Stereocomplexed 8-armed poly(ethylene glycol)–poly(lactide) star block copolymer hydrogels: Gelation mechanism, mechanical properties and degradation behavior

Polymer ◽  
2012 ◽  
Vol 53 (14) ◽  
pp. 2809-2817 ◽  
Author(s):  
Sytze J. Buwalda ◽  
Lucia Calucci ◽  
Claudia Forte ◽  
Pieter J. Dijkstra ◽  
Jan Feijen
Keyword(s):  
Mechanical Properties ◽  
Block Copolymer ◽  
Ethylene Glycol ◽  
Degradation Behavior ◽  
Poly Ethylene Glycol ◽  
Gelation Mechanism ◽  
Star Block Copolymer ◽  
Poly Ethylene

scholarly journals Influence of Mixed Imide Composition and Thermal Annealing on Ionic Liquid Uptake and Conductivity of Polyimide-Poly(ethylene glycol) Segmented Block Copolymer Membranes

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7450
Author(s):  
Gokcen A. Ciftcioglu ◽  
Curtis W. Frank
Keyword(s):  
Mechanical Properties ◽  
Ionic Liquid ◽  
Block Copolymer ◽  
Ethylene Glycol ◽  
Young’S Modulus ◽  
Thermal Annealing ◽  
Young's Modulus ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene ◽  
The Impact

Understanding the impact of different bridging groups in the two-step polymerization of poly(ethylene glycol) (PEG)-incorporated polyimide (PI) materials is significant. It is known that the proton exchange membranes (PEMs) used in industry today can experience performance degradation under rising temperature conditions. Many efforts have been devoted to overcoming this problem by improving the physical and mechanical properties that extend the hygrothermal life of a PEM. This work examines the effect of oxygenated and fluorinated bridging anhydrides in the production of PI-PEG PEMs. It is shown that the dianhydride identity and the amount incorporated in the synthesis influences the properties of the segmented block copolymer (SBC) membranes, such as increased ionic liquid uptake (ILU), enhanced conductivity and higher Young’s modulus favoring stiffness comparable to Nafion 115, an industrial standard. Investigations on the ionic conductivity of PI-PEG membranes were carried out to determine how thermal annealing would affect the material’s performance as an ion-exchange membrane. By applying a thermal annealing process at 60 °C for one hour, the conductivities of synthesized segmented block copolymer membranes values were increased. The effect of thermal annealing on the mechanical properties was also shown for the undoped SBC via measuring the change in the Young’s modulus. These higher ILU abilities and mechanical behavior changes are thought to arise from the interaction between PEG molecules and ethylammonium nitrate (EAN) ionic liquid (IL). In addition, higher interconnected routes provide a better ion-transfer environment within the membrane. It was found that the conductivity was increased by a factor of ten for undoped and a factor of two to seven for IL-doped membranes after thermal annealing.

Synthesis of a Nanostructured Star Block Copolymer with a Cyclotriphosphazene Core

2006 ◽  
Vol 6 (11) ◽  
pp. 3446-3449
Author(s):  
Jae Kook Han ◽  
Sung Tae Kim ◽  
Hyun Jung Kim ◽  
Yong Ku Kwon
Keyword(s):  
Lactic Acid ◽  
Block Copolymer ◽  
Ethylene Glycol ◽  
Sodium Salt ◽  
Star Polymer ◽  
Poly Ethylene Glycol ◽  
Block Polymer ◽  
Star Block Copolymer ◽  
Poly Ethylene ◽  
Glycol Methyl Ether

An amphiphilic star block copolymer of poly(L-lactic acid)-b-poly(ethylene glycol) (PLLA-b-PEG) was synthesized using a hexachlorocyclotriphosphazene ring (N3P3Cl6) as a core. N3P3(OC6H4-p-CHO)6 was prepared by the reaction between the hexachlorocyclotriphosphazene core and 4-hydroxybenzaldehyde sodium salt. N3P3(OC6H4-p-CH2OH)6 was then obtained by reduction of N3P3(OC6H4-p-CHO)6. N3P3(OC6H4-p-CH2OH)6 was used as an initiator to obtain a PLLA-grafted star branched polymer by polymerizing lactide, which was then treated with succinic acid to produce a carboxylated PLLA-grafted star polymer. PEG blocks were attached to a carboxylated PLLA-grafted star polymer to produce an amphiphilic PLLA-b-PEG-grafted star block polymer by additional esterification with poly(ethylene glycol methyl ether).

scholarly journals Controlling surface chemistry and mechanical properties of metal ionogels through Lewis acidity and basicity

2021 ◽  
Vol 9 (8) ◽  
pp. 4679-4686
Author(s):  
Coby J. Clarke ◽  
Richard P. Matthews ◽  
Alex P. S. Brogan ◽  
Jason P. Hallett
Keyword(s):  
Mechanical Properties ◽  
Ionic Liquids ◽  
Ethylene Glycol ◽  
Surface Chemistry ◽  
Lewis Acidity ◽  
Metal Species ◽  
Poly Ethylene Glycol ◽  
Acidity And Basicity ◽  
Poly Ethylene

Gels prepared from metal containing ionic liquids with cross-linked poly(ethylene glycol) have surface compositions and mechanical properties that can be controlled by Lewis basicity and acidity of the metal species.

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