Syndiotactic polystyrene characterization

Syndiotactic polystyrene, s-PS, is a highly stereoregular, semicrystalline vinyl polymer that normally melts at 270 °C [45,46], S-PS shows a large number of crystalline polymorphs [47-50] obtained by melt crystallization and solvent-exposure techniques. However, s-PS assumes only two distinct crystalline conformations [all trans, planar zigzag (... tttttttt...) and 2 -helical (... ttggttgg. ..) t= trans and g = gauche], which are characterized by fiber repeats of... 

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. 

S. Bruzaud, Y. Grohens, S. Ilinca, and J.-F. Carpentier, Syndiotactic polystyrene/ organoclay nanocomposites Synthesis via in situ coordination-insertion polymerization and preliminary characterization. Macromolecular Materials and Engineering, 290 (2005), 1106-14. 

Syndiotactic polystyrene (sPS) is a semicrystalline polymer characterized by a glass transition temperature of 100°C and a melting temperature of 280°C. It has been widely investigated for the peculiar nanocavities that can be induced by carefully controlling its crystalline forms, but no studies are available at present on the foaming with blowing agents. 

Su, C.H., Jeng, U., Chen, S,H Cheng, C.-Y, Lee, J.-J., Lee, Y.-H. et al, (2009) Thermodynamic characterization of polymorphs in bulk-crystallized syndiotactic polystyrene via small/wide-angle X-ray scattering and differential... 

Sorrentino, A., Pantani, R., Titomanlio, G. Kinetics of melting and characterization of the thermodynamic and kinetic properties of syndiotactic polystyrene. J. Polym. Set Part B Polym. Phys., 45,196-207 (2007). 

Nitta, K., Nakatani, H., Yamada, H., Yamaguchi, M., Soga, K. Mechanical characterization of the crystalhzing mechanism of syndiotactic polystyrene. Macromolecules, 31(10), 3317-3321 (1998). 

The precise synthesis by homogeneous catalysts created a new polymer, syndiotactic polystyrene (SPS), in 1985. SPS is categorized as an engineering plastic based on its performance. Since the discovery of SPS, many studies have been done to characterize and understand the nature of SPS. In this chapter, the properties of SPS are presented in terms of rheological, mechanical, and electrical properties. 

Yamasaki, K., Tomotsu, N., Malanga, M. Characterization, properties and applications of syndiotactic polystyrene. In Modern Styrenic Polymers Polystyrenes and Styrenic Copolymers, Scheirs, J., Priddy, D. B. (eds.), John Wiley Sons, New York, 2003, pp. 389-409. 

The preparation and characterization of novel syndiotactic polystyrene/ 44 polyamide-6/sulfonated syndiotactic polystyrene/dodecylamine-modified montmorillonite (SPS/PA6/SSPS/MTA) nanocomposite by a melt-intercalation-blend process... 

Syndiotactic polystyrene synthesis, characterization, processing, and applications /... 

Kumar, S., Rath, T., Mahaling, R.N., Das, C.K., Processing and characterization of carbon nanofiber/syndiotactic polystyrene composites in the absence and presence of liquid crystalline polymer . Composites A 38,1304-1317 (2007). 

In this study, we investigated the structure development of uni- or biaxial film stretching for syndiotactic polystyrene cast film. The films were characterized by differential scanning calorimetry, and x-ray diffraction. Mechanical properties of the films were also measured by Instron tensile tester. 

The affect of polymer stereoregularity in the chains on the PAL data has also been studied. Hamielec et al [56] found what appears to be an increased lifetime (hole size) with increased randomness of the chain configuration in a series of polyvinlychloride (PVC) polymers, despite the large degree of scatter in the sample (probably due to the fact that a series of commercially available products were used.). They however found little correlation with tacticity in polypropylene. More recently a PAL study on a series of very well characterized polystyrene and poly(p-methlystyrene) samples of differing tacticity [57] was performed. In addition to finding that the polystyrene samples have smaller free volume holes than the poly(p-methylstyrene) samples, they found that the syndiotactic samples had broader hole distributions than the attactic samples. 

Isotactic and syndiotactic polymers can crystallize, while atactic polymers cannot. Polymers other than polypropylene that have tacticity include polystyrene, polyfvinyl chloride), and poly(methyl methacrylate). Thus there are crystalline and non-crystalline forms of these polymers. By use of a copolymer, the number of side groups, and thus the crystallinity can be precisely controlled. An important example is the copolymerization of ethylene and a higher alpha-olefin, such as butene or octane, to make linear low-density polyethylene (LLDPE), in which the crystallinity is governed by the fraction of comonomer incorporated into the chain. Tacticity can affect important physical properties such as the intrinsic viscosity and thus must be taken into accoimt in characterization methods such as gel permeation chromatography. 

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