Crystalline Structure of Poly(hexamethylene adipate). Study on the Morphology and the Enzymatic Degradation of Single Crystals
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- 作者：Sebastià ; Gestí ; Ahmed Almontassir ; Marí ; a Teresa Casas ; and Jordi Puiggalí
- 刊名：Biomacromolecules
- 出版年：2006
- 出版时间：March 2006
- 年：2006
- 卷：7
- 期：3
- 页码：799 - 808
- 全文大小：1728K
- 年卷期：v.7,no.3(March 2006)
- ISSN：1526-4602
文摘
The crystalline structure of polyester 6 6 was studied by means of X-ray and electron diffraction and real-spaceelectron microscopy. An orthorhombic unit cell containing eight chain segments with a quasi planar zigzagconformation was derived. The chain axis projection could be defined by a small rectangular cell containing onlytwo molecular segments. Simulation of electron diffraction patterns indicates that molecular segments were arrangedwith azimuthal angles close to ±46
. X-ray diffraction patterns suggested that the large dimensions of the unitcell were a consequence of a slight shift between neighboring chains that improved the electrostatic interactions.Chain-folded lamellar crystals were obtained by isothermal crystallization of dilute n-hexanol or n-octanol solutions.The crystalline habit was studied, and the influence of temperature was evaluated. A regular folding surface wasobserved by using polyethylene decoration techniques. Lamellar crystals were easily degraded with differentlipases. A preferential enzymatic attack was, in some cases, observed to occur in the crystal edges, giving rise tohighly irregular borders with a fringed texture.
. X-ray diffraction patterns suggested that the large dimensions of the unitcell were a consequence of a slight shift between neighboring chains that improved the electrostatic interactions.Chain-folded lamellar crystals were obtained by isothermal crystallization of dilute n-hexanol or n-octanol solutions.The crystalline habit was studied, and the influence of temperature was evaluated. A regular folding surface wasobserved by using polyethylene decoration techniques. Lamellar crystals were easily degraded with differentlipases. A preferential enzymatic attack was, in some cases, observed to occur in the crystal edges, giving rise tohighly irregular borders with a fringed texture.