Influence of Cross-Linker Concentration on the Mechanical Properties and Glass Transition Temperature of an Adhesive

The quantity of cross-linker plays a significant role in determining the properties of the adhesive, a factor of paramount importance for practical applications. To elucidate this relationship, the obtained films were subjected to tensile tests, and the resulting curves are illustrated in Figure 2b. This analysis revealed that the mechanical properties of the adhesive could be effectively regulated by adjusting the quantity of BMI utilized. Notably, ESOF-I1.0 exhibited a higher stress at break (18.45 MPa) compared to ESOF-I0.6 (10.19 MPa), directly attributable to the increased utilization of BMI during the preparation process. Moreover, the toughness of ESOF-I1.0, as determined by the integral area of the curves, was approximately 2.4 MJ m-3, whereas ESOF-I0.6 exhibited a lower toughness of 1.9 MJ m-3. These tensile results unequivocally demonstrate that the mechanical properties of the adhesive can be customized to meet specific requirements. Furthermore, the glass transition temperature (Tg) gradually increased with the quantity of BMI, as observed from the DSC results (Figure 4d). For example, ESOF-I0.6 transitioned from a glass state to a rubber state at around 16.8℃, whereas the Tg of ESOF-I1.0 was approximately 31.2℃. This observed increase in Tg can be attributed to the strengthened interaction between molecular chains with the increased amount of BMI.