The Sequence of Molecular Weight, Crystallinty and CompressiveMechanical Properties: A Case Study of Binary Polyethylene Glycol Blends

The structure of polymers affects their physicochemical properties, including the aqueous solubilityof water-soluble polymers, e.g., polyethylene glycol (PEG). A mixture of PEGs is customarily usedfor pharmaceutical applications to yield compositions with improved dissolution profiles ormechanical properties, depending on the blend ratio, molecular weight (MW), molecular weightdistribution (MWD) of the mixture, and its crystallinity. Correlating the compressive mechanicalproperties of the blends with their MW and MWD, which are influenced by changes in thecrystallinity as an intermediary physical characteristic, remained unanswered.To this end, the trends of the changes observed in the compressive mechanical properties andcrystallinity were traced for six single PEGs as a function of their MW and MWD after clearing theirthermal history. Then, five binary mixtures were investigated to extend the findings. It was observedthat the mixtures with the same MW showed the same mechanical properties. It was concluded thatthe mechanical properties of the mixtures can be predicted by estimating the crystallinity, MW, andMWD of the binary PEG mixtures

کلیدواژه ها:

Polymer blends ، PEG ، Crystallization ، Molecular weight.