ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The solution behavior of polyglucoses prepared by the acid catalyzed polycondensation of Pacsu and Mora is discussed. According to this method glucose enters the polycondensation through the hemiacetal hydroxyl joining any of the other hydroxyls of a second glucose unit. Branching occurs up to the functionality of glucose but infinite network is not formed since the branching probability can only approach but never reach unity. The resulting polyglucose is a highly branched spherical molecule, readily soluble in water. Each polyglucose molecule contains one unreacted glucosidic hydroxyl in accordance with the suggested polycondensation scheme, as the agreement between osmotic and reducing end group number-average molecular weights indicate. The intrinsic viscosity is very low ([η] = 0.08 at Mw 100,000) and increases only slightly with the weight-average molecular weight, suggesting that the molecule is highly branched: a double logarithmic plot of [η] against Mw has a downward curvature and does not follow the straight line with a slope of 0.50, valid for linear molecules. Periodate oxidation data indicate that fractionation occurs not only by molecular weight but also by the extent of branching, and the lower molecular weight products appear to have relatively less branching.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1957.1202310330
