Koch Karin, Geller Sven, Acar Kubilay, Bach Patricia, Tsarenko Ekaterina, Schmidt Annette
Institut für Physikalische Chemie, Department Chemie, Universität zu Köln, 50923 Köln, Germany.
Polymers (Basel). 2020 Apr 2;12(4):787. doi: 10.3390/polym12040787.
The incorporation of nanoparticles into soft matrices opens a broad spectrum of novel property combinations. However, one of the major challenges for these systems remains the compatibilization of particles with the surrounding matrix by proper surface functionalization. For silicon-based systems or liquid crystalline phases, polydimethylsiloxane (PDMS) brushes at the surface of particles increase the stability against particle agglomeration in such systems. Here, we report a novel approach for the functionalization of particles with a polysiloxane brush by surface-initiated ring-opening polymerization of a cyclosiloxane. For this purpose, surface hydroxy groups of silica and silica-coated hematite particles are used as initiators in combination with phosphazene bases as catalysts. The ring-chain equilibrium of a model-based solution polymerization is investigated in detail to find the appropriate reaction parameters. The corresponding molar masses are determined and compared by H-NMR and SEC measurements to confirm the underlying mechanism. In the resulting hybrid nanostructures, a covalently bound PDMS fraction is achieved up to 47 mass %.
将纳米颗粒掺入软质基质中可产生一系列广泛的新型性能组合。然而，这些体系面临的主要挑战之一仍是通过适当的表面功能化使颗粒与周围基质相容。对于硅基体系或液晶相而言，颗粒表面的聚二甲基硅氧烷（PDMS）刷可提高此类体系中颗粒抗团聚的稳定性。在此，我们报道了一种通过环硅氧烷的表面引发开环聚合制备带有聚硅氧烷刷的颗粒功能化新方法。为此，将二氧化硅和二氧化硅包覆的赤铁矿颗粒的表面羟基用作引发剂，并结合磷腈碱作为催化剂。详细研究了基于模型的溶液聚合的环链平衡，以找到合适的反应参数。通过H-NMR和SEC测量确定并比较相应的摩尔质量，以确认潜在机制。在所得的杂化纳米结构中，共价结合的PDMS部分可达47质量%。
