6533b853fe1ef96bd12ad554
RESEARCH PRODUCT
Cooperativity Scaling and Free Volume in Plasticized Polylactide
Adam IngramLaurent DelbreilhAlain GuinaultRoman GolovchakSteven AraujoEric DargentSandra DomenekCyrille FauchardRoman SzatanikNicolas Delpouvesubject
Materials scienceMatériaux [Sciences de l'ingénieur]Polymers and Plasticsgenetic structuresThermodynamicsCooperativity02 engineering and technologyActivation energyDielectric010402 general chemistry01 natural sciences[SPI.MAT]Engineering Sciences [physics]/MaterialsInorganic ChemistryFragilityBiopolymersmiscible polymer blendsMaterials ChemistryActivation energycharacteristic length[PHYS]Physics [physics]Drop (liquid)Organic polymersOrganic Chemistry021001 nanoscience & nanotechnology0104 chemical sciencesAmorphous solidfragilty[CHIM.POLY]Chemical Sciences/PolymersVolume (thermodynamics)positron-annihilationtemperature-dependence[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci]0210 nano-technologyGlass transitionPlastics[PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft]dynamic heterogeneitydescription
The authors would like to thank the region Haute Normandie for their financial support and the acquisition of the Broadband Dielectric Spectrometer. R.G. acknowledges U.S. National Science Foundation (Grant no. DMR-1725188) for the acquisition of PAL spectrometer. The experimental evidence of the increase of activation energy associated with the super Arrhenius behavior governing amorphous polylactide by free volume variations has been obtained through a combination of calorimetric, dielectric, and positron annihilation lifetime measurements. The amount of free volume in polylactide was controlled by the amount of acetyltributylcitrate plasticizer in the composition. Plasticization is shown to decrease both the fragility index and the scale of cooperative motions at the glass transition. The calculations of volume and energetic components of kinetic fragility reveal that the fragility drop is governed by the change in the size of cooperative rearranging region. As a result, direct correlation has been established between cooperativity and activation energy for the entire plasticized polylactide series. It is also shown that cooperativity variations with both temperature and plasticizer content can be simplified as a master curve with free volume.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2019-08-15 |