Unveiling coumarone resin as a tackifier in SBS-based PSA systems-a comprehensive viscoelasticity study

Area of Science:

• Polymer Science
• Materials Science
• Adhesives Technology

Background:

• Styrene-butadiene-styrene (SBS) block copolymers are widely used in Pressure Sensitive Adhesives (PSA) due to their tack and processability.
• A significant challenge in PSA formulation is balancing adhesion (tack) and cohesion (shear strength).

Purpose of the Study:

• To investigate coumarone resin as a dual-phase tackifier for SBS-based PSA formulations.
• To evaluate the impact of coumarone resin on the viscoelastic properties and performance of SBS PSAs.

Main Methods:

• Formulation of SBS-based PSAs with varying concentrations of coumarone resin.
• Rheological analysis to determine viscoelastic properties (G', G″) and compatibility.
• Performance testing including peel strength and Shear Adhesion Failure Temperature (SAFT).

Main Results:

• Confirmed strong compatibility between coumarone resin and SBS, leading to improved thermal stability.
• Rheological studies revealed a broader viscoelastic plateau and balanced elasticity-viscosity relationship in coumarone-modified SBS.
• Optimal formulations met the Dahlquist criterion, achieving high peel strength (~27 N/25 mm) and SAFT (~70 °C).

Conclusions:

• Coumarone resin acts as an effective dual-phase tackifier for SBS-based PSAs.
• The addition of coumarone resin significantly enhances PSA performance, particularly peel strength and thermal stability.
• This study demonstrates the potential for developing tailored, cost-effective removable PSAs using coumarone-modified SBS.