skip to main content

Title: Synthesis of n ‐alkyl methacrylate polymers with pendant carbazole moieties and their derivatives

New methacrylate monomers with carbazole moieties as pendant groups were synthesized by multistep syntheses starting from carbazoles with biphenyl substituents in the aromatic ring. The corresponding polymers were prepared using a free‐radical polymerization. The novel polymers containN‐alkylated carbazoles mono‐ or bi‐substituted with biphenyl groups in the aromatic ring.N‐alkyl chains in polymers vary by length and structure. All new polymers were synthesized to evaluate the structural changes in terms of their effect on the energy profile, thermal, dielectric, and photophysical properties when compared to the parent polymer poly(2‐(9H‐carbazol‐9‐yl)ethyl methacrylate). According to the obtained results, these compounds may be well suited for memory resistor devices. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2019, 57, 70–76

more » « less
Award ID(s):
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Journal of Polymer Science Part A: Polymer Chemistry
Page Range / eLocation ID:
p. 70-76
Medium: X
Sponsoring Org:
National Science Foundation
More Like this

    Dual‐functional monomers consist of two distinctly different functional groups that enable chemical versatility. The most readily available epoxy‐methacrylate dual‐functional monomer is glycidyl methacrylate (GMA). In an effort to produce bio‐based, aromatic complements to GMA, asymmetric phenolic diols (vanillyl alcohol, syringyl alcohol, gastrodigenin, and tyrosol) were identified and selectively epoxidized at the aromatic hydroxyl followed by subsequent esterification at the aliphatic hydroxyl to prepare dual functional monomers, vanillyl alcohol epoxy‐methacrylate (VAEM), syringyl alcohol epoxy‐methacrylate (SAEM), gastrodigenin epoxy‐methacrylate (GDEM), and tyrosol epoxy‐methacrylate (TEM). These monomers are viable platforms for a multitude of applications due to their unique chemical functionalities. VAEM, SAEM, GDEM, and TEM were homopolymerized individually to produce aromatic, bio‐based epoxy‐functional thermoplastics analogous to poly(GMA). The molecular weight distributions and thermal properties of each polymer were evaluated, as were the surface characteristics of flow‐coated thin films from these polymers. Most of the newly prepared epoxy‐functional thermoplastics exhibited increased thermal stability (initial decomposition temperatures >260 °C in air) relative to poly(GMA), while retaining similar glass transition temperatures (~ 65 °C) and surface energies (~ 53 mJ m−2); thus, these materials could be substituted for poly(GMA) and enable use in higher‐temperature applications. © 2020 Wiley Periodicals, Inc. J. Polym. Sci.2020,58, 673–682

    more » « less

    Hypervalent iodine(III) compounds with tetrazole ligands C6H5I(N4CR)2(R  CH3, C6H5, 4‐CH3C6H4) reacted, in the presence of elemental iodine, with the double bonds in cis‐1,4‐polyisoprene (polyIP) to afford iodo‐tetrazolylated polymers. The alkyl‐iodide groups in the products of the polyIP functionalization were utilized as macro chain‐transfer agents for the iodine‐transfer polymerization of methyl methacrylate, which yielded brush polymers with well‐defined poly(methyl methacrylate) side chains. In addition, the iodo‐tetrazolylated polymers were reacted with NaN3in DMF at room temperature, and it was noticed that, in addition to nucleophilic substitution, elimination reactions took place. However, the presence of azide groups was taken advantage of and successful click chemistry‐type of grafting‐onto reactions were carried out with alkyne‐capped poly(ethylene oxide) in the presence of CuBr andN,N,N′,N″,N″‐pentamethyldiethylenetriamine. The thermal decomposition of both the iodo‐tetrazolylated and the azido‐tetrazolylated polymers was exothermic, especially for the latter materials. © 2019 Wiley Periodicals, Inc. J. Polym. Sci.2020,58, 172–180

    more » « less

    Copper‐catalyzed azide‐alkyne cycloaddition polymerization (CuAACP) of AB2monomers demonstrated a chain‐growth mechanism without any external ligand because of the complexation ofin situformed triazole groups with Cu catalysts. In this study, we explored the use of various ligands that affected the polymerization kinetics to tune the polymers’ molecular weights and the degree of branching (DB). Eight ligands were studied, including polyethylene glycol monomethyl ether (PEG350,Mn= 350), tris(benzyltriazolylmethyl)amine (TBTA), 2,6‐bis(1‐undecyl‐1H‐benzo[d]imidazol‐2‐yl)pyridine (Py(DBim)2), 2,2′‐bipyridyl (bpy), 4,4′‐di‐n‐nonyl‐2,2′‐bipyridine (dNbpy),N,N,N′,N″,N″‐pentamethyldiethylenetriamine (PMDETA),N,N,N′,N″,N″‐penta(n‐butyl)diethylenetriamine (PBuDETA), andN,N,N′,N″,N″‐pentabenzyldiethylenetriamine (PBnDETA). All ligands except PEG350exhibited stronger coordination with Cu(I) than the polytriazole polymer, which freed the Cu catalyst from polymers and resulted in dominant step‐growth polymerization with simultaneous chain‐growth feature. Meanwhile, the use of PEG350ligand retained the confined Cu in the polymer, demonstrating a chain‐growth mechanism, but lower polymer molecular weights as compared with the no‐external‐ligand polymerization. Results indicated that aliphatic substituent groups on ligands had little effect on the molecular weights and DB of the polymers, but rigid aromatic substituent groups decreased both values. By varying the ligand species and amounts, hyperbranched polymers with DB value ranging from 0.53 ([TBTA]0/[Cu]0= 5) to 0.98 ([PMDETA]0/[Cu]0= 2) have been achieved. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2018,56, 2238–2244

    more » « less

    Neodymium‐based catalysts coordinated with phosphate ligands (NdCl3·3L), where L = triethyl phosphate (TEP) or tris(2‐ethylhexyl) phosphate (TEHP), were synthesized. The ring‐opening polymerizations (ROP) of ɛ‐caprolactone (ɛ‐CL) with these catalysts in the presence of benzyl alcohol initiator were performed, yielding polymers with well‐defined molecular weights and relatively narrow polydispersity index (PDI = 1.22–1.65).In situNMR analysis of the reaction between NdCl3·3TEP and benzyl alcohol indicated that ROP proceeds through a coordination‐insertion mechanism. The end groups of the resultant polymers were determined using MALDI‐ToF mass spectrometry and NMR spectroscopy. Thequasi‐livingnature of this catalytic system was demonstrated by kinetic studies and the successful synthesis of the block copolymer poly(ɛ‐caprolactone)‐block‐poly(l‐lactide) by sequential monomer addition. Kinetic studies revealed that the catalyst with the bulkier TEHP ligand increased the rate of ROP of ɛ‐CL as compared to the TEP ligand. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2018,56, 1289–1296

    more » « less

    Carbohydrates are the fundamental building blocks of many natural polymers, their wide bioavailability, high chemical functionality, and stereochemical diversity make them attractive starting materials for the development of new synthetic polymers. In this work, one such carbohydrate,d‐glucopyranoside, was utilized to produce a hydrophobic five‐membered cyclic carbonate monomer to afford sugar‐based amphiphilic copolymers and block copolymers via organocatalyzed ring‐opening polymerizations with 4‐methylbenzyl alcohol and methoxy poly(ethylene glycol) as initiator and macroinitiator, respectively. To modulate the amphiphilicities of these polymers acidic benzylidene cleavage reactions were performed to deprotect the sugar repeat units and present hydrophilic hydroxyl side chain groups. Assembly of the polymers under aqueous conditions revealed interesting morphological differences, based on the polymer molar mass and repeat unit composition. The initial polymers, prior to the removal of the benzylidenes, underwent a morphological change from micelles to vesicles as the sugar block length was increased, causing a decrease in the hydrophilic–hydrophobic ratio. Deprotection of the sugar block increased the hydrophilicity and gave micellar morphologies. This tunable polymeric platform holds promise for the production of advanced materials for implementation in a diverse range of applications. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2019,57, 432–440

    more » « less