Incorporation of methacryloisobutyl POSS in bio‐based copolymers by nitroxide mediated polymerization in organic solution and miniemulsion

Abstract

In this study, nitroxide mediated polymerization of methacryloisobutyl POSS (POSSMA) and bio-sourced monomers: isobornyl methacrylate (IBOMA) and C13 methacrylate (C13MA, an alkyl methacrylate with an average chain length of 13 units) was conducted in solution (toluene) and miniemulsion. BlocBuilder-MA (with 10 mol% acrylonitrile [AN] controlling co-monomer, for the solventbased system) and Dispolreg 007 (for the miniemulsion) were used as the alkoxyamine for initiation and controlling the polymerization. POSSMA/ IBOMA/C13MA effective terpolymerization (having 10 mol% AN controlling comonomer) with monomer conversion (X) <72% in toluene resulted in resins with M n up to 21.3 kg mol −1 and Ð < 1.67. Next, terpolymerizations were conducted in dispersed aqueous media to completely remove the organic solvent, resulting in polymers with M n up to 46.7 kg mol −1 and Ð < 1.65. The successful chain extension of poly(IBOMA/AN) with a mixture of POSSMA/C13MA/AN (M n = 74.1 kg mol −1 and Ð = 1.55) showed high chain-end fidelity, exemplified by a clear, monomodal shift in the GPC chromatogram from the macroinitiator. Finally, it was shown that the addition of 20 mol% POSSMA improved the decomposition temperature of bio-based polymers of IBOMA/C13MA by 15%.

Recyclable Polymers with Boronic Ester Dynamic Bonds Prepared by Miniemulsion Polymerization

“…The decomposition of unreacted monomers occurs at temperatures below 200 °C, causing an increase in decomposition rate (i.e., formation of a peak in derivative weights (%/°C) vs temperature graphs, Figure ). The first decomposition temperature ( T dec,1 , 10% weight loss) might correspond to the breakage of dynamic covalent bonds within the BG dimers, and the last stage suggests the cleavage of the O-isobornyl bond in IBOMA and the formation and elimination of camphene at higher temperatures. , According to the results, T dec,1 ’s for dimer 5%, 10%, and 15% are slightly lower than the T dec,1 ’s for IBOMA/C13MA copolymers with the same monomer ratios prepared in miniemulsion . This decrease in T dec,1 ’s is even higher if it is compared to our previous results on boronic ester cross-linked polymer blends with similar monomer compositions (Δ T dec,1 up to 104 °C) .…”

“…Isobornyl methacrylate (IBOMA, 71% biocarbon content) derived from pine sap (camphene) has a high glass transition temperature ( T g ) ( T g,P(IBOMA) = 110–200 °C) , and used to improve the T g of polymers . Alkyl methacrylates with an average side chain aliphatic size of 13.0 (termed here as C13MA, 76% biocarbon content, derived from natural oils) were incorporated into resins to decrease the T g ( T g,P(C13MA) = −46 °C) and improve the flexibility of polymer chains. , Using IBOMA and C13MA, polymers with tunable T g can be produced to meet the criteria for a specific application. − Nitroxide-mediated polymerization (NMP), as one of the simplest reversible deactivation radical polymerization (RDRP) techniques, was utilized to improve control over the polymerization (linear increase in average molecular weight ( M n ) vs monomer conversion ( X )), to reduce discoloration, to obtain tighter molecular weight distribution ( Đ ) leading to lower viscosities for application in coatings, and to enhance chain-to-chain compositional homogeneity and the formation of well-defined microstructures. − For the nitroxide, we used 3-(((2-cyanopropan-2-yl)­oxy)-(cyclohexyl)­amino)-2,2-dimethyl-3-phenylpropanenitrile (Dispolreg 007) alkoxyamine to initiate the miniemulsion polymerization of methacrylates, without any controlling comonomer as was typically required for NMP, at temperatures below 100 °C. , For miniemulsion, all that was needed beside the monomers and nitroxide was surfactant and long-chain alkyl-containing costabilizers. − …”

Reversible Deactivation Radical Polymerization Mediated by Nitroxides and Green Chemistry

“…However, in both cases, MW was several times higher than the theoretical value and Đ was 1.39–1.66 for polymerization in solution and 1.50–1.73 for polymerization in miniemulsion. The ternary copolymerization of the said monomers with methacryloyl silsesquioxane proceeded in a similar manner [ 124 ]. The sequential polymerization of monomers makes it possible to synthesize their block and gradient copolymers.…”

Synthesis of bio‐based poly(methacrylates) using SG1‐containing amphiphilic macroinitiators by nitroxide mediated miniemulsion polymerization

“…21,28 Isobornyl methacrylate (IBOMA, 71% bio carbon content, derived from pine sap) and C13-alkyl methacrylates (C13MA, 76% bio carbon content, from natural oils) can be used to synthesize copolymers with high bio-content with readily adjustable glass transition temperatures (T g s), as IBOMA provides stiffness while C13MA provides low temperature flexibility. [29][30][31][32] The IBOMA/C13MA copolymers can be used for coating and adhesive applications. We previously synthesized IBOMA/C13MA polymers by NMP using different initiation methods (pure BB and Dispolreg 007 alkoxyamine) in organic solvents and miniemulsions.…”