Morphology and structure of poly( p-dioxanone)

• Published in: European polymer journal Vol. 43; no. 11; pp. 4662 - 4674
• Main Authors: Gestí, Sebastià, Lotz, Bernard, Casas, María Teresa, Alemán, Carlos, Puiggali, Jordi
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-11-2007; Elsevier
• Subjects: Applied sciences; Crystal morphology; Electron microscopy; Exact sciences and technology; Lamella; Molecular conformation; Organic polymers; Physicochemistry of polymers; Poly( p-dioxanone); Properties and characterization; Pseudomonas cepacia; Structure, morphology and analysis; Molecular conformation; Lamella; Crystal morphology; Electron microscopy; Poly( p-dioxanone); Poly(p-dioxanone); Experimental study; Lattice parameters; Lactone polymer; Single crystal; Structure processing relationship; Spherulites; Aliphatic polymer; Solution crystallization; Isothermal crystallization; Conformation; Crystalline structure
• ISSN: 0014-3057; 1873-1945
• DOI: 10.1016/j.eurpolymj.2007.08.007

The morphology of solution grown single crystals of poly(
p-dioxanone) was investigated. Different crystallization conditions (solvent, precipitant agent and temperature) were tested. Dendritic growth, screw dislocations and striations were observed. Crystals usually exhibited a lozenge morphology, whose apex angle changed with the crystallization conditions. In all cases, however, a single crystal electron diffraction pattern was recorded. Spherulitic morphologies were obtained by evaporation of formic acid solutions. Lamellae gave rise to well resolved electron diffraction patterns that allowed determination of the main packing characteristics. Patterns of tilted specimens helped establish an orthorhombic unit cell, whose parameters indicate a deviation from the all
trans molecular conformation. Quantum mechanical calculations were performed on small model compounds to study the conformational preferences. Simulated diffraction patterns were consistent with a unit cell containing four repeat units and a
P2
12
12
1
space group. Molecular packing suggests the existence of different kinds of folds for an assumed adjacent reentry. Polyethylene decoration hardly highlighted a crystal sectorization. Also enzymatic degradation of lamellar crystals was evaluated by using a
Pseudomonas cepacia lipase.