Differential scanning calorimetry investigation of formation of poly(ethylene glycol) hydrate with controlled freeze-thawing of aqueous protein solution

2003 ◽  
Vol 91 (3) ◽  
pp. 1626-1634 ◽  
Author(s):  
Anna Hillgren ◽  
Maggie Aldén
Keyword(s):  
Differential Scanning Calorimetry ◽  
Ethylene Glycol ◽  
Poly Ethylene Glycol ◽  
Protein Solution ◽  
Scanning Calorimetry ◽  
Poly Ethylene

Gelation Crystallization of Poly(L-Lactide) in Solvents of Varying Molecular Size

2007 ◽  
Vol 15 (5) ◽  
pp. 389-393
Author(s):  
Hong Hao ◽  
Guozheng Liang ◽  
Junmin Zhao
Keyword(s):  
Differential Scanning Calorimetry ◽  
Ethylene Glycol ◽  
Crystallization Rate ◽  
Molecular Size ◽  
Large Molecule ◽  
X Ray Diffraction ◽  
Poly Ethylene Glycol ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Poly Ethylene

The crystallization behaviour of poly(L-lactide) (PLLA) samples prepared in large-molecule solvents, such as poly(ethylene glycol) (PEG), was studied by differential scanning calorimetry (DSC) and X-ray diffraction. The results indicate that those samples recovered from large-molecule solvents exhibit higher crystallinity, non-isothermal crystallization temperature and faster crystallization rate than the ones crystallized in a small-molecule solvent. The crystallinity of samples from PLLA/PEG gel is about 73% measured by the DSC. The molar size of the solvent has a large influence on the formation of helical conformations and, thereby on the crystallization rate of PLLA in solution.

scholarly journals Tailoring Atomoxetine Release Rate from DLP 3D-Printed Tablets Using Artificial Neural Networks: Influence of Tablet Thickness and Drug Loading

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 111
Author(s):  
Gordana Stanojević ◽  
Djordje Medarević ◽  
Ivana Adamov ◽  
Nikola Pešić ◽  
Jovana Kovačević ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Release Rate ◽  
Drug Loading ◽  
Prolonged Release ◽  
Cylindrical Shape ◽  
Poly Ethylene Glycol ◽  
Scanning Calorimetry ◽  
3D Printed ◽  
Artificial Neural ◽  
Poly Ethylene

Various three-dimensional printing (3DP) technologies have been investigated so far in relation to their potential to produce customizable medicines and medical devices. The aim of this study was to examine the possibility of tailoring drug release rates from immediate to prolonged release by varying the tablet thickness and the drug loading, as well as to develop artificial neural network (ANN) predictive models for atomoxetine (ATH) release rate from DLP 3D-printed tablets. Photoreactive mixtures were comprised of poly(ethylene glycol) diacrylate (PEGDA) and poly(ethylene glycol) 400 in a constant ratio of 3:1, water, photoinitiator and ATH as a model drug whose content was varied from 5% to 20% (w/w). Designed 3D models of cylindrical shape tablets were of constant diameter, but different thickness. A series of tablets with doses ranging from 2.06 mg to 37.48 mg, exhibiting immediate- and modified-release profiles were successfully fabricated, confirming the potential of this technology in manufacturing dosage forms on demand, with the possibility to adjust the dose and release behavior by varying drug loading and dimensions of tablets. DSC (differential scanning calorimetry), XRPD (X-ray powder diffraction) and microscopic analysis showed that ATH remained in a crystalline form in tablets, while FTIR spectroscopy confirmed that no interactions occurred between ATH and polymers.

Mechanical properties and hydrolytic degradation of methoxy poly(ethylene glycol)-b-poly(DL-lactide-coglycolide- co-ε-caprolactone) diblock copolymer films

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Nongnit Morakot ◽  
Jirasak Threeprom ◽  
Yodthong Baimark
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Ethylene Glycol ◽  
Diblock Copolymers ◽  
Hydrolytic Degradation ◽  
Size Exclusion ◽  
Block Length ◽  
Poly Ethylene Glycol ◽  
Scanning Calorimetry ◽  
Poly Ethylene

AbstractBiodegradable films of methoxy poly(ethylene glycol)-b-poly(DL-lactideco- glycolide-co-ε-caprolactone) diblock copolymers (MPEG-b-PDLLGCL) were prepared by solution casting method. Effects of MPEG block length and DLL:G:CL ratio of the MPEG-b-PDLLGCL films on their mechanical properties and hydrolytic degradation were studied and discussed. It was found that the mechanical properties of films were strongly dependent on glass transition temperatures (Tg) of the diblock copolymers. The hydrolytic degradation was investigated in phosphatebuffered solution at 37°C. The degraded films were characterized using gravimetry (%water uptake and %weight loss), 1H-NMR spectroscopy, differential scanning calorimetry and size exclusion chromatography. The %weight loss of the degraded films increased and molecular weight decreased on increasing the MPEG block length and incorporating the G and CL units, according to their %water uptakes. The MPEG content of the degraded film decreased and the Tg increased with hydrolytic degradation time.

scholarly journals Polymer Electrolytes Based on Borane/Poly(ethylene glycol) Methyl Ether for Lithium Batteries

2017 ◽  
Vol 2017 ◽  
pp. 1-6
Author(s):  
Ali Murat Soydan ◽  
Recep Akdeniz
Keyword(s):  
Ethylene Glycol ◽  
Methyl Ether ◽  
Polymer Electrolytes ◽  
Lithium Ion ◽  
Poly Ethylene Glycol ◽  
Scanning Calorimetry ◽  
Molar Ratios ◽  
Poly Ethylene ◽  
Chain Lengths ◽  
Glycol Methyl Ether

This work presents a different approach to preparing polymer electrolytes having borate ester groups for lithium ion batteries. The polymers were synthesized by reaction between poly(ethylene glycol) methyl ether (PEGME) and BH3-THF complex. Molecular weight of PEGMEs was changed with different chain lengths. Then the polymer electrolytes comprising boron were prepared by doping of the matrices with CF3SO3Li at various molar ratios with respect to EO to Li and they are abbreviated as PEGMEX-B-Y. The identification of the PEGME-borate esters was carried out by FTIR and 1H NMR spectroscopy. Thermal properties of these electrolytes were investigated via thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The ionic conductivity of these novel polymer electrolytes was studied by dielectric-impedance spectroscopy. Lithium ion conductivity of these electrolytes was changed by the length of PEGME as well as the doping ratios. They exhibit approximate conductivities of 10−4 S·cm−1 at 30°C and 10−3 S·cm−1 at 100°C.

Application of ionic liquid [bmim]PF6 as green plasticizer for poly(L-lactide)

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Puyu Zhang ◽  
Lichao Peng ◽  
Wenbin Li
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Ionic Liquid ◽  
Glass Transition ◽  
Transition Temperature ◽  
Poly Ethylene Glycol ◽  
Scanning Calorimetry ◽  
Poly Ethylene ◽  
Thermal Stability Of ◽  
Better Than

AbstractIonic liquid [bmim]PF6 (1-butyl-3-methylimidazolium hexafluoro phosphate) was synthesized and characterized. It was used as the plasticizer for poly(L-lactide) (PLLA). The glass transition temperature (Tg) and the thermal stability of the plasticized PLLA samples were measured by thermogravimetry (TG) and differential scanning calorimetry (DSC). Compared with poly(ethylene glycol) having Mw of 300 g/mol (PEG300), TG results showed that the thermal stability of PLLA plasticized with ionic liquid was better than that of PLLA plasticized with PEG300. The Tg of plasticized PLLA decrease with increasing the content of ionic liquid [bmim]PF6 from 2 wt.% to 10 wt.%. The Tg of PLLA can be reduced to 40°C when the content of ionic liquid [bmim]PF6 was 10 wt.%. The materials of PLLA with plasticizer were also investigated using polarizing microscope (POM), the results of which indicate that the movements of PLLA chains were improved when ionic liquid plasticizer was used.

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