Comparative Morphological Study of Poly(dioxolane)/Poly(methyl methacrylate) Segmented Networks and Blends by ¹³C Solid-State NMR and Thermal Analysis

Abstract

Nanostructured amphiphilic segmented networks based on poly(1,3-dioxolane) (PDXL) and poly(methyl methacrylate) (PMMA) have been synthesized by radical copolymerization of α,ω-diacrylate PDXL with methyl methacrylate (MMA). The corresponding polymer blends have been prepared by the radical polymerization of MMA in the presence of α,ω-dihydroxy-PDXL. The multiphase behavior of the segmented networks and polymer blends have been compared by making use of solid-state 13C CP/MAS NMR spectroscopy, dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and thermogravimetrical analysis (TGA). For the network structures, the combined analysis of the proton spin−lattice relaxation times (T 1H) and proton spin-lock relaxation times (T 1 ρ H) revealed small PDXL domain sizes between 1 and 20 nm. DSC and DMA analysis also showed the forced compatibility of the network components. In the case of the polymer blends, the phase morphology strongly depends on the PDXL weight fraction. For blends with PDXL fractions higher than 20 wt %, T 1H relaxometry, DSC, and DMA analysis evidenced the presence of a heterogeneous phase morphology (domain sizes > 20 nm) that allows for the crystallization of the PDXL-rich domains.

Coordination Chemistry of [Co(acac)2] with N‐Doped Graphene: Implications for Oxygen Reduction Reaction Reactivity of Organometallic Co‐O4‐N Species

“…[17] On the other hand, an ew peak appeared about 0ppm in the spectrum of the Co II -15 N-A-rG-Os ample (Figure 2a). [17] On the other hand, an ew peak appeared about 0ppm in the spectrum of the Co II -15 N-A-rG-Os ample (Figure 2a).…”

Coordination Chemistry of [Co(acac)2] with N‐Doped Graphene: Implications for Oxygen Reduction Reaction Reactivity of Organometallic Co‐O4‐N Species

“…To understand the chemical environment of Co II -A-rG-O, we prepared aC o II - 15 13 CM AS SSNMR spectrum of 15 N-A-rG-O exhibited no peaks assignable to primary alkyl groups at 0ppm. [17] On the other hand, an ew peak appeared about 0ppm in the spectrum of the Co II -15 N-A-rG-Os ample (Figure 2a). It is reasonable to assume that this peak originates from the methyl groups in [Co II (acac) 2 ]…”

An Efficient Thermal Elimination Pathway toward Phosphodiester Hydrogels via a Precursor Approach

“…The use of a thermal elimination avoids the use of a base and the associated issues described above. The resulting hydrogel materials are analyzed with solid‐state carbon and phosphorus NMR spectroscopy 27–30…”