Polymer physicochemical characterization

The cyclotrisilazane (R = Me) produced in reaction (14) is recycled at 650°C [by reaction with MeNHo) the reverse of reaction (14)] to increase the yield of processible polymer. Physicochemical characterization of this material shows it to have a softening point at 190°C and a C Si ratio of 1 1.18. Filaments 5-18 pm in diameter can be spun at 315°C. The precursor fiber is then rendered infusible by exposure to air and transformed into a ceramic fiber by heating to 1200°C under N2- The ceramic yield is on the order of 54% although, the composition of the resulting amorphous product is not reported. The approach used by Verbeek is quite similar to that employed by Yajima et al. (13) in the pyrolytic preparation of polycarbosilane and its transformation into SiC fibers. 

The aim of this chapter is to summarize some of the research findings on xylan, a natural polymer extracted from corn cobs, which presents a promising application in the development of colon-specific drug carriers. Physicochemical characterization of the polymer regarding particle size and morphology, composition, rheology, thermal behavior, and crystallinity will be provided. Additionally, research data on its extraction and the development of microparticles based on xylan and prepared by different methods will also be presented and discussed. 

Zhang, Y., Yang, Y., Tang, K., Hu, X., Zou, G. (2008). Physicochemical characterization and antioxidant activity of quercetin-loaded chitosan nanoparticles. Journal of Applied Polymer Science, 107, 891-897. 

Hoekstra, H.D. Spoormaker, J.L. Breen, J. Audoouin, L. Verdu, J. UV-exposure of stabilized and non-stabilized HDPE films physicochemical characterization. Polym. Degrad. Stab. 1995, 49, 251-262. 

A definitive picture of the phase structure emerged and was made possible by the simultaneous development of powerful investigative techniques such as phase staining/electron micrography, low-angle X-ray diffraction, and GPC which were combined with conventional physicochemical characterizations of bulk, melt, and solution states of the block polymers. 

However, before the translation can be made to a marketed product containing modified chitosan as an excipient, extensive preclinical studies, including toxicological studies, as well as clinical studies are required. Moreover, scaling up of the chemical synthesis and precise physicochemical characterization of the novel polymers will be needed. 

SAK Sakar, D., Erdogan, T., Cankurtaran, O., Hizal, G., Karaman, F., and Tunca, U., Physicochemical characterization of poly(teri-bntyl aciylate-Z)-methyl methacrylate) prepared with atom transfer radical polymerization by inverse gas chromatography, Polymer, 47, 132, 2006. 

Although FDA does not have specific guidance for biocompatibility testing of polymers, the hitemational Standard ISO-10993 is recommended by the FDA for biological evaluation of biomedical devices. ISO-10993 entails 20 detailed standards to evaluate the biocompatibihty of a material device prior to clinical testing. These tests include both in vitro and in vivo assays as well as physicochemical characterization... 

Yen, M., Yang, J., Mau, J. Physicochemical characterization of chitin and chitosan from crab shells Carbohydr. Polym. 75, 15-21 (2009)... 

Preparation of biodegradable polymer-based layered silicate nanocomposites, physicochemical characterization, biodegradability, and future prospects are discussed. The chapter also discusses the preparation and characterization of biodegradable polymer-based blends. 

Jang, M.K., Kong, B.G., Jeong, Y.I., Lee, C.H., and J.W. Nah. 2004. Physicochemical characterization of a-chitin, P-chitin and x-chitin separated from natural resources. Journal of Polymer Science Part A Polymer Chemistry 42 3423-3432. 

A.S. Singha and V.K. Thakur, Morphological, thermal, and physicochemical characterization of surface modified pinus fibers. Int. J. Polym. Anal. Charact. 14, 271-289 (2009). 

Ciolino, A. E. Gomez, L. R. Vega, D. A. Villar, M. A. Valle, E. R., Synthesis and Physicochemical Characterization of a Well-Defined Poly(butadiene l,3)-l)Zock-Poly(dimethylsiloxane) Copolymer. Polymer 2008,49,5191-5194. 

Yen M, Yang J, Mau J (2009) physicochemical characterization of chitin and chitosan liom crab shells. Carbohydr Polym 75 15-21... 

Lecomte, F., Siepmann, J., Walther, M., MacRae, R.J., Bodmeier, R., 2003. Blends of enteric and GIT-insoluble polymers used for film coating physicochemical characterization and drug release patterns. Journal of Controlled Release 89, 457—471. 

Keshk, S.M.A.S., Suwinarti, W., Sameshima, K., 2006b. Physicochemical characterization of different treatment sequences on kenaf bast fiber. Carbohydrate Polymers 65, 202. 

Inorganic-polymer nanocomposites characterized by exceptional dielectric constant are often called artificial dielectrics . Artificial dielectrics are created when isolated particles become polarized due to the presence of an applied electric field. These novel nanocomposite artificial dielectrics have the potential to posses high dielectric constants (>100) at high frequencies and the low processing temperature associated with polymers. Such a combination of properties is not found in other capacitor materials [180]. Polymer matrices like PMMA, poly(vinylidene fluoride) (PVDF), PS, and polyurethane (PU) have been used. Owing to their physicochemical properties, they represent suitable polymer components for embedding nanoscopic functional inorganic fillers (Table 2). 

PA. McCarron, A.D. Woolfson, R.F. Donnely, G.P. Andrews, A. Zawislak, and J.H. Price, Influence of plasticizer type and storage conditions on properties of poly(methyl vinyl ether-co-maleic anhydride) bioadhesive films,/. Appl Polym. Sci., 91,1576-1589,2004. T.R.R. Singh, PA. McCarron, A.D. Woolfson, and R.F. Donnelly, Physicochemical characterization of poly(ethylene glycol) plasticized poly(methyl vinyl ether-co-maleic acid) films, /. Appl. Polym. Sci., 112, 2792-2799, 2009. 

The structure of a polymer determines its physicochemical and mechanical properties and vith that its technical applicability. Typically, polymers contain a backbone, a long chain that goes through the whole molecule. This backbone can be formed only by one sort of atom (like in polyethylene) or by more than one sort of atoms (polyesters, polypeptides). It can be formed from one monomer only (homopolymers) or by different monomers (copolymers). In general terms the structure of a polymer is characterized by the following parameters ... 

The polyamide obtained by polycondensation of 2,6-diaminopyridine and 2,6-pyridine dicarboxylic acid was the first polymer to assemble itself into a double helix (DNA-type) in solution. The synthesis and physicochemical characterization of some polymer-supported rhodium catalysts based on polyamides containing 2,6- and 2,5-pyridine units were reported by Michalska and Strzelec (2000) these catalysts were used for the hydrosilylation of vinyl compounds such as phenylacetylene. Chevallier et al. (2002) prepared polyamide-esters from 2,6-pyridine dicarboxylic acid and thanolamine derivatives and investigated their polymer sorption behavior towards heavy metal ions. Finally, Scorlanu et al. (2006) also prepared a polymer with improved performance based on polyureas containing 2,6-pyridine moiety and polyparabanic acids, and polymethane-ureas containing 2,6-pyridine rings. 

Michalska, Z. M., Strzelec, K. (2000), Synthesis and physicochemical characterization of polymeric supports and polymer-supported rhodium catalysts based on polyamides having a pyridine moiety. Reactive Functional Polymers, 44,189-99. 

The evidence comes from a variety of sources from Investigations on rubber elasticity, chemical cycllzatlon equilibria, thermodynamics of solutions, and, most recently, from neutron scattering studies on protonated polymers In deuterated hosts (or vice versa).The Investigations last mentioned go further. They confirm the prediction made twenty-five years ago that the excluded volume perturbation should be annulled in the bulk amorphous state. The excluded volume effect is therefore an aberration of the dilute solution, which, unfortunately. Is the medium preferred for physicochemical characterization of macromolecules. 

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