Poly melting point data

Figure 2.46. Determination of equilibrium melting point for poly(2-methylpenta-methylene terephthalamide) by the Hoffman-Weeks method. Heating rate = 10 °C/ min. Melting point data obtained on samples isothermally crystallized at 252.5 °C, 260 °C, 267.5 °C and 275 °C were used to determine the equihbrium melting point. [From Menczel et al. (1996) reprinted with permission of Springer-Verlag.]...

The melting point data of poly(vinylidene fluoride) in the presence of poly(methyl methacrylate) or poly(ethyl methacrylate) obey the prediction of eq.fb), as shown in Fig. 5. The Bx2 values are -2.98 cal/cmP HyiMA and -2.86 cal/cm3 PEMA. The addition of a methylene group to the side chain of the methyl methacrylate polymer does not seem to have significant influence on its compatibility with PVF at elevated temperatures. 

The octene-1 and decene-1 units alter the poly-4-methylp tene-i lattice to a some extent The X-ray (Fig. 11) and melting-point data demonstrate and evident tendency to block formation in these cases also. 

The melting points of a series of poly(a-olefin) crystals were studied. All of the polymers were isotactic and had chain substituents of different bulkinesses. Table 4.2 lists some results. Use Eq. (4.5) as the basis for interpreting the trends in these data. 

With all six series of polyester illustrated in Figure 25.14, as the number of methylene groups in the repeating unit increases so the polymer becomes more like a linear polyethylene (polymethylene). Thus the melting points for five of the six classes are seen to converge towards that of the melting point of polymethylene. In the ca.se of the sixth class, the poly(alkylene adipates), there would appear no reason to believe that additional data on other specific members of the class would not lead to a similar conclusion. 

High-molecular-weight poly (thiol esters) show fiber-forming properties. This section covers the available data concerning melting points, crystallinity, solubility, and stability of this class of esters, and compares them with polyesters and polyamides. Information about spectra is also reviewed. 

The complete hydrogenation of poly(l,4-butadiene), cis or tmns structure, forms a polyethylene with a low melting point of about 115 C. It is believed that this linear polyethylene is a low-density material. Unpublished data obtained... 

S3. The dependenee of the melting points of zone-refined alkanes on the molecular weight. The melting point of a 100% crystalline poly(elhylene) of infinite molecular weight is given as 146.3 C. (From data of Figure 1-1 and from W. Heilz, R, Peters, G. Strobl, and E. W. Fischer. ... 

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