Graphene oxide reduces the hydrolytic degradation in polyamide-11. (22nd September 2017)

• Record Type: Journal Article
• Authors: Hocker, Samuel J.A.; Hudson-Smith, Natalie V.; Smith, Patrick T.; Komatsu, Christopher H.; Dickinson, Laura R.; Schniepp, Hannes C.; Kranbuehl, David E.
• Is Part Of: Polymer. Volume 126(2017)
• Page Start: 248
• Page End: 258
• Publication Date: 2017-09-22
• Subjects: Polyamide-11 -- Graphene oxide -- Hydrolysis; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2017.08.034
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: Graphene oxide (GO) was incorporated into polyamide-11 (PA11) via in-situ polymerization. The GO-PA11 nano-composite had elevated resistance to hydrolytic degradation. At a loading of 1 mg/g, GO to PA11, the accelerated aging equilibrium molecular weight of GO-PA11 was higher (33 and 34 kg/mol at 100 and 120 °C, respectively) compared to neat PA11 (23 and 24 kg/mol at 100 and 120 °C, respectively). Neat PA11 had hydrolysis rate constants (kH ) of 2.8 and 12 ( × 10 −2 day −1 ) when aged at 100 and 120 °C, respectively, and re-polymerization rate constants (kP ) of 5.0 and 23 ( × 10 −5 day −1 ), respectively. The higher equilibrium molecular weight for GO-PA11 loaded at 1 mg/g was the result of a decreased kH, 1.8 and 4.5 ( × 10 −2 day −1 ), and an increased kP, 10 and 17 ( × 10 −5 day −1 ) compared with neat PA11 at 100 and 120 °C, respectively. The decreased rate of degradation and resulting 40% increased equilibrium molecular weight of GO-PA11 was attributed to the highly asymmetric planar GO nano-sheets that inhibited the molecular mobility of water and the polymer chain. The crystallinity of the polymer matrix was similarly affected by a reduction in chain mobility during annealing due to the GO nanoparticles' chemistry and highly asymmetric nano-planar sheet structure. Graphical abstract: Highlights: Graphene oxide reduces extent of hydrolytic degradation in polyamide-11. Graphene oxide reduces molecular mobility in polyamide-11. Polyamide's amide hydrogen bonds with the graphene oxide surface.