Polyformals characterization

The polyformal (I) was characterized by wet chemical and infrared analyses, and by cryoscopic molecular weight determinations. For the latter, the preferred method was the freezing point depression of an ethylene bromide solution. The other polyacetals were characterized primarily by infrared analysis and molecular weight determinations. 

Spin relaxation in dilute solution has been employed to characterize local chain motion in several polymers with aromatic backbone units. The two general types examined so far are polyphenylene oxides (1-2) and aromatic polycarbonates (3-5) and these two types are the most common high impact resistant engineering plastics. The polymer considered in this report is an aromatic polyformal (see Figure 1) where the aromatic unit is identical to that of one of the polycarbonates. This polymer has a similar dynamic mechanical spectrum to the impact resistant polycarbonates (6 ) and is therefore an interesting system for comparison of chain dynamics. 

Table 1. Synthesis and Characterization of 4,4 -Dihydroxy-a-methylstilbene Polyformal and Polyethers... 

Preliminary information on new aromatic polyformals based on other bisphenols is contained in Table 7. Most of these materials have been made only once and no extensive characterization of the polymers has been made. None of these polyformals were examined for cyclic oligomers. Where possible, the T for the corresponding polycarbonate is also given. All polymerizations were run in NMP/ CH9CI9 mixtures except when the bisphenol contained an electron 0... 

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See also in sourсe #XX -- [ ]

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