Diffusion coefficients of water and leachables in methacrylate-based crosslinked polymers using absorption...

Area of Science:

• Polymer Science
• Biomaterials Science
• Dental Materials

Background:

• Water diffusion and monomer leaching in dental adhesives cause mechanical softening and degradation.
• Accurate diffusion coefficient data are essential for designing durable polymeric dental adhesives.

Purpose of the Study:

• To determine the diffusion coefficients of water and leachables in sixteen methacrylate-based crosslinked polymers.
• To investigate the correlation between diffusion coefficients, crosslink density, and hydrophilicity.

Main Methods:

• Absorption experiments were conducted to measure mass changes in polymer samples.
• Numerical solutions of two-dimensional diffusion equations were used to interpret experimental data.
• Diffusion coefficients were calculated for various methacrylate-based polymers.

Main Results:

• Diffusion coefficients ranged from 1.05 × 10(-8) cm(2)/sec (TMTMA) to 3.15 × 10(-8) cm(2)/sec (T4EGDMA).
• An inverse correlation (R(2) = 0.41) was observed between diffusion coefficients and crosslink density/hydrophilicity.
• Stronger correlations (R(2) = 0.95) were found for polymers with similar repeat units, indicating specific interaction mechanisms.

Conclusions:

• Diffusion coefficients are critical parameters for the mechanical design of dental adhesives.
• Crosslink density and hydrophilicity significantly influence water diffusion and leaching.
• The study elucidates the mechanisms of water-polymer interaction, informing future material development.