Enhanced Heat Resistance of Acrylic Pressure-Sensitive Adhesive by Incorporating Silicone Blocks Using Silicone-Based Macro-Azo-Initiator

Abstract

To improve the heat resistance of acrylic-based pressure-sensitive adhesive (PSA), silicone-block-containing acrylic PSAs (SPSAs) were synthesized using a polydimethylsiloxane (PDMS)-based macro-azo-initiator (MAI). To evaluate the heat resistance of the PSA films, the probe tack and 90° peel strength were measured at different temperatures. The acrylic PSA showed that its tack curves changed from balanced debonding at 25 °C to cohesive debonding at 50 °C and exhibited a sharp decrease. However, in the case of SPSA containing 20 wt% MAI (MAI20), the balanced debonding was maintained at 75 °C, and its tack value hardly changed with temperature. As the MAI content increased, the peel strength at 25 °C decreased due to the microphase separation between PDMS- and acryl-blocks in SPSA, but the shear adhesion failure temperature (SAFT) increased almost linearly from 41.3 to 122.8 °C. Unlike stainless steel substrate, SPSA showed improved peel strength on a polypropylene substrate due to its low surface energy caused by PDMS block. Owing to the addition of 20 wt% silicone-urethane dimethacrylate oligomer and 200 mJ/cm2 UV irradiation dose, MAI20 showed significantly increased 90° peel strength at 25 °C (548.3 vs. 322.4 gf/25 mm for pristine MAI20). Its heat resistance under shear stress assessed by shear adhesion failure test (SAFT) exhibited raising in failure temperature to 177.3 °C when compared to non-irradiated sample.

Influence of storage time on the useful properties of silicone pressure-sensitive adhesives

“…In most cases, the values of the properties tested did not differ significantly between the tape stored for 7 years and the samples continuously tested immediately after producing. This confirms the information about the unique properties of Si-PSA described in the literature [5,[8][9][10][16][17][18][19].…”

“…The starting temperature for the test was room temperature: 22°C. The temperature was changing at a rate of 1°C per minute [17][18].…”

Fabrication of Flexible Electrode with Sub-Tenth Micron Thickness Using Heat-Induced Peelable Pressure-Sensitive Adhesive Containing Amide Groups

“…Because of the balanced cohesion force and free volume [ 19 ], PSAs are peeled from adherends with high peel strength via adhesive failure; thus, no debris of the PSA is left on the adherends [ 20 ]. However, the lack of strong intermolecular interactions generally causes cohesion failure when PSAs are peeled at high temperature [ 21 ].…”

Synthesis of Polyetheramine-Grafted Epoxidized Natural Rubber and Its Role in Humidity Adhesive Sensors

“…For instance, a dopamine moiety is introduced to various polymer backbones to introduce enhanced wet adhesion . Similarly, the thermal resistance of acrylic adhesives has been reported to improve after incorporating silicone blocks in the polymer chain . The other strategy commonly leveraged is incorporating functional molecules in the adhesive base formulation to achieve desired functional attributes.…”

“…8 Similarly, the thermal resistance of acrylic adhesives has been reported to improve after incorporating silicone blocks in the polymer chain. 9 The other strategy commonly leveraged is incorporating functional molecules in the adhesive base formulation to achieve desired functional attributes. For instance, silicone acrylate, a functional material synthesized from the silicone backbone, is commonly blended with a variety of acrylic adhesive formulations to improve adhesion strength.…”