Poly polymer characterization

Figure 7.10 Nuclear magnetic resonance spectra of three poly(methyl methacrylate samples. Curves are labeled according to the preominant tacticity of samples. [From D. W. McCall and W. P. Slichter, in Newer Methods of Polymer Characterization, B. Ke (Ed.), Interscience, New York, 1964, used with permission.]...

The phenomena we discuss, phase separation and osmotic pressure, are developed with particular attention to their applications in polymer characterization. Phase separation can be used to fractionate poly disperse polymer specimens into samples in which the molecular weight distribution is more narrow. Osmostic pressure experiments can be used to provide absolute values for the number average molecular weight of a polymer. Alternative methods for both fractionation and molecular weight determination exist, but the methods discussed in this chapter occupy a place of prominence among the alternatives, both historically and in contemporary practice. 

Crystalline polymers characterized by disordered conformations of the chains are, for instance, polytetrafluoroethylene (PTFE), /ra .s-1,4-poly (1,3-butadiene), and cis-1,4-poly(isoprcnc). 

Poly(amido-amine)s are a class of polymers characterized by the presence of amido and amino groups regularly arranged along the macromolecular chain. Additional functional groups may be introduced as side substituents. 

Sikkema DJ, Hoogland P(1986) Poly(7-oxabicyclo[2.2.1]heptane-co-tetrahydrofumane) Polymerization, polymer characterization and spinning. Polymer 27 1443... 

From 1987 up to now, there are many reports in the literature related to the satisfactory use of MALDl to characterize polymer chains [31]. The first reports of polymer characterization by MALDl were published by Tanaka et al. [32] in 1988 describing the characterization of poly(propylene) and poly(ethylene glycol) (PEG) using MALDL... 

Polymers Characterized by HT-GPC A number of polymers can be characterized by GPC in 1,2,4-trichlorobenzene at an elevated temperature polyethylene, polypropylene, poly(ethylene-vinyl acetate), poly(ethylene-methyl acrylate), polyethylene propylene diamine rubber, different types of butyl rubber, and poly(phenylene oxide). In Table 17.3 are presented some common polymers, as well... 

Monomers in which F is substituted for Ft are also regarded as vinyl polymers. In tetrafluoroethylene CF2=CF2, all four hydrogens have been replaced by fluorine. The resultant polymer is poly(tetrafluoroethylene) (PTFE) or Teflon. PTFE is a polymer characterized by very low friction, giving it nonstick properties and very high chemical resistance. 

Maziarz, E.R, Baker, G.A., and Wood, T.D. Capitalizing on the high mass accuracy of electrospray ionization Fourier transform mass spectrometry for synthetic polymer characterization A detailed investigation of poly(dimethylsiloxane). Macromolecules, 32, 4411, 1999. 

Crystalline polymers characterized by disordered conformations of the chains are, for instance, polytetrafluoroethylene [10-12,49-54], cis-l,4-poly (isoprene) [100-102] and trans-1,4-poly( 1,3-butadiene) [8,9,55-58]. In these cases, disorder does not destroy the crystallinity because of the similar shape of the various conformational units. The occmrence of cases of conformational isomorphism of the first kind demonstrates that a polymer chain can remain straight, as if it was constrained to run inside the walls of a tight cylinder, while its conformational freedom remains of the same order of magnitude as that in the melt. 

Poly(ethylene tephthalate) (PET) is a crystalline polymer characterized by a triclinic unit cell. The chain axis is 10,7 A and corresponds to chains in fully extended conformation, with all dihedral bonds close to the trans-planar conformation (tf symmetry) [258], As shown in Fig. 30A, in this conformation, the terephthalic residues are all coplanar. 

A. Morisato, H. C. Shen, S. S. Sankar, B. D. Freeman, I. Pinnau, C. G. Casillas, Polymer characterization and gas permeability of poly(l-trimethylsilyl-l-propyne) [PTMSP], poly(l-phenyl-l-propyne) [PPP], and PTMSP/PPP blends, J. Polym. Sci. Part B Polym. Phys., 34, 2209-2222 (1996). 

Shin J.-H., Kondo X, Cellulosic blends with poly(acrylonitiile) Characterization of hydrogen bonds using regioselectively methylated cellulose derivatives. Polymer, 39, 1998, 6899-6904. 

J.B.P. Soares, A.E. Hamielec, Temperature rising elution hactimiatimi, in Modem Techniques for Polymer Characterization, ed. by R. A. Pethrick, J. V. Dawkins (Wiley, New Yrak/ChichestCT, 1999) J.B.P. Soares, B. Monrabal, J. Nieto, B.J. Javier, Ciystallization analysis Ixactionation (CRYSTAF) of poly(ethylene-co-l-octene) made with single-site-type catalysts a mathematical model for the dependence of composition distribution on molecular weight. Macromol. Chem. Phys. 199, 1917-1926 (1998)... 

Polymerization of TOT, TTOTT and TTTOTTT leads to polymers characterized by the presence of one nonaromatic thienyl-5, S-dioxide moiety every two, four and six aromatic thienyl units. Table 4.2 shows that the oxidation potentials of the polymers (1.10, 1.08 and 0.98 V vs SCE, respectively) vary within a much smaller range than that of the corresponding oligomers and that they are comparable to those of polythiophene and alkylated polythiophenes. For example, poly(3,4-dimethyl)- and poly(3,4-diethyl)thiophenes have oxidation peak potentials of 1.00 and 1.10 V vs SCE, respectively [34]. Also, the range of variation of the reduction potentials is narrow (—1.20, —1.34 and —1.35 V vs SCE), but all the values are... 

CROP has been extensively used for preparing poly(2-oxazoline)s, an important biomedical polymer characterized by its structural similarities with the naturally occurring polypeptides. Commonly used initiators for this CROP include aliphatic... 

Bradley, D. D. C., Precursor-route poly(p-phenylenevinylene) polymer characterization and control of electronic properties, J. Phys. D Appl. Phys., 20, 1389-1410... 

M. D. Blanco, R. L. Sastre, C. Teijon, R. Olmo, J. M. Teijon, 5-Fluorouracil-loaded microspheres prepared by spray-drying poly(D,L-lactide) and poly(lactide-co-glycolide) polymers characterization and drug release, J. Microencapsul 2005, 22, 671-682. 

---