Fellows Alexander Paul, Puhan Debashis, Wong Janet S S, Casford Michael T L, Davies Paul B
Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
Department of Mechanical Engineering, Imperial College London, Exhibition Road, London SW7 2AZ, UK.
Polymers (Basel). 2022 Jan 4;14(1):192. doi: 10.3390/polym14010192.
The blend of polyetheretherketone (PEEK) and polybenzimidazole (PBI) produces a high-performance blend (PPB) that is a potential replacement material in several industries due to its high temperature stability and desirable tribological properties. Understanding the nanoscale structure and interface of the two domains of the blend is critical for elucidating the origin of these desirable properties. Whilst achieving the physical characterisation of the domain structures is relatively uncomplicated, the elucidation of structures at the interface presents a significant experimental challenge. In this work, we combine atomic force microscopy (AFM) with an IR laser (AFM-IR) and thermal cantilever probes (nanoTA) to gain insights into the chemical heterogeneity and extent of mixing within the blend structure for the first time. The AFM-IR and nanoTA measurements show that domains in the blend are compositionally different from those of the pure PEEK and PBI polymers, with significant variations observed in a transition region several microns wide in proximity to domain boundary. This strongly points to physical mixing of the two components on a molecular scale at the interface. The versatility intrinsic to the combined methodology employed in this work provides nano- and microscale chemical information that can be used to understand the link between properties of different length scales across a wide range of materials.
聚醚醚酮（PEEK）和聚苯并咪唑（PBI）的共混物产生了一种高性能共混物（PPB），由于其高温稳定性和理想的摩擦学性能，它在多个行业中是一种潜在的替代材料。了解共混物两个区域的纳米级结构和界面对于阐明这些理想性能的来源至关重要。虽然实现区域结构的物理表征相对简单，但阐明界面处的结构却面临重大的实验挑战。在这项工作中，我们首次将原子力显微镜（AFM）与红外激光（AFM-IR）和热悬臂探针（nanoTA）相结合，以深入了解共混物结构内的化学不均匀性和混合程度。AFM-IR和nanoTA测量结果表明，共混物中的区域在组成上与纯PEEK和PBI聚合物的区域不同，在靠近区域边界的几微米宽的过渡区域观察到显著变化。这有力地表明了两种组分在界面处分子尺度上的物理混合。这项工作中采用的组合方法固有的多功能性提供了纳米和微米尺度的化学信息，可用于理解广泛材料中不同长度尺度性能之间的联系。
