Polyester molecular weight data

Simultaneous Determination of Molecular Weight Data and Monomers of a Polyester, Hewlett Packard HPLC Application 87-5, Gel Permeation Chromatography 1987. 

In this paper, we try to review results obtained from anionic copolymerization of cyclic ethers with cyclic anhydrides. For a better understanding data and theoretical views on non-catalyzed copolymerizations are also included. We concentrate mainly on the kinetics and mechanism of copolymerization and the effect of the type and character of the initiator used. The influence of the epoxide and anhydride structure on copolymerization, of proton donors on the rate and course of copolymerization, and on the molecular weight of the resulting polyesters are also discussed. 

Data on molecular weights of polyesters can provide information on the mechanism and termination and transfer reactions. As follows from section 3.2.3 the copolymerization of epoxides with cyclic anhydrides should proceed stoichiometrically without transfer or termination reactions, and the average degrees of copolymerization should only depend on the molar ratio of monomers to the initiator. Polymers with a narrow molecular Weight distribution should be obtained. 

The polyesters made from polyols like glycol, glycerol, pentaerythritol and dicar-boxylic acids like adipic, sebacetic, azelaic acids as starting materials easily reach a molecular weight above 1,000 Daltons. It is well established that molecules with molecular weights above 1,000 normally show a very reduced bioavailability. Data show that esters are in principle hydrolyzed, however those at higher molecular... 

Problem 5.4 In another series of experiments similar to those in Problem 5.1 the low-molecular weight polyester corresponding to 82% conversion of the original COOH groups were further polymerized at 161°C in the presence of p-toluene sulfonic acid (0.004 mol per mol of polymer) yielding the following conversion data [5] of the end hydroxyl and carboxyl acid groups ... 

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. 

J/n < 6,000). Often, no analytical data or structural characterization was provided. Room-temperature interfacial polycondensation methods were also investigated as a convenient alternative to classical polycondensations. Such methods were first reported for the preparation of polyamides and polyesters from the reaction of l,l -ferrocenyldi-carbonyl chloride with several diamines and diols. The synthesis of polyurethanes using this technique was also reported and involved the condensation of l,T-ferrocenedimethanol and l,T-bis(dihydroxyethyl)ferrocene with diisocyanates. Once again, however, these polymers possessed low molecular weights.The early research in these areas has been summarized and critically reviewed and will not be discussed further here. ... 

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