Synthesis and Characterization of thermally stable Acrylic PSA using Silicone Urethane Methacrylate of Semi-IPN Structure

Abstract

To improve the thermal stability, polydimethylsiloxane (PDMS) is used and UV curing method employed. Silicone Urethane Methacrylate (SiUMA) was synthesized and introduced into acrylic Pressure Sensitve Adhesives (Acrylic PSA) as Semi- Interpenetrating Polymer Networks (IPN) structure. Through FT-IR the structure was defined. The kinetics and behavior of SiUMA (S1) were found by adding the photoinitiator (PI) 0.5, 1.0, 5.0 and 10phr, which were examined using photo-DSC (photo-DSC). After determining the PI amount 5.0phr, 1000mJ/㎠ UV intensity, added the SiUMA 20, 40, 60 and 80% to acrylic PSA which was prepared by radical polymerization and analyzed kinetic and behavior by photo-DSC, Real Time Infrared Spectroscopy (RTIR). Finally checking the peel strength shows the adhesion property. As increasing the amount of S1 and increasing the amount of PI, the reaction was greater. As increasing with the cross-linking, peel strength was dropped sharply which shows that surface change occurred. When it is applied to acrylic PSA by formed IPN structure, it will be influenced to increase the peel strength before UV curing but peel strength decrease sharply after UV curing because of S1s mobility to the interface-air. Next, Silicone urethane methacrylate (SiUMA) is applied to acrylic PSA using IPN structure with different chain length. Acrylic PSA was prepared by free radical polymerization and SiUMA was synthesized by additional polymerization by urethane linkage. Through urethane reaction, SiUMAs were prepared different length. Preparing of Synthetic Silicone Urethane Methacrylate formed Semi-IPN structure in the acrylic PSA, it can be verify thermal stability with the SAFT (Shear Adhesion Failure Temperature) using 1kg weights of plumb. Normally acrylic PSA easily be cleared from substrate prior to 50℃, but in case of containing S1 10%, it can resistant over 100℃. Photo-DSC shows that the 5phr photoinitiator (PI) and 1000mJ/㎠ of UV intensity were available to complete curing reaction. Short and long chain 2type chain polymer structures were confirmed through FT-IR, GPC. And through measuring the TGA, it can be checked cross-linking effect and improvement of the thermal resistance using the silicone materials. By ARES, analyzed the thermal property changes and visco-elastic changes were detected. In this study, mobility of silicone is detected moving onto the interface-air. The result of the study provide an information to improve the thermally stability using SiUMA by Semi-IPN structure in acrylic PSA.