Controlling the crystal structure of precisely spaced polyethylene-like polyphosphoesters

Haider, Tobias; Suraeva, Oksana; O�Duill, Miriam L.; Mars, Julian; Mezger, Markus; Lieberwirth, Ingo; Wurm, Frederik R.

Abstract

Understanding polymer crystallization is important for polyethylene-like materials. A small fraction of monomers with functional groups within the polyethylene chain can act as crystallization “defects”. Such defects can be used to control the crystallization behavior in bulk and to generate functional anisotropic polymer crystals if crystallized from a dilute solution. Due to their geometry, phosphate groups cannot be incorporated in the polyethylene lamellae and thus control chain folding and crystal morphology. Herein, the synthesis and crystallization behavior for three different long-chain polyphosphates with a precise spacing of 20, 30, and 40 CH2-groups between each phosphate group are reported. Monomers were prepared by esterification of ethyl dichlorophosphate with respective tailor-made unsaturated alcohols. Acyclic diene metathesis (ADMET) polymerization and subsequent hydrogenation were used to receive polyethylene-like polyphosphoesters with molecular weights up 23 100 g mol−1. Polymer crystallization was studied from the melt and dilute solution. Samples were characterized by differential scanning calorimetry (DSC), small-angle X-ray scattering (SAXS), wide-angle X-ray scattering (WAXS), transmission electron microscopy (TEM), and atomic force microscopy (AFM). A change in crystal structure from pseudo-hexagonal to orthorhombic was observed from the “C20” to the “C40” polymer. Melting points and lamellar thicknesses increased with the length of the aliphatic spacer from 51 °C (“C20”) to 62 °C (“C30”) and 91 °C (“C40”). Values for the long periods in bulk (3.1 nm for C20, 4.8 nm for C30, and 7.2 nm for C40) obtained by SAXS and TEM are in qualitative agreement. The thickness of the crystalline part obtained by AFM and TEM increased from about 1.0 nm (C20) to 2.0 nm (C30) to 2.9 nm (C40). Our systematic library of long-chain polyphosphates will allow designing anisotropic polymer colloids by crystallization from solution as functional and versatile colloid platform.

Citation

Haider, T., Suraeva, O., O’Duill, M. L., Mars, J., Mezger, M., Lieberwirth, I., & Wurm, F. R. (2020). Controlling the crystal structure of precisely spaced polyethylene-like polyphosphoesters. Polymer Chemistry, 11(20), 3404-3415. https://doi.org/10.1039/d0py00272k

• Journal Article Type: Article
• Acceptance Date: May 3, 2020
• Online Publication Date: May 5, 2020
• Publication Date: May 28, 2020
• Deposit Date: Jun 29, 2020
• Publicly Available Date: Jul 2, 2020
• Journal: Polymer Chemistry
• Print ISSN: 1759-9954
• Electronic ISSN: 1759-9962
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 11
• Issue: 20
• Pages: 3404-3415
• DOI: https://doi.org/10.1039/d0py00272k
• Keywords: Organic Chemistry; Biochemistry; Bioengineering; Polymers and Plastics
• Public URL: https://nottingham-repository.worktribe.com/output/4711268
• Publisher URL: https://pubs.rsc.org/en/content/articlelanding/2020/py/d0py00272k#!divAbstract
• Additional Information: : This document is Similarity Check deposited; : Supplementary Information; : Miriam L. O'Duill (ORCID); : Julian Mars (ORCID); : Markus Mezger (ORCID); : Markus Mezger (ResearcherID); : Ingo Lieberwirth (ORCID); : Frederik R. Wurm (ORCID); : Frederik R. Wurm (ResearcherID); : Single-blind; : Received 18 February 2020; Accepted 3 May 2020; Accepted Manuscript published 5 May 2020; Advance Article published 14 May 2020; Version of Record published 26 May 2020