Ethylene glycol chain extender effects

C. Ethylene Glycol Chain Extender Effects. Figure 6 shows the polymerization viscosity-time-temperature relations for a thermoplastic poly(ester-urethane) elastomer, Polymer 10, made from monomers VII, IV, and XI (Table I). VII is low acid number PTAd (0.15) and XI is ethylene glycol chain extender. The polymerization charge also contained 0.25% (on charge) of Irganox 1010 antioxidant. 

The effect of different glycol chain extenders is given in Table 3.14, which shows the effect of the nature of these diol chain extenders. Note the low compression set obtained with ethylene glycol. 

When MDI was used in the polymer synthesis, irrespective of the synthesis route it obtained homogeneous soluble polymers inseparable in fractions, by selective dissolution in DMF. Certainly, the sequence of ordering on the macromolecular chain differs from a PU synthesis route to another. As mentioned, the reaction rate between phenyl isocyanate (FI) and chain extender, ethylene glycol (EG) was found by us to be 4 times higher than the reaction between FI and PEA when measured separately, and 11.6 higher respectively if they are in a mixture (EG + PEA) (synergetic effect) [45,89]. 

The results are reported of a study of the mechanism of stabilisation during vinyl acetate-ethylene emulsion copolymerisation using various colloidal stabilisers. These stabilisers included PVAl, aUcylphenol ethoxylate and a diisocyanate chain extended polyethylene glycol. The effects of these stabilisers on emulsion characteristics, film properties and applications behaviour are discussed. 5 refs. (217th ACS National Meeting, Anaheim, Calif., 21-25 March, 1999)... 

Poly(ethylene glycol) has been chain extended to a high molecular weight amorphous rubbery linear polymer using an oxymethylene link." This polymer, when doped with lithium perchlorate, shows similar conductivity to MEEP and because of its chemical similarity to PEO provides an interesting comparison to show the effect of crystallinity." ... 

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