Irradiation of poly(<scp>l</scp>-lactide) biopolymer reinforced with functionalized MWCNTs

Chakoli, Ali Nabipour; He, Jinmei; Chayjan, Maryam Amirian; Huang, Yudong; Zhang, Baode

doi:10.1039/c5ra08319b

Cited by 13 publications

(7 citation statements)

References 18 publications

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“…Several procedures can be employed for sterilization of PLA or PTMC polymers, such as sterilization with ethylene oxide gas [26], low-temperature plasma, injection molding process, steam [27,28]. On the other hand, radiation processing and the commercially dominating sterilization process by high-energy radiation have been reported for modification and sterilization of PLA [29,30,31] and poly( d -lactic acid) (PDLA)-based composite materials [32], yet with severe restrictions. Because of high efficiency, excellent penetration characteristics and financial benefits of using ionizing radiation, radiation sterilization technique is widely applicable and eliminates problems which may appear with other sterilization methods, such as for instance high temperature, penetration of ethylene oxide gas or hydrogen peroxide (for cold plasma sterilization method), toxic residuals and need for quarantine period, surface chemistry change, or non-uniformity of sterilization.…”

Section: Introductionmentioning

confidence: 99%

On the Mechanisms of the Effects of Ionizing Radiation on Diblock and Random Copolymers of Poly(Lactic Acid) and Poly(Trimethylene Carbonate)

et al. 2018

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This article demonstrates that ionizing radiation induces simultaneous crosslinking and scission in poly(trimethylene carbonate-co-d-lactide) diblock and random copolymers. Copolymer films were electron-beam (EB) irradiated up to 300 kGy under anaerobic conditions and subsequently examined by evaluation of their structure (FT-IR, NMR), molecular weight, intrinsic viscosities, and thermal properties. Radiation chemistry of the copolymers is strongly influenced by the content of ester linkages of the lactide component. At low lactide content, crosslinking reaction is the dominant one; however, as the lactide ratio increases, the ester linkages scission becomes more competent and exceeds the crosslinking. Electron paramagnetic resonance (EPR) measurements indicate that higher content of amorphous carbonate units in copolymers leads to a reduction in free radical yield and faster radical decay as compared to lactide-rich compositions. The domination of scission of ester bonds was confirmed by identifying the radiolytically produced alkoxyl and acetyl radicals, the latter being more stable due to its conjugated structure.

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Section: Introductionmentioning

confidence: 99%

On the Mechanisms of the Effects of Ionizing Radiation on Diblock and Random Copolymers of Poly(Lactic Acid) and Poly(Trimethylene Carbonate)

et al. 2018

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“…In another study, film drying at 313 K under vacuum for 2 days, however, was not successful to remove the chloroform and elongation of neat PLLA was found as 158%. 48 Heat was also not applied to the prepared films in this study in order to preserve the thermal history of the samples. On the other hand, elongation at break decreased from 290% to 92.0% and 82.7% when MPOSS and IPOSS were incorporated into the polymer matrix, respectively.…”

Section: Industrial and Engineering Chemistry Researchmentioning

confidence: 99%

Highly Crystalline Poly(l-lactic acid) Porous Films Prepared with CO₂-philic, Hybrid, Liquid Cell Nucleators

Culhacioglu

Hasırcı

Dilek

2019

Ind. Eng. Chem. Res.

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Supercritical CO2 (scCO2) foaming of poly(l-lactic acid) composite films with liquid polyhedral oligomeric silsesquioxanes (PlLA-POSS) was carried out to obtain polymer matrices for drug delivery applications. Highly crystalline (>45%) PlLA generally requires high supercritical processing (saturation) temperatures close to its melting temperature (∼450 K) and pressures about or over 20 MPa for foaming with scCO2. To decrease the saturation temperature and obtain ductile PlLA films with uniform and homogeneous porosity, we used two different, novel CO2-philic organic–inorganic hybrid liquid POSS as cell nucleators. The solvent-casting of the polymer with these additives resulted in porous thin films. ScCO2 processing at 313 K and 21 MPa increased the pore density and enhanced the mechanical and thermal properties such as elastic modulus and T g of the highly crystalline PlLA porous films. ScCO2 processing led to the extraction of the cell nucleators, allowing the recovery of these additives from the porous films. Drug release studies with a model antibiotic (Ceftriaxone Sodium) showed that the porous films exhibit burst release characteristics, which is suitable for local antibiotic applications.

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“…The chain stiffness in amorphous phase of PLLA can also increase due to the van der Walls force and the homogenous dispersion of func.MWCNTs. In addition, the crystallinity of PLLA could be increased due to func.MWCNTs as heterogeneous nucleation points [19,28].…”

Section: Figurementioning

confidence: 99%

Poly(L-Lactide) Bionanocomposites

Chakoli¹

2019

Peptide Synthesis

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A variety of natural, synthetic, and biosynthetic polymers such as poly(L-lactide), polyhydroxyalkanoate, and poly(ε-caprolactone) are biocompatible and environmentally degradable. Biodegradability can therefore be engineered into polymers by the judicious addition of chemical linkages such as anhydride, ester, or amide bonds, among others. Poly(L-lactide) (PLLA) has attracted increasing attention due to the combination of its bioresorbability, biodegradability, biocompatibility, and shape memory effect. It has been widely applied to biomedical fields such as bone screws, surgical sutures, tissue engineering, and controlled drug delivery. Nevertheless, the PLLA is weaker than that of natural cortical bones in mechanical strength. Additionally, the ability of PLLA in cell attachment and bioactivity are weak due to its hydrophobic properties. In order to overcome the unsuitable properties of PLLA, various techniques have already been applied to modify the physical and mechanical properties of PLLA. The most significant method is to introduce some various kinds of fillers into PLLA matrix to provide reinforcing filler/PLLA composites, such as hydroxyapatite (HA), b-tricalcium phosphate, bioglass, silica gel, amorphous carbon, carbon nanotubes (CNTs), and so on.

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Irradiation of poly(l-lactide) biopolymer reinforced with functionalized MWCNTs

Abstract: The γirradiation increases the modulus and strength, decreases the melting point of poly(l-lactide) during sterilization. The functionalized carbon nanotubes accelerate the irradiation effect on mechanical and thermal properties of poly(l-lactide).

Cited by 13 publications

References 18 publications

On the Mechanisms of the Effects of Ionizing Radiation on Diblock and Random Copolymers of Poly(Lactic Acid) and Poly(Trimethylene Carbonate)

On the Mechanisms of the Effects of Ionizing Radiation on Diblock and Random Copolymers of Poly(Lactic Acid) and Poly(Trimethylene Carbonate)

Highly Crystalline Poly(l-lactic acid) Porous Films Prepared with CO₂-philic, Hybrid, Liquid Cell Nucleators

Poly(L-Lactide) Bionanocomposites

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Irradiation of poly(l-lactide) biopolymer reinforced with functionalized MWCNTs

Abstract: The γirradiation increases the modulus and strength, decreases the melting point of poly(l-lactide) during sterilization. The functionalized carbon nanotubes accelerate the irradiation effect on mechanical and thermal properties of poly(l-lactide).

Cited by 13 publications

References 18 publications

On the Mechanisms of the Effects of Ionizing Radiation on Diblock and Random Copolymers of Poly(Lactic Acid) and Poly(Trimethylene Carbonate)

On the Mechanisms of the Effects of Ionizing Radiation on Diblock and Random Copolymers of Poly(Lactic Acid) and Poly(Trimethylene Carbonate)

Highly Crystalline Poly(l-lactic acid) Porous Films Prepared with CO2-philic, Hybrid, Liquid Cell Nucleators

Poly(L-Lactide) Bionanocomposites

Contact Info

Product

Resources

About

Highly Crystalline Poly(l-lactic acid) Porous Films Prepared with CO₂-philic, Hybrid, Liquid Cell Nucleators