Assessing the Degradation Profile of Functional Aliphatic Polyesters with Precise Control of the Degradation Products

Höglund, Anders; Målberg, Sofia; Albertsson, Ann‐Christine

doi:10.1002/mabi.201100288

Cited by 15 publications

(10 citation statements)

References 33 publications

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“…PLLA-PDL-PLLA and PLLA-PDXO-PLLA, which had lower C/O ratios, displayed degradation rates of 3.0 Â 10 À3 (days À1 ) and 1.7 Â 10 À2 (days À1 ), respectively. The hydrolytic behavior obtained for a similar copolymer systems based on PLLA-PBM (C/O ¼ 1.6) was compared to our prediction contour plot and was confirmed to undergo a 50% decrease in molar mass over a period of approximately 30 days [49], which confirmed the effectiveness of our prediction model for assessing the hydrolysis rates of block copolymer systems. Material properties and degradation products affected during hydrolysis such as molar mass loss, mass loss, block compositional changes, pH of the degradation milieu and the degrees of crystallinity of the semicrystalline side-blocks were then analyzed.…”

Section: Block Copolymers With Forecasted Hydrolysissupporting

confidence: 67%

Forecasting linear aliphatic copolyester degradation through modular block design

Arias

Olsén

Odelius

et al. 2016

Polymer Degradation and Stability

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a b s t r a c tThe development of efficient methods to predict the degradation of renewable polymeric materials is continuously sought in the field of polymer science. Herein, we present a modular build-up approach to create polyester-based materials with forecasted degradation rates based on the hydrolysis of the constituent polymer blocks. This involved the strategic combination of critical factors affecting polyester hydrolysis, i.e. hydrophobicity and degree of crystallinity. The starting point of this method was a toolbox of polymers with different hydrophobicities and degrees of crystallinity, as well as an understanding of their inherent differences in hydrolysis rate. Knowledge of the hydrolysis of each polymer block module enabled the prediction of the overall degradation behavior of the constructed copolymers. Taking advantage of the primary factors that affect polymer degradation, block copolymers could be independently designed to incorporate soft or rigid and faster or slower degradation properties. This approach generated a shift for how molecular design can be used to predict the degradation behavior of intended materials for different applications.

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Section: Block Copolymers With Forecasted Hydrolysissupporting

confidence: 67%

Forecasting linear aliphatic copolyester degradation through modular block design

Arias

Olsén

Odelius

et al. 2016

Polymer Degradation and Stability

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“…Many authors have studied PLLA degradation, in relation to such aspects as pH, crystallinity, and the % of absorbed water, among others . However, there are relatively few results on the effects of nanoparticles such as nanohydroxyapatite (nHA) on PLLA aging and degradation behavior .…”

Section: Introductionmentioning

confidence: 99%

In vitro degradation of PLLA/nHA composite scaffolds

et al. 2013

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Porous Poly‐l‐lactide (PLLA) scaffolds and PLLA/nanohydroxyapatite (nHA) composite scaffolds with interconnected pore networks and a porosity of over 90% were fabricated with lyophilization techniques. In this study, the degradation behavior of PLLA and PLLA/nHA composite scaffolds is investigated over 8 weeks in phosphate buffer solution at 37°C. Thermal analysis using differential scanning calorimetry (DSC) showed that the percent crystallinity of all the samples increased by approximately 10%, which represents a considerable increase in the glass transition temperature. The melting range enthalpy of the scaffolds did not change to lower temperatures as would be expected. The spectroscopic analysis performed by Fourier transform infrared spectroscopy suggested that nHA particles should not appreciably affect the absorbance pattern when evenly mixed with the PLLA. This is consistent with the analysis of the scaffold microstructure and morphology with scanning electron microscopy, which drew a low content of nHA with no significant effect on solvent crystallization or pore structure. The compressive modulus and the yield strength of the scaffolds were investigated in conjunction with the study of their degradation rates. In comparison with the mechanical properties of the PLLA scaffolds, which remained largely unchanged, those of the PLLA/nHA composite scaffolds decreased as the degradation progressed. POLYM. ENG. SCI., 54:2571–2578, 2014. © 2013 Society of Plastics Engineers

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“…24,25 Degradable block copolymers have attracted much attention in the scientific community because of the wide range of possibilities to create new materials with tailored mechanical properties and degradability. [26][27][28][29][30][31][32][33][34] In terms of degradation, past research has mostly focused on how the degradation path is altered as a function of bulk modifications in the material. 28,[35][36][37][38][39][40][41] However, we have previously shown that it is also possible to tailor the degradation path of PLLA-based materials by means of specific interactions between polymer pairs responsible for blend compatibility.…”

Section: Introductionmentioning

confidence: 99%

“…[26][27][28][29][30][31][32][33][34] In terms of degradation, past research has mostly focused on how the degradation path is altered as a function of bulk modifications in the material. 28,[35][36][37][38][39][40][41] However, we have previously shown that it is also possible to tailor the degradation path of PLLA-based materials by means of specific interactions between polymer pairs responsible for blend compatibility. 41,42 In light of this finding, to expand this concept into the design of aliphatic block copolymers, the effect of compatibility between the comonomers in the composition on the degradation path of the material needs to be understood.…”

Section: Introductionmentioning

confidence: 99%

Selective degradation in aliphatic block copolyesters by controlling the heterogeneity of the amorphous phase

et al. 2015

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Controlling the course of the degradation of aliphatic polyesters is a key question when designing new degradable materials. It is shown herein that it is possible to predetermine the degradation path of aliphatic block copolyesters by controlling the heterogeneity of the amorphous phase, which in turn regulates the availability of the hydrolyzable groups in the polyester backbone. To demonstrate these processes, we synthesized a set of degradable materials based on poly(L-lactide) (PLLA), poly(ε-decalactone) (PεDL) and poly(ε-caprolactone) (PCL) with varying compositions. The materials were subjected to hydrolysis for a six months period. The materials composed of PLLA and PεDL exhibited a heterogeneous amorphous phase, whereas the materials composed of PCL and PεDL presented a more homogeneous phase. The kinetics of the degradation indicated that the slowest degradation rate was observed for the more homogeneous compositions. The degradation path of the heterogeneous amorphous phase materials was driven by a random chain scission process, whereas the more homogeneous composition presented a degradation path driven by a more selective chain scission. The confinement of the amorphous phase by the more hydrolytically stable PεDL permitted a selective degradation of the available hydrolyzable groups. The random and more selective chain scission processes were further verified by using previously determined molecular modeling based on Monte Carlo procedures. Topographical images and thermal analyses of the materials under different degradation periods correlated with the proposed degradation paths. Detailed insights and the ability to predetermine the degradation pathways of aliphatic polyesters will continue to expand the great potential of renewable materials and their use in specific applications for a future sustainable society.

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Assessing the Degradation Profile of Functional Aliphatic Polyesters with Precise Control of the Degradation Products

Cited by 15 publications

References 33 publications

Forecasting linear aliphatic copolyester degradation through modular block design

Forecasting linear aliphatic copolyester degradation through modular block design

In vitro degradation of PLLA/nHA composite scaffolds

Selective degradation in aliphatic block copolyesters by controlling the heterogeneity of the amorphous phase

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