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The crystallization behavior of poly(ethylene terephthalate) (PET, IV∼2dL/g) from solution in biphenyl–diphenyl ether mixed solvent is examined. Reversible gelation of the polymer solution is observed during cooling of the solutions. Light scattering and DSC analysis are used to follow the heating and cooling processes, thus determining the crystallization temperature and the melting point, which...
We have examined the influence of the solvent mixture diphenyl ether–biphenyl (DPE–BP) on the post-polymerization of poly(ethylene terephthalate) (PET) of intrinsic viscosity (IV=0.42dL/g) in the swollen state and in solution, by following the IV increase and the end-group depletion. During the swollen state polymerization (SwSP) of thin disks (180μm) at 195°C, the initially rapid step growth polymerization...
We have examined the influence of reaction environment on the solid-state polymerization (SSP) of thin (180 μm) poly(ethylene terephthalate) (PET) chips at 250 °C by following the intrinsic viscosity (IV) increase and the end-group depletion. When the SSP reaction is carried out in vacuum, IV increases from 0.58 to 2.4dl/g in 2.5 h of reaction. The initially rapid reaction slows considerably with...
Conditions are determined for the carbodiimide-mediated room temperature esterification of the carboxylic acid end-groups of poly(ethylene terephthalate) with hexafluoroisopropanol. The hexafluoroisopropyl ester is quantified with 19 F NMR, using α,α,α-trifluorotoluene as a secondary standard. This provides a technique for accurate determination of minute amounts of carboxylic acid functionality...
A series of surfactant-free monodisperse latices were prepared with varying glass transition temperatures (Tg) and particle sizes using methyl methacrylate (MMA) and butyl acrylate (BA) monomers. Latices with Tgs between −11 and 105°C were synthesized by varying the MMA to BA ratio during batch polymerization. The particle size of latices with a Tg of 19°C was varied by independently changing temperature,...
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