Hohl Diana Kay, Ferahian Anne-Cécile, Montero de Espinosa Lucas, Weder Christoph
Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland.
ACS Macro Lett. 2019 Nov 19;8(11):1484-1490. doi: 10.1021/acsmacrolett.9b00710. Epub 2019 Oct 24.
A modular approach for the design of two-component supramolecular polymer (SMP) networks is reported. A series of materials was prepared by blending two (macro)monomers based on trifunctional poly(propylene oxide) (PPO) cores that were end-functionalized with hydrogen-bonding 2-ureido-4[1]pyrimidinone (UPy) groups. One monomer was based on a PPO core with a number-average molecular weight () of 440 g mol. The SMP formed by this building block is a glassy, brittle material with a glass transition temperature () of about 86 °C. The second monomer featured a PPO core with an of 3000 g mol. The SMP formed by this building block adopts a microphase-segregated morphology that features a rubbery phase with a of -58 °C and crystalline domains formed by the UPy assemblies, which act as physical cross-links and melt around 90-130 °C. Combining the two components allows access to microphase-segregated blends comprised of a rubbery phase constituted by the high- cores, a glassy phase formed by the low- component, and a crystalline phase formed by UPy groups. This allowed tailoring of the mechanical properties and afforded materials with storage moduli of 37-609 MPa, tensile strengths of 2.0-5.4 MPa, and melt viscosities of as low as 11 Pa s at 140 °C. The materials can be used as reversible adhesives.
报道了一种用于设计双组分超分子聚合物（SMP）网络的模块化方法。通过将两种基于三官能聚环氧丙烷（PPO）核的（宏观）单体共混制备了一系列材料，这些核用氢键连接的2-脲基-4[1]嘧啶酮（UPy）基团进行了末端官能化。一种单体基于数均分子量（）为440 g/mol的PPO核。由该结构单元形成的SMP是一种玻璃态脆性材料，玻璃化转变温度（）约为86°C。第二种单体的PPO核的为3000 g/mol。由该结构单元形成的SMP呈现微相分离形态，其特征是具有-58°C的橡胶相和由UPy组装体形成的结晶域，这些组装体充当物理交联点并在90-130°C左右熔化。将这两种组分结合起来，可以得到由高核构成的橡胶相、低组分形成的玻璃相和UPy基团形成的结晶相组成的微相分离共混物。这使得能够调整机械性能，并提供储能模量为37-609 MPa、拉伸强度为2.0-5.4 MPa且在140°C时熔体粘度低至11 Pa·s的材料。这些材料可用作可逆粘合剂。
