ABSTRACT
Many of the distinctive properties of polymers are a consequence of the long chain lengths, which are reflected in the large molar masses of these substances. Although such large molar masses are now taken for granted, it was difficult in 1920 to believe and accept that these values were real and not just caused by the aggregation of much smaller molecules. Values of the order of 10
g mol
are now accepted without question, but the accuracy of the measurements is much lower than for simple molecules. This is not surprising, especially when polymer samples exhibit polydispersity, and the molar mass is, at best, an average dependent on the particular method of measurement used. Estimation of the molar mass of a polymer is of considerable importance, as the chain length can be a controlling factor in determining solubility, elasticity, fiber-forming capacity, tear strength, and impact strength in many polymers.
