Miscibility and Phase Separation in PMMA/SAN Blends Investigated by Nanoscale AFM-IR

Area of Science:

• Polymer Science
• Materials Science
• Nanotechnology

Background:

• Previous methods for characterizing poly(methyl methacrylate) (PMMA) and styrene-acrylonitrile (SAN) blend miscibility and phase separation have limitations, leading to inconsistent results.
• The influence of composition and processing temperature on PMMA/SAN miscibility remains incompletely understood due to these characterization challenges.

Purpose of the Study:

• To investigate the phase separation of PMMA/SAN blends using a novel nanoscale AFM-IR technique.
• To chemically identify and classify phase morphology within the nanometer regime.
• To elucidate the dependence of blend miscibility on composition and thermal treatments.

Main Methods:

• Utilized nanoscale Atomic Force Microscopy with Infrared Spectroscopy (AFM-IR) for high-resolution chemical identification of blend morphology.
• Analyzed changes in PMMA/SAN blend morphology under various thermal treatments.
• Investigated miscibility and phase separation at the nanoscale.

Main Results:

• Successfully visualized and defined phase separation in PMMA/SAN blends.
• Demonstrated the dependence of miscibility on the mixing ratio of the polymers.
• Observed morphological changes and the formation of distinct phases with sharp boundaries upon increasing temperature, with onset around 100 °C.

Conclusions:

• Nanoscale AFM-IR provides precise chemical identification and classification of phase morphology in polymer blends.
• The study clarifies the composition and temperature-dependent nature of PMMA/SAN blend miscibility.
• Thermal treatment significantly impacts PMMA/SAN blend morphology, initiating phase separation at approximately 100 °C.