Surface Lubricity and Optical Stability in PS via Trace PDMS

Assumption under test

Low-level internal lubricants cannot produce durable, low-friction polystyrene surfaces without blooming, haze, or surface oiling.

Why this assumption matters

Polystyrene is widely used in consumer-facing products where friction, dust adhesion, fingerprinting, and surface wear are persistent issues. The dominant mitigation strategy relies on coatings or surface treatments, increasing cost and failure risk.

Edge of Practice experiment

Compound general-purpose polystyrene with 0.5–2 wt% low–molecular weight polydimethylsiloxane (PDMS). Injection mold flat plaques under standard processing conditions without surface treatment or post-processing.

During molding, PDMS migrates toward the polymer–air interface, forming a nanometer-scale lubricious layer driven purely by surface energy minimization. No chemical bonding or phase reaction occurs.

Primary measurements

• Tribological testing (pin-on-disk or sliding friction) versus neat PS
• Optical haze and gloss before and after standardized abrasion
• Visual inspection for blooming or oiling after mild heating (40 °C)

Failure condition

Any visible surface blooming, oiling, haze increase, or loss of optical clarity after 24 hours at 40 °C or after solvent wipe constitutes failure.

Pass condition

A reduction in friction coefficient of ≥30% compared to neat PS, with no visible surface oiling and no measurable haze increase.

What breaks if this assumption is false

If the assumption fails, commodity PS can achieve durable, low-friction, dust-resistant surfaces without coatings, chemistry, or additional process steps—reframing internal additives as surface physics tools rather than bulk modifiers.

Status: Final · Immutable