Resorbable materials of poly(<scp>L</scp>‐lactide). II. Fibers spun from solutions of poly(<scp>L</scp>‐lactide) in good solvents

Gogolewski, Sylwester; Pennings, A. J.

doi:10.1002/app.1983.070280312

Cited by 108 publications

(46 citation statements)

References 15 publications

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“…15 ) The degree of crystallinity was calculated to be ca. 50% based on the theoretical pure PLLA, 16 which is in the almost same ranges compared to those of homo PLLAs prepared by normal solution polymerization. 17 This high crystallinity might be resulted from phase-segregated morphology of the prepared block copolymer, which enhances the crystallization of PLLA block by flexible and mobile PTMC segments with low T g .…”

Section: Thermal Propertiesmentioning

confidence: 68%

Preparation and Properties of Poly(l-lactide)-block-poly(trimethylenecarbonate) as Biodegradable Thermoplastic Elastomer

Kim

Lee

2002

Polym J

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ABSTRACT:Biodegradable ABA triblock copolymers of L-lactide and trimethylene carbonate with given compositions were prepared and chain-extended to produce high molecular weight polymer. The polymers were semicrystalline, and exhibited well microphase-segregated morphology with one crystalline poly(L-lactide) (PLLA) and the other soft and amorphous poly(trimethylene carbonate) (PTMC) block segments. The polymers could be cast into flexible and tough film, reversibly stretchable with elongation up to about 300%. This material may provide a novel thermoplastic elastomer possessing desirable properties including biodegradability, biocompatibility and good mechanical properties including two-phase morphology. Also a preliminary result on the hydrolytic degradation behavior was discussed.KEY WORDS Poly(L-lactide) (PLLA) / Poly(trimethylene carbonate) (PTMC) / Block Copolymer / Biodegradable / Thermoplastic Elastomer /

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Section: Thermal Propertiesmentioning

confidence: 68%

Preparation and Properties of Poly(l-lactide)-block-poly(trimethylenecarbonate) as Biodegradable Thermoplastic Elastomer

Kim

Lee

2002

Polym J

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“…Many previous studies on the degradation of PLLA or poly(DL-lactic acid) involved specimens in the form of films, foams, rods, or plates. [5][6][7][8][9][10][11] PLLA fibers can be produced by means of melt spinning 12,13 or solution spinning 14,15 for use as sutures 16,17 and in ligament reconstruction. 18 The in vitro degradation of PLLA fibers in phosphate buffered saline (PBS, pH 7.4) was investigated previously.…”

Section: Introductionmentioning

confidence: 99%

In vitro degradation of poly(L‐ lactic acid) fibers in phosphate buffered saline

Yuan

Mak

Yao

2002

J of Applied Polymer Sci

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ABSTRACT:In vitro degradation of poly(L-lactic acid) (PLLA) fibers was studied by incubating the fibers in phosphate buffered saline (pH 7.4) at 37°C for 35-45 weeks. Three kinds of PLLA fibers with different diameters and different initial viscosityaverage molecular weights were tested. The viscosity-average molecular weight, crystallinity, morphology, and tensile properties of the PLLA fibers were monitored along the degradation period. The results showed that the viscosity-average molecular weight of the PLLA fibers dropped gradually during the in vitro degradation period, and it decreased by 40 -60% at the end of the experimental period. The crystallinity of the PLLA fibers measured by differential scanning calorimetry was noted to increase slightly. The tensile moduli, ultimate strengths, and elongations of the fibers did not exhibit significant changes in 35 weeks of degradation but PLLA fibers with a smaller diameter of 113 m showed significant decreases in their ultimate strengths with respect to the initial value after 35-45 weeks of degradation. Microcracks appeared on part of the fiber surfaces, which might ultimately lead to the decrease of the mechanical strength of the PLLA fibers. The spotty defects reported in this study apparently did not affect the mechanical properties of the fibers. The results suggested that the tensile properties of the PLLA fibers were mechanically stable in 35 weeks of in vitro degradation, although their molecular weights decreased remarkably and obvious spotty defects appeared on their surfaces.

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“…PLLA has been widely studied for biomedical applications, particularly those that demand good mechanical properties for surgical sutures and devices for internal bone fixation [6][7][8][9][10]. However, homopoly(L-LA) has been reported to exhibit relatively poor biodegradability.…”

Section: Introductionmentioning

confidence: 99%

Comparison of Sm complexes with Sn compounds for syntheses of copolymers composed of lactide and cyclic carbonates and their biodegradabilities

Nakayama

Yasuda

Yamamoto

et al. 2005

Reactive and Functional Polymers

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The comparison of organolanthanide complexes, (C 5 Me 5 ) 2 SmMe(THF) (Sm1) and [(C 5 Me 5 ) 2 Sm] 2 (PhC=C=C= CPh) (Sm2), with tin compounds, Bu 2 Sn(OMe) 2 (Sn1) and Bu 2 Sn(OCH 2 CH 2 CH 2 O) (Sn2), in the preparation of random, diblock, and triblock copolymers composed of L-lactide (L-LA) or D,L-LA and cyclic carbonates, trimethylene carbonate (TMC) or 2,2-dimethyltrimethylene carbonate (DTC) is reported. The biodegradabilities of the resulting copolymers with proteinase K and a compost were examined. The copolymerization of L-LA with cyclic carbonates by Sm1 or Sm2 afforded copolymers with relatively low melting points (<160 °C) due to the accompanying epimerization in comparison with those obtained with Sn1 or Sn2. In the degradation of the polymers with a compost, the copolymers based on D,L-LA were more degradable than those based on L-LA. On the other hand, the effect of the incorporated cyclic carbonate on its degradability was more drastic in the copolymers based on L-LA than those in the copolymers based on D,L-LA. The introduction of only a small amount of the cyclic carbonates into PLLA significantly enhanced the degradability of PLLA with a compost or proteinase K. In the enzymatic degradation of L-LA-containing polymers, the copolymerization of L-LA with TMC was also quite effective to improve the degradability of PLLA. Triblock copolymerization tends to be effective to enhance the degradability of PLLA.

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Resorbable materials of poly(L‐lactide). II. Fibers spun from solutions of poly(L‐lactide) in good solvents

Cited by 108 publications

References 15 publications

Preparation and Properties of Poly(l-lactide)-block-poly(trimethylenecarbonate) as Biodegradable Thermoplastic Elastomer

Preparation and Properties of Poly(l-lactide)-block-poly(trimethylenecarbonate) as Biodegradable Thermoplastic Elastomer

In vitro degradation of poly(L‐ lactic acid) fibers in phosphate buffered saline

Comparison of Sm complexes with Sn compounds for syntheses of copolymers composed of lactide and cyclic carbonates and their biodegradabilities

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