The present work describes the role of accurate selection of diisocyanate on the adhesion strength of polyurethanes (PUs). The concentration of diisocyanate induces the hard segment (HS) in the main architecture of PUs which decides the viscoelastic properties of the polymers. A balanced ratio of viscoelastic properties ultimately determines the adhesion strength. The composition of the polymers consists of a blend of macrodiol of hydroxyl‐terminated polybutadiene and polypropylene glycol with different molecular weights. Isophorone diisocyanate (IPDI) is used to develop the urethane linkages by maintaining its contribution from 28 to 67% as HS contents. It determines the adhesion strength of the final product. The adhesion strength is evaluated by texture analyzer and 180° peel test. The probe tack analysis shows maximum adhesion energy of 156.2 J cm⁻² and 180° peel test shows 18.80 N/25 mm peel force. The glass‐transition (T _g) values obtained through differential scanning calorimetry are in good agreement with theoretically calculated Flory–Fox temperature. The proportion of the loss tangent to the storage modulus (tan δ/E′) shows the optimum value of 2.80 MPa⁻¹. The ideal concentration of IPDI results to achieve better adhesion properties of PU pressure sensitive adhesives. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47124.

中文翻译：

---

异佛尔酮二异氰酸酯在优化聚氨酯压敏胶粘剂粘合趋势中的作用

本工作描述了正确选择二异氰酸酯对聚氨酯（PU）粘合强度的作用。二异氰酸酯的浓度会在PU的主要结构中诱发硬链段（HS），这决定了聚合物的粘弹性。平衡比例的粘弹性质最终决定了粘合强度。聚合物的组成由具有不同分子量的羟基封端的聚丁二烯大分子二醇和聚丙二醇组成。异佛尔酮二异氰酸酯（IPDI）通过保持其作为HS含量的28％至67％来发展氨基甲酸酯键。它决定了最终产品的粘合强度。通过质地分析仪和180°剥离测试评价粘合强度。探针粘性分析显示最大附着力为156。^-2和180°剥离测试显示18.80 N / 25 mm剥离力。通过差示扫描量热法获得的玻璃化转变温度（T _g）与理论计算的Flory-Fox温度高度吻合。损耗角正切与储能模量的比例（tanδ/ E'）显示最佳值为2.80 MPa ^-1。理想浓度的IPDI可以实现PU压敏胶的更好粘合性能。©2018 Wiley Periodicals，Inc.J.应用 Polym。科学 2019，136，47124。