Interaction of plasticizers with blend components

This behavior can be expected from systems in which entropic factors can be neglected. ABS/PMMA blend plasticized with a mixtme of ethylene and propylene carbonates is an example of system where entropic factors play a role. PMMA is plasticized in polymer electrolytes to increase ionic conductivity. Addition of a plasticizer in an amount sufficient to achieve required conductivity decreases the mechanical performance of the gel to the level that it needs to be reinforced. ABS is added as reinforcing polymer and sufficient mechanical properties are obtained. Two phases are obtained plasticizer-reach phase giving pathway for ion transportation and ABS-rich phase which acts as a matrix increasing mechanical performance. ABS is miscible with PMMA forming transparent blends if no plasticizer is added. Addition of the plasticizer results in phase separation (opaque materials) because of incompatibility between ABS and the plasticizer. This is an example of a system in which the plasticizer is not uniformly distributed among participating polymers but the plasticizer is found in the PMMA-rich phase.  

The following equation was proposed to calculate the glass transition temperature of polymer blend and to account for solvent quality of the plasticizer by the use of parameter b  

2 indices of plasticizer and polymer, respectively b parameter characteristic of solvent quality of plasticizer. 

Molecular weight of a polymer and a certain concentration of the plasticizer determine the uniformity blend. If the molecular weight of PVC used in CPE-PVC-DOP blend is doubled, the concentration of DOP needed to obtain a homogeneous mixture is increased from 55 wt% to 70 wt% of DOP. A statistical thermodynamic approach was developed for mixing of polymers, small molecules (plasticizers), and holes which are different in sizes. Plasticizer efficiency is determined by polymer-plasticizer interaction and plasticizer segment size. 

Interaction of a plasticizer and matrix polymer was described in Section 5.2 as being caused by  

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