Synthesis and crystallization behavior of poly( l -lactide)- block -poly(ϵ-caprolactone) copolymer

Kim, Jin Kon; Park, Dong-Jin; Lee, Myung-Se; Ihn, Kyo Jin

doi:10.1016/s0032-3861(01)00217-8

Cited by 147 publications

(143 citation statements)

References 35 publications

Supporting

Mentioning

131

Contrasting

Unclassified

Order By: Relevance

“…PLLA/PCL blends were also utilized to prepare 3D nano-fibrous scaffolds by L-L TIPS from a THF solution (Zhao et al, 2004). However, PLLA with a high molecular weight could usually not be mixed with PCL, and the adhesion between PCL and PLLA became weak, resulting in poor mechanical properties (Kim et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

Microstructure and properties of nano-fibrous PCL-b-PLLA scaffolds for cartilage tissue engineering

Liu²,

Guan³

et al. 2009

eCM

View full text Add to dashboard Cite

Nano-fibrous scaffolds which could potentially mimic the architecture of extracellular matrix (ECM) have been considered a good candidate matrix for cell delivery in tissue engineering applications. In the present study, a semicrystalline diblock copolymer, poly(ε-caprolactone)-block-poly(L-lactide) (PCL-b-PLLA), was synthesized and utilized to fabricate nano-fibrous scaffolds via a thermally induced phase separation process. Uniform nano-fibrous networks were created by quenching a PCL-b-PLLA/THF homogenous solution to -20ºC or below, followed by further gelation for 2 hours due to the presence of PLLA and PCL microcrystals. However, knot-like structures as well as continuously smooth pellicles appeared among the nanofibrous network with increasing gelation temperature. DSC analysis indicated that the crystallization of PCL segments was interrupted by rigid PLLA segments, resulting in an amorphous phase at high gelation temperatures. Combining TIPS (thermally induced phase separation) with saltleaching methods, nano-fibrous architecture and interconnected pore structures (144±36 μm in diameter) with a high porosity were created for in vitro culture of chondrocytes. Specific surface area and protein adsorption on the surface of the nano-fibrous scaffold were three times higher than on the surface of the solid-walled scaffold. Chondrocytes cultured on the nano-fibrous scaffold exhibited a spherical condrocyte-like phenotype and secreted more cartilage-like extracellular matrix (ECM) than those cultured on the solid-walled scaffold. Moreover, the protein and DNA contents of cells cultured on the nanofibrous scaffold were 1.2-1.4 times higher than those on the solid-walled scaffold. Higher expression levels of collagen II and aggrecan mRNA were induced on the nanofibrous scaffold compared to on the solid-walled scaffold. These findings demonstrated that scaffolds with a nanofibrous architecture could serve as superior scaffolds for cartilage tissue engineering.

show abstract

Section: Introductionmentioning

confidence: 99%

Microstructure and properties of nano-fibrous PCL-b-PLLA scaffolds for cartilage tissue engineering

Liu²,

Guan³

et al. 2009

eCM

View full text Add to dashboard Cite

show abstract

“…Some steps such as reducing the use of plastic products and recycling the plastic waste have been taken to solve this problem. One of the feasible ways is to develop biodegradable plastics 1 .Therefore, a series of biodegradable polymers were developed in the past decades, most of which were aliphatic polyesters, such as poly(lactic acid) (PLA), poly(ε-caprolactone) (PCL), poly(3-hydroxybutyrate) (PHB), poly(butylene succinate) (PBS), poly(propylene succinate) (PPSu), poly(propylene adipate) (PPAd) , poly(ethylene succinate) (PES),and poly(propylene sebacate) (PPSe) [2][3][4][5][6][7] . Much attention is being paid to aliphatic polyesters because of their degradability 8,9 .…”

Section: Introductionmentioning

confidence: 99%

Investigations on Preparation and Characterization of Certain Copolyesters

Jayachandran¹,

Cingaram²,

Jaisankar

et al. 2016

Mat. Res.

View full text Add to dashboard Cite

In this paper, we report on the synthesis and characterization of high molecular weight copolyesters from Terephthalic acid, 1, 4 butane diol and Succinic acid /Sebacic acid through a two step process of melt polycondensation using titanium tetra butoxide as catalyst. The synthesized aromatic-aliphatic random copolyesters were characterized by means of FTIR, 1 H NMR, 13C NMR, Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD), Gel Permeation Chromatography (GPC) and Scanning Electron Microscope (SEM) studies. The effect of copolymer composition on the physical and thermal properties as well as degradation test was investigated. The degradation test was carried out in alkali medium. The phase behaviour of the polymers was studied by differential scanning calorimetry and optical polarising microscopy. The results revealed that the newly synthesized copolyesters exhibited degradability and thermotropic liquid crystalline behaviour with nematic texture which was revealed by optical polarising microscopy. The Novelty of this work is that the glass transition temperature and melting temperature are above the room temperature for the synthesized polymers. This shows the good thermal stability which results in early processing of liquid crystalline materials.

show abstract

“…However, DSC and FT/IR results revealed that the crystallinity of PCL blocks significantly increased and simultaneously that of PE blocks decreased moderately with increasing crystallization time at the late stage. These results suggest the partial melting of PE crystals facilitated by further crystallization of PCL blocks in order to compensate the space previously occupied by amorphous PCL blocks.KEY WORDS: Crystalline-crystalline Diblock Copolymer / Isothermal Crystallization / Morphological Evolution / Crystalline-crystalline diblock copolymers show an interesting morphology formation by the interplay between two kinds of crystallization starting from the microdomain structure formed in the melt.1 There are many studies on the crystallization behavior and resulting morphology of double crystalline diblock copolymers, such as poly("-caprolactone)-blockpoly(ethylene oxide) (PCL-b-PEO), 2-11 poly(p-dioxanone)-15-17 poly(L-lactide)-block-PCL (PLLA-b-PCL), [18][19][20][21][22] and PCL-b-PE. [23][24][25][26][27] In PCL-b-PEO, both blocks have a close melting temperature T m and eventually two kinds of crystallization occur simultaneously to result in a characteristic morphology in the system.…”

mentioning

confidence: 99%

Morphological Evolution during Isothermal Crystallization Observed in a Crystalline-Crystalline Diblock Copolymer

Sakurai

Ohguma

Nojima

2008

Polym J

View full text Add to dashboard Cite

Morphological evolution during isothermal crystallization over a long time ($3 d) in a crystalline-crystalline diblock copolymer, poly("-caprolactone)-block-polyethylene (PCL-b-PE), has been investigated at various temperatures T c by SAXS, DSC, and FT/IR techniques. The crystallization temperature of PE blocks was sufficiently higher than that of PCL blocks, so that PE blocks crystallized first by quenching PCL-b-PE from a microphase-separated melt into T c followed by the crystallization of PCL blocks, and eventually PCL+PE-crystallized morphology was formed in the system. The long period L, an alternating distance of the morphology, did not change at all during isothermal crystallization after an initial increase in L by the crystallization of both blocks, indicating no apparent change in the morphology at the late stage crystallization. However, DSC and FT/IR results revealed that the crystallinity of PCL blocks significantly increased and simultaneously that of PE blocks decreased moderately with increasing crystallization time at the late stage. These results suggest the partial melting of PE crystals facilitated by further crystallization of PCL blocks in order to compensate the space previously occupied by amorphous PCL blocks.KEY WORDS: Crystalline-crystalline Diblock Copolymer / Isothermal Crystallization / Morphological Evolution / Crystalline-crystalline diblock copolymers show an interesting morphology formation by the interplay between two kinds of crystallization starting from the microdomain structure formed in the melt.1 There are many studies on the crystallization behavior and resulting morphology of double crystalline diblock copolymers, such as poly("-caprolactone)-blockpoly(ethylene oxide) (PCL-b-PEO), 2-11 poly(p-dioxanone)-15-17 poly(L-lactide)-block-PCL (PLLA-b-PCL), [18][19][20][21][22] and PCL-b-PE. [23][24][25][26][27] In PCL-b-PEO, both blocks have a close melting temperature T m and eventually two kinds of crystallization occur simultaneously to result in a characteristic morphology in the system. In other block copolymers, T m of one block is enough higher than that of the other, and consequently the higher-T m blocks crystallize first by quenching the copolymer from a microphase-separated melt into low temperatures, followed by the crystallization of lower-T m blocks starting from the crystallized solid morphology already formed in the system. In dynamic studies on the morphology formation in such systems, the early stage crystallization of higher-T m blocks and/or lower-T m blocks was mainly investigated by time-resolved small-angle X-ray scattering with synchrotron radiation (SR-SAXS), where the SAXS curves show a drastic change by the crystallization of each block.We have recently investigated the melting behavior of PCLb-PE diblocks by SR-SAXS, and found that the long period L, an alternating distance of the morphology, changed complicatedly during heating. 26 In particular, L decreased discontinuously at T m of PCL blocks (lower-T m blocks) for all PCL-b-PE copolymers investi...

show abstract

Synthesis and crystallization behavior of poly( l -lactide)- block -poly(ϵ-caprolactone) copolymer

Cited by 147 publications

References 35 publications

Microstructure and properties of nano-fibrous PCL-b-PLLA scaffolds for cartilage tissue engineering

Microstructure and properties of nano-fibrous PCL-b-PLLA scaffolds for cartilage tissue engineering

Investigations on Preparation and Characterization of Certain Copolyesters

Morphological Evolution during Isothermal Crystallization Observed in a Crystalline-Crystalline Diblock Copolymer

Contact Info

Product

Resources

About