Final answer:
The Flory-Huggins parameter (Χ) measures polymer-solvent interactions and is also used to predict the miscibility of two polymers, following the principle 'like dissolves like'.
Step-by-step explanation:
The Flory-Huggins parameter, often represented by Χ (chi), is a dimensionless quantity that quantifies the interaction between polymer and solvent molecules. When applied to polymer-polymer interactions, it explains the miscibility of two polymers. If Χ is negative or very small and positive, this indicates good miscibility, meaning that the intermolecular interactions, such as dipole-dipole attractions or hydrogen bonding, are favorable or comparable to those within pure components.
Conversely, a large positive Χ value suggests poor miscibility, as it implies that the interactions between the different polymers are weaker than those within each polymer species. The concept aligns with the principle "like dissolves like", indicating that polymers with similar polarity are more likely to be miscible.