Flat-on lamellae in spin-coated, stable films of poly(propylene azelate).

Thin films (5-500 nm thick) of the linear aliphatic polyester (3,7) poly(propylene azelate) (PPAz) were prepared by spin-coating of CHCl(3) polymer solutions with different polymer concentrations. The morphology and structure of the spin-coated thin films were investigated by atomic force microscopy (AFM) and by grazing incidence wide-angle X-ray scattering (GIWAXS) techniques. AFM revealed the continuous nature of the flat, spherulitic films which are stable against dewetting even for polymer coatings as thin as 15 nm. GIWAXS patterns revealed a high crystal orientation of the films. A sharp reflection on the meridian whose spacing is related to the polymer chain unit length (c-axis) supports the presence of flat-on lamellae morphology in the whole range of film thicknesses investigated. The flat-on lamellae morphology is also supported by AFM images. A triclinic unit cell with the c*-axis perpendicular to the substrate is proposed for PPAz. The repulsion of the long aliphatic spacer by the Si-substrate is invoked as the main reason for the flat-on morphology observed.

[1]  A. Nogales,et al.  Structure and morphology of thin films of linear aliphatic polyesters prepared by spin-coating. , 2010, Langmuir : the ACS journal of surfaces and colloids.

[2]  M. Zanetti,et al.  Degradable polyoctamethylene suberate/clay nanocomposites. Crystallization studies by DSC and simultaneous SAXS/WAXD synchrotron radiation , 2009 .

[3]  Youn Jung Park,et al.  Ordered Ferroelectric PVDF−TrFE Thin Films by High Throughput Epitaxy for Nonvolatile Polymer Memory , 2008 .

[4]  Yongri Liang,et al.  Thickness-dependent crystal orientation in poly(trimethylene 2,6-naphthalate) films studied with GIWAXD and RA-FTIR methods , 2008 .

[5]  C. Chan,et al.  What Controls the Lamellar Orientation at the Surface of Polymer Films during Crystallization , 2008 .

[6]  A. Nogales,et al.  Stacking of main chain-crown ether polymers in thin films. , 2007, Langmuir : the ACS journal of surfaces and colloids.

[7]  J. Puiggalí,et al.  Isothermal crystallization of poly(glycolic acid-alt-6-hydroxyhexanoic acid) studied by DSC and real time synchrotron SAXS/WAXD , 2007 .

[8]  M. Gazzano,et al.  Neopenthyl glycol containing poly(propylene azelate)s: Synthesis and thermal properties , 2007 .

[9]  M. Gazzano,et al.  Aliphatic poly(propylene dicarboxylate)s: Effect of chain length on thermal properties and crystallization kinetics , 2007 .

[10]  S. Roth,et al.  Flow in Confined Geometry Introduced by Dewetting of Ultrathin Polystyrene Films , 2006 .

[11]  Yu Ma,et al.  Lamellar Crystal Orientations Biased by Crystallization Kinetics in Polymer Thin Films , 2006 .

[12]  Stephan Herminghaus,et al.  Dynamics and structure formation in thin polymer melt films , 2005 .

[13]  T. Ezquerra,et al.  Inhibition of the Crystallization in Nanofilms of Poly(3-hydroxybutyrate) , 2004 .

[14]  B. Nysten,et al.  Spinodal-like dewetting of thermodynamically-stable thin polymer films , 2003, The European physical journal. E, Soft matter.

[15]  D. Smilgies,et al.  Lamellar Diblock Copolymer Thin Films Investigated by Tapping Mode Atomic Force Microscopy: Molar-Mass Dependence of Surface Ordering , 2003 .

[16]  R Seemann,et al.  Dewetting patterns and molecular forces: a reconciliation. , 2001, Physical review letters.

[17]  G. Beaucage,et al.  Morphological study of HDPE blown films by SAXS, SEM and TEM: a relationship between the melt elasticity parameter and lamellae orientation , 2001 .

[18]  R. Segalman,et al.  Dynamics of Rims and the Onset of Spinodal Dewetting at Liquid/Liquid Interfaces , 1999 .

[19]  T. C. Huang,et al.  X‐ray powder diffraction analysis of silver behenate, a possible low‐angle diffraction standard , 1993 .