Crystallization of Poly(di-n-butylsilane) from Solution

Single crystal lamellae and lamellar aggregates of poly(di-n-butylsilane) (PDBS) were grown by isothermal precipitation (35.0-50.0C) from dilute (0.001-0.10%) solutions of high molecular weight polymer (M sub w = 695,000) in n-decane and were studied by transmission electron microscopy and electron diffraction. The variety of morphologies observed was particularly dependent upon solution concentration. At 45C and 0.1% concentration, heavily overgrown aggregates of lamellae 10-12 nm thick had highly serrated edges. At 0.001% and the same growth temperature, two populations of lamellar crystals of the same thickness, but more regular lateral edges, were found with rhombic and rectangular habits, respectively.