Yu, Duk Man; Smith, Darren M.; Kim, Hyeyoung; Rzayev, Javid; Russell, Thomas P.
Two-Step Chemical Transformation of Polystyrene-block-poly(solketal acrylate) Copolymers for Increasing ?
We investigated the two-step chemical transformation of a series of symmetric poly(styrene-b-solketal acrylate) (PS-b-PSA) copolymers with varying molecular weights from 1900 to 27?300 g/mol (13 ? N ? 194) synthesized by sequential atom transfer radical polymerization. Through acid-catalyzed hydrolysis, the PSA block is converted into poly(glycerol acrylate) (PGA), which subsequently…
Multi-scale modelling approach to homogenise the mechanical properties of polymeric closed-cell bead foams
Gebhart, Thomas M. J.; Jehnichen, Dieter; Koschichow, Roman; Müller, Michael; Göbel, Michael; Geske, Vinzenz; Stegelmann, Michael; Gude, Maik
The complex mechanical deformation behaviour of closed-cell foams is governed by morphological and physical properties such as cell structure and crystallinity. In this study, the micro-, meso- and macroscopic scale of commercially available bead foam was analysed. Statistical distribution of the cell structure including cell size, wall thickness and shape…
Tuning Mechanical Properties of Biobased Polymers by Supramolecular Chain Entanglement
Lamm, Meghan E.; Song, Lingzhi; Wang, Zhongkai; Rahman, Md Anisur; Lamm, Benjamin; Fu, Lin; Tang, Chuanbing
A variety of biobased polymers have been derived from diverse natural resources. However, the mechanical properties of some of these polymers are inferior due to low chain entanglement. We report a facile strategy termed supramolecular chain entanglement, which utilizes supramolecular interactions to create physical cross-linking and entanglements for polymers with…
Investigation of the internal structure of thermoresponsive diblock poly(2-methyl-2-oxazoline)-b-poly[N-(2,2-difluoroethyl)acrylamide] copolymer nanoparticles
Babuka, David; Kolouchova, Kristyna; Hruby, Martin; Groborz, Ondrej; Tosner, Zdenek; Zhigunov, Alexander; Stepanek, Petr
The poly(2-methyl-2-oxazoline)-b-poly self-assembled nanoparticles show great potential in biological applications as, e.g., 19F MRI tumour diagnostic agents. As such their internal structure needs to be thoroughly investigated while the results also help to understand temperature-dependent self-assembly behaviour of copolymers comprised of the hydrophilic and
Tunable Fluorophobic Effect Determines Nanoparticle Dispersion in Homopolymers and Block Polymers
Marsh, Zachary M.; Blom, Douglas A.; Stefik, Morgan
The controlled placement of nanoparticles (NPs) within homopolymers and block polymers is of broad interest for functional nanomaterials. This manuscript focuses on small molecule-stabilized NPs that bring a large fraction of functionality. For such NP mixtures with block polymers, the overwhelming focus to date has been the use of attractive…
Enhanced Conductivity via Homopolymer-Rich Pathways in Block Polymer-Blended Electrolytes
Morris, Melody A.; Sung, Seung Hyun; Ketkar, Priyanka M.; Dura, Joseph A.; Nieuwendaal, Ryan C.; Epps, Thomas H.
The optimization of ionic conductivity and lithium-ion battery stability can be achieved by independently tuning the ion transport and mechanical robustness of block polymer (BP) electrolytes. However, the ionic conductivity of BP electrolytes is inherently limited by the covalent attachment of the ionically conductive block to the mechanically robust block,…
Comparative Study of Direct Compounding, Coupling Agent-Aided and Initiator-Aided Reactive Extrusion to Prepare Cellulose Nanocrystal/PHBV (CNC/PHBV) Nanocomposite
Zheng, Ting; Clemons, Craig M.; Pilla, Srikanth
Three compounding methods were compared to determine their effects on the organization of the interphase in nanocomposites of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and cellulose nanocrystals (CNCs) processed via (1) direct compounding, (2) reactive extrusion using a coupling agent (PHBV-g-GMA), or (3) reactive extrusion using a peroxide free-radical initiator (dicumyl peroxide,
Fast Photochromic Dye Response in Rigid Block Polymer Thermosets
Peterson, Colin; Hillmyer, Marc A.
The behavior of photochromic spiropyran (SP) dyes is greatly affected by the local environment in which they reside. Fluid microenvironments such as liquidlike polymers grant favorably fast dye decoloration whereas rigid microenvironments such as glassy polymers inhibit fast dye response. We study the use of disorganized but microphase-separated block polymer…
Improving the Hydrolysis Rate of the Renewable Poly(hexamethylene sebacate) Through Copolymerization of a Bis(pyrrolidone)-Based Dicarboxylic Acid
Noordzij, Geert J.; Roy, Manta; Bos, Natasja; Reinartz, Vincent; Wilsens, Carolus H. R. M.
In this work, we report on the synthesis of a series of polyesters based on 1,6-hexanediol, sebacic acid, and N,N’-dimethylene-bis(pyrrolidone-4-carboxylic acid) (BP-C2), of which the latter is derived from renewable itaconic acid and 1,2-ethanediamine. Copolymers with a varying amount of BP-C2 as dicarboxylic acid are synthesized using a melt-polycondensation reaction…
Structure Evolution and Deformation Behavior of Polyethylene Film during Biaxial Stretching
Chen, Qiang; Wang, Zhiwei; Zhang, Sumei; Cao, Ya; Chen, Jinyao
The structure evolution and deformation behavior of tenter-frame biaxially oriented polyethylene (TF-BOPE) films were investigated in this study. For sequential biaxial stretching, the original spherulites were broken into small pieces, and the fibrillar structure simultaneously formed during the machine direction (MD) stretching. Subsequently, the single fibrils were pulled away, and…