhibited by this highly crystalline polymer. The high melting temperature, 270 °C, the relatively fast crystallization rate (at least much faster than that of iPS), the high heat resistance, the low dielectric constant, the high elastic modulus, and an excellent resistance to chemicals explain the industrial interest for this material. Syndiotactic PS was considered as an innovative new resin option for the automotive, electrical, and electronic markets, appliances such as... 

Recovery of properties may be based on specific polymers and their blends (viz. syndiotactic polystyrene, polyesteretherimide, some blends of polyphenyleneether) that have been shown to maintain high performance for at least 5-10 re-extrusions. It has been also shown that properly stabilized resins (e.g., polyolefins) are able to maintain performance for at least five re-extrusions [Herbst et ah, 1997]. 

The mutual repulsion between substituents may cause some displacement. As a result, the plane of symmetry is bent in the form of a helix. This occurs also in biopolymers (double-helix of deoxyribonucleic acid (DNA)). Different stereoisomers have different mechanical and thermal properties. For example, atactic polystyrene is an amorphous polymer whereas syndiotactic polystyrene is a crystalline substance. The chemical design of macromolecules determines their properties as extent of crystallization, melting point, softening (glass transition temperature), and chain flexibility which in turn strongly influence mechanical properties of the materials. 

Properties depend on rubber content. SPS is syndiotactic polystyrene. 

Mahesh K P O, Sivakumar M, Yamamoto Y, Tsujita Y, Yoshimizu FI, Okamoto S (2004) Structure and properties of the mesophase of syndiotactic polyst3n-ene. Vin. Solvent sorption behavior of syndiotactic polystyrene/p-chlorotoluene mesophase membranes. J. Polym. Sci. Part B Polym. Phys. 42 3439-3446... 

In the present text we attempt to do justice to the different topics of polymers and their uses. This text is generally suitable for researchers rather than students. The first chapter of this book discussed sorption mechanism of organic compound in the nanopore of syndiotactic polystyrene crystal. In the second chapter, a discussion was done to illustrate a physico-chemical characterization and processing of pulse seeds. The chemo-enzymatic polymerization for peptide polymers were illustrated in the third chapter. In the fourth chapter, an electrokinetic potential method was used to characterize the surface properties of polymer foils and their modifications. Also, an emulsion polymerizations was discussed in the fifth chapter. Nonconventional methods of polymer surface patterning, polymer characterization using atomic force microscope, biopolymers in the environment, and carbon nanostructure and their properties and applications were discussed in the sixth, seventh, eighth and ninth chapters respectively. Finally, let us point that although many books in the field of pol)nner science appear, none of them are complementary. 

An example of the latter is Dow s development of syndiotactic polystyrene, which has the properties of an engineering plastic. Also important is the incorporation of comonomers in a highly uniform manner. Again, Dow has produced an 80% ethylene/20% octane elastomer (89). Metallocene polymers have mainly been used in higher priced specialty applications (). 

---