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.
Highlights
Pressure-sensitive adhesive (PSA) is a semisolid material that adheres to various substrates at room temperature without additional chemical reactions and does not leave a residue after removal.Owing to these unique characteristics, it has been used in various industrial fields, such as packaging, labeling, medical, pharmaceutical, automotive, and electronics [1,2,3,4]
As the MAI content increased, the molecular weight of Silicone Block-Containing Acrylic PSA (SPSA) decreased, and its PDI value increased. This is well understood by considering that the molecular weight of acrylic pressure-sensitive adhesive (PSA) decreases and its PDI
As a result of gel formation, the SPSA becomes non-homogenous and its molecular mass is most likely determined only for the smaller molecules of polymer dissolved in solvent, not for the polymer in gel-like state dispersed in solvent
Summary
Pressure-sensitive adhesive (PSA) is a semisolid material that adheres to various substrates at room temperature without additional chemical reactions and does not leave a residue after removal. Joo et al prepared a semi-interpenetrating polymer network (semi-IPN) structure in PSA tape using trifunctional acrylic monomers of different lengths, followed by UV irradiation They reported greatly improved heat resistance [11]. It is difficult to obtain good adhesion characteristics with this method To overcome this problem, a number of methods have been developed: a silicone adhesive is blended with an aqueous acrylic adhesive using an emulsifier [12], a reactive silicone resin-type seed is used for emulsion polymerization with an acrylic monomer [13], or a prepolymer, which is prepared with functionalized polydimethylsiloxane (PDMS), is introduced into the acrylic chain via copolymerization [14]. The adhesion properties and thermal stability of SiUDMA-modified SPSA were evaluated according to the two above-mentioned factors
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
