Controlling Polymer Crystallization Kinetics by Sample History

• DOI: 10.1002/macp.201700315
• Publication Date: 2017-08-23T17:18:40Z
• Authors: Purushottam Poudel; Sivasurender Chan...; Sumit Majumder; Günter Reiter
• Keywords: Reptation; Tacticity; Polystyrene; Isothermal process

Abstract In this paper systematic changes in the isothermal crystallization kinetics (at T c = 200 °C) of nonequilibrated isotactic polystyrene films, generated through spin coating are reported. Kinetics is tuned by annealing films at a 250 °C, i.e., above their nominal melting temperature ( m DSC 220 °C). An exponential decrease growth rate and significant crystal nucleation density approximately three orders magnitude observed increasing time t ) provided for equilibration . The characteristic decay four longer than equilibrium reptation Interestingly, with , change morphology lamellar crystals varying from spherulites to hexagons rather uniform height finally exhibiting periodic modulations observed. These observations reveal that understanding tuning polymer under quiescent conditions requires knowledge on how strongly chain conformations deviate equilibrium.