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Your search keyword '"Poly(epsilon-caprolactone)"' showing total 3 results
Start Over Descriptor "Poly(epsilon-caprolactone)" Journal polymer
3 results on '"Poly(epsilon-caprolactone)"'

1. Solvent evaporation induced fabrication of porous polycaprolactone scaffold via low-temperature 3D printing for regeneration medicine researches.

Author

Xiao, Xiong, Jiang, Xia, Yang, Shaojie, Lu, Zuyan, Niu, Chuan, Xu, Yue, Huang, Ziwei, Kang, Y. James, and Feng, Li

Subjects
*POLYCAPROLACTONE, *THREE-dimensional printing, *MEDICAL research, *POROUS polymers, *POLYMER solutions, *PRINTING ink
Abstract

Liquid deposition modeling (LDM) is an evolving three-dimensional (3D) printing approach that mainly utilizes polymer solutions to enable the fabrication of biomedical scaffolds under mild conditions. A deep understanding of the rheological properties of polymer printing inks and the features of yielded scaffolds are critical for a successful LDM based fabrication of biomedical scaffolds. In this work, polymer printing inks comprised of Poly(epsilon-caprolactone) (PCL), sodium chloride (NaCl), and trichloromethane (CHCl 3) were prepared. The rheological properties, including extrudability (shear stress, viscosity, and shear-thinning) and self-supporting ability (viscosity) of all printing inks were analyzed. Then printing performance was evaluated by measuring the die-swell ratio, 2D, and 3D printing fidelities. Finally, a series of porous PCL scaffolds were fabricated using printing inks comprised of different feed ratios (20:80, 40:60, 50:50, 60:40, and 80:20) of NaCl to PCL, and the porosity, mechanical properties, degradation behaviors, and biocompatibility were discussed. The results suggested that the printing ink formulation is greatly affected the printing performances. The increasing NaCl content in printing inks reduced shear force for extrusion, enhanced the shear-thinning behavior, increased the curing time. The dropping temperature and solvent evaporation both enhanced the self-supporting ability of the printing inks and solvent evaporation is a critical factor for the curing of the printing inks. The further evaluation demonstrated that the obtained fabricated porous PCL scaffolds were endowed with good biocompatibility and controllable porosity, mechanical features, and in vitro degradation behavior related to the NaCl content in the printing inks. This study built a fabricating method of porous polymer scaffolds by 3D printing at low temperatures for regeneration medicine researches. Image 1 • A 3D printing approach at 37 °C was established to fabricate porous PCL scaffolds for tissue regeneration studies. [ABSTRACT FROM AUTHOR]

Published
2021
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2. Morphology in binary blends of poly(vinyl methyl ether) and epsilon-caprolactone-trimethylene carbonate diblock copolymer

Author

E.J.F. Bögels, M.C. Luyten, B. E. Komanschek, G. ten Brinke, Wim Bras, Anthony J. Ryan, and G.O.R. Alberda van Ekenstein

Subjects
Materials science, MISCIBILITY, Polymers and Plastics, crystallization, block copolymer, CRYSTALLINE BLOCK-COPOLYMERS, Miscibility, law.invention, chemistry.chemical_compound, Differential scanning calorimetry, POLYMER BLENDS, PHASE-EQUILIBRIA, law, Polymer chemistry, Materials Chemistry, Copolymer, Lamellar structure, Crystallization, KINETICS, HOMOPOLYMER, Small-angle X-ray scattering, microphase separation, Organic Chemistry, POLY(EPSILON-CAPROLACTONE), MIXTURES, blend, Chemical engineering, chemistry, X-RAY, Polymer blend, Trimethylene carbonate
Abstract

The morphology of symmetric diblock copolymer of epsilon-caprolactone (PCL) and trimethylene carbonate (PTMC), in blends with poly(vinyl methyl ether) (PVME) is investigated with (modulated) differential scanning calorimetry (d.s.c.), time resolved small angle (SAXS) and wide angle (WAXS) X-ray spectroscopy and optical microscopy. In the melt the crystallizable block PCL is immiscible with the amorphous PTMC block. PCL is melt miscible with PVME, whereas PTMC and PVME are immiscible. Despite the much higher molecular weight of PVME, the favourable interaction between PVME and PCL results in a microphase separated morphology with PVME residing inside the PCL domains, In the melt, PVME is for up to 20 wt%, almost homogeneously mixed with PCL. Above 20 wt%, PVME partly segregates inside the PCL domains. In all cases, PCL starts to crystallize from a microphase separated melt. During the crystallization a characteristic small angle scattering peak together with the corresponding wide angle peaks develops. The long period of the crystalline morphology increases as a function of the amount of PVME. (C) 1997 Elsevier Science Ltd.

Published
1997

3. Crosslinked poly(L-lactide) and poly(epsilon-caprolactone)

Subjects
ACID), poly(epsilon-caprolactone), GLASS-TRANSITION TEMPERATURE, technology, industry, and agriculture, macromolecular substances, COPOLYMERS, IRRADIATION, LACTIDE, STRENGTH, MORPHOLOGY, crosslinking, POLYMERS, poly(L-lactide), FIBERS
Abstract

Several methods of introducing crosslinks into poly(L-lactide) (PLLA) were studied. Electron beam irradiation was not effective in crosslinking PLLA, and, moreover, caused severe polymer degradation and embrittlement of the material. Peroxide crosslinking of PLLA with dicumyl peroxide (DCP), however, resulted in gelation. At high peroxide concentrations (13-25 wt%) and high curing temperatures (192 degrees C), a gel fraction equal to 1 could be determined gravimetrically. Peroxide crosslinking with DCP caused chemical modification of the PLLA polymer chain, with the decomposition products having a plasticizing effect on the resulting network. For the in situ crosslinking, a tetrafunctional monomer, 5,5'-bis(oxepane-2-one) (5,5'-BO), was synthesized and used in the copolymerization with epsilon-caprolactone and L-lactide. Differential scanning calorimetry (d.s.c.) and swelling experiments showed that network formation did take place. A pronounced difference in reactivity between the L-lactide and the 5,5'-BO crosslinker was observed, with this difference in reactivity being found to be comparable to the difference between L-lactide and epsilon-caprolactone. Swelling experiments carried out with crosslinked PLLA showed that incorporation of this crosslinker into the polymer network increased at higher polymerization temperatures and longer polymerization times. When 1 mol% of crosslinker was used in the copolymerization with L-lactide, a significant increase in the impact and tensile strength was obtained when compared to uncrosslinked PLLA. Copyright (C) 1996 Elsevier Science Ltd.

Published
1996

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