A kinetic study of polymer crystallization from solution

The crystallization of moderately dilute solutions ( ca. 1%) of poly(decamethylene terephthalate) in 1,2‐dichloroethane has been studied by microscopy and light scattering and it has been found that a well‐defined transition occurs in the growth rate for the crystallizing particles. The transition occurs at an average size of ca. 2.5 · 10 −5 cm., and probably represents the change from single crystal to polycrystal growth. Both stages of growth show a linear increase in dimensions with time, but the growth rate for the first stage is approximately twenty times less than that for the second. The nuclei responsible for initiating growth stem from heterogeneities, but their extremely small size (< 100 Å.) makes it unlikely that they are adventitious solid impurities. An alternative is that they may be associated with abnormalities in the polymer molecules themselves, involving chemically‐modified sites in the chains.