Morphological development in absorbable poly(glycolide), poly(glycolide-co-lactide) and poly(glycolide-co-caprolactone) copolymers during isothermal crystallization

Wang, Z.-G.; Hsiao, Benjamin S.; Zong, Xinhua; Yeh, Fengji; Zhou, Jiangying; Dormier, Edward; Jamiolkowski, Dennis D.

doi:10.1016/s0032-3861(99)00200-1

Cited by 57 publications

(55 citation statements)

References 34 publications

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“…In contrast, for the past few years, there has been renewal of interest in aliphatic polyesters [1][2][3][4][5][6][7][8][9][10][11][12][13], for instance poly(lactic acid) (PLA), poly(glycolic acid), poly(e-caprolate), and poly(3-hydroxybutyrate), because they are highly friendly for the environment and the human body. Among of these ecological materials, poly(L-lactide) (PLLA) has drawn intensive attention for their outstanding biocompatibility and biodegradability as well as physical properties which are comparable with PS and PET [1].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of biodegradable poly(l-lactide)/layered double hydroxide nanocomposites

Chiang

2010

Composites Science and Technology

111

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Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of biodegradable poly(l-lactide)/layered double hydroxide nanocomposites

Chiang

2010

Composites Science and Technology

111

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“…¼ 2:5, 2.8 and 3.2. 19,20 The diffraction pattern of as-spun PGA fiber shows a very broad amorphous peak alone in the absence of a sharp crystalline peak, which comes from the amorphous region. Thus, this means that the crystallinity of as-spun fiber is extremely low.…”

Section: Resultsmentioning

confidence: 99%

A Study of the Relationship between the Tensile Strength and Dynamics of As-spun and Drawn Poly(glycolic acid) Fibers

Sekine

Akieda

Ando

et al. 2007

Polym J

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Higher-order structure of as-spun and highly-drawn poly(glycolic acid)(PGA) fibers has been characterized by solid-echo 1 H NMR and WAXD methods. In the observed WAXD patterns, as-spun PGA fiber shows a very broad amorphous peak and highly-drawn PGA fibers show very sharp diffraction peaks at 2 ¼ 21:9 from which the crystallinities of highly-drawn fibers with the drawing ratio( d.r. ) of 2.5, 2.8 and 3.2 are determined to be 0.50, 0.51 and 0.52, respectively. These show that the crystallinities of the PGA fibers with different drawing ratios are very close to each other. On the other hand, the observed solid-echo 1 H NMR free induction decay(FID) signals of as-spun and drawn PGA fibers show a multi-component decay consisting of the short T 2 component and the long T 2 component. From these results, the short T 2 component was assigned to the crystalline region and the immobile amorphous region, and the long T 2 component was assigned to the mobile amorphous region. It was found that the fractions of the short T 2 component and the long T 2 component of highly-drawn fibers largely depend on the drawing ratio d.r. and temperature, and that the fractions of the short T 2 component for drawn PGA fibers with d.r. of 2.5 at 120 C and 160 C are 0.85 and 0.56, respectively. Further, it was found that the fractions of the short T 2 component for the drawn fibers above 160 C are very close to the crystallinities determined by the WAXD patterns, but the fractions of the short T 2 component at 120 C are different from each other. The structural characterization was made to understand mechanical property of the drawn PGA fibers. Then, it was found that the fraction of the corresponding amorphous region is closely related to the ratio of the tensile strength after hydrolytic acceleration test to that before hydrolytic acceleration for PGA fibers.

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“…Other calorimetric studies of importance on PGA have been published by Cohn et al 8 and by Gilding and Reed. 9 More recently, Wang et al 10 published a study of the morphological development of PGA and some of its copolymers using time resolved X-ray diffraction techniques.…”

Section: Introductionmentioning

confidence: 99%

Structure development during crystallization and solid‐state processing of poly(glycolic acid)

Ward

Chivers

et al. 2008

J of Applied Polymer Sci

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DSC and time-resolved WAXS and SAXS are used to study the structure development during isothermal crystallization of poly(glycolic acid) (PGA) in the temperature range [180][181][182][183][184][185][186][187][188][189][190][191][192][193][194][195] C. It is shown that the crystallization rate increases with degree of supercooling in the temperature range of consideration. WAXS and DSC crystallinity measurements agree well and a final crystallinity of 50% is found independently of the crystallization temperature. In-situ SAXS measurements indicate that for PGA the final crystal thickness approaches a limiting value of 70 Å independent of the crystallization temperature in the range 195-180 C. The material develops a well-defined lamellar structure during crystallization at the highest crystallization temperature under study (195 C). We show that by increasing the degree of supercooling it is possible to hinder the formation of the lamellar structure and crystals, resulting in a less ordered structure. We report that PGA fibers with elastic modulus in the range 20-25 GPa can be prepared by adequate control of the structure before solid-state plastic deformation.

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Morphological development in absorbable poly(glycolide), poly(glycolide-co-lactide) and poly(glycolide-co-caprolactone) copolymers during isothermal crystallization

Cited by 57 publications

References 34 publications

Synthesis and characterization of biodegradable poly(l-lactide)/layered double hydroxide nanocomposites

Synthesis and characterization of biodegradable poly(l-lactide)/layered double hydroxide nanocomposites

A Study of the Relationship between the Tensile Strength and Dynamics of As-spun and Drawn Poly(glycolic acid) Fibers

Structure development during crystallization and solid‐state processing of poly(glycolic acid)

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