Structure and properties of hydrophilic polymers and their gels. XII. Relaxation behaviour of the system poly(ethylene glycol monomethacrylate)-water below the glass transition temperature

1969 ◽  
Vol 34 (2) ◽  
pp. 545-552 ◽  
Author(s):  
V. Barešová
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Ethylene Glycol ◽  
Hydrophilic Polymers ◽  
Relaxation Behaviour ◽  
Structure And Properties ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene

scholarly journals Thermal and Dynamic Mechanical Analyses of Poly(Lactic Acid)/Poly(Ethylene Glycol) Blends

2018 ◽  
Vol 1 (1) ◽  
pp. 526-535
Author(s):  
Benaniba Mohamed Tahar ◽  
Aouachria Kamira
Keyword(s):  
Lactic Acid ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Ethylene Glycol ◽  
Poly Lactic Acid ◽  
Poly Ethylene Glycol ◽  
Scanning Calorimetry ◽  
Dynamic Mechanical ◽  
Poly Ethylene

Blends of poly(lactic acid) (PLA) and poly(ethylene glycol) (PEG) with various contents (0, 5, 10, 15, 20 and 30 weight %) and with different molecular weights (M¯w = 1000, 4000 and 6000 g/mol), called respectively PEG1, PEG2, and PEG3 were prepared by melt blending. Since glass transition temperature (Tg), T? and loss factor (tan ?) are relevant indicators of polymer chain mobility, plasticization has been studied by dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). Low molecular weight (LMW) PEG enable increased miscibility with PLA and more efficient reduction of glass transition temperature (Tg) for concentrations of PEG less than 20%. This effect is not only enhanced by the LMW but also by increasing its content up to 20%. As expected, both T? and Tg decrease when increasing PEG molar mass and content up to 20%, which demonstrates the effectiveness of PEG to act as a plasticizer of PLA.

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