Polymer Chemistry

Journal: Polymer Chemistry

Abbreviation

Polym. Chem.

Publisher

Royal Society of Chemistry

ISSN

1759-9962
1759-9954

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Publications 1 - 10 of 70

3D printed elastomers with Sylgard-184-like mechanical properties and tuneable degradability
Paunović, Nevena; Leroux, Jean-Christophe; Bao, Yinyin (2022)
Polymer Chemistry
The 3D printing of biodegradable elastomers with high mechanical strength is of great interest for personalized medicine, but rather challenging. In this study, we propose a dual-polymer resin formulation for digital light processing of biodegradable elastomers with tailorable mechanical properties comparable to those of Sylgard-184
Educational series: characterizing crosslinked polymer networks
Rajawasam, Chamoni W.H.; Dodo, Obed J.; Weerasinghe, M.A. Sachini N.; et al. (2024)
Polymer Chemistry
Characterization of polymer networks presents unique challenges due to the insolubility of the materials, but this also enables characterization by new techniques that take advantage of the bulk network structure. An overview of characterization methods for polymer networks is presented, including functionality by IR, swelling and gel fraction calculations, mechanical characterization, thermal characterization, evaluation of molar masses between crosslinks and surface properties. This contribution serves as a reference for researchers aiming to evaluate network properties for the first time, or to expand the range of techniques used in network characterization.
Preparing DNA-mimicking multi-line nanocaterpillars via in situ nanoparticlisation of fully conjugated polymers
Lee, In-Hwan; Amaladass, Pitchamuthu; Choi, Inho; et al. (2016)
Polymer Chemistry
A unique hierarchical evolution from single-line nanocaterpillars to multi-line nanocaterpillars and then to multi-line nanocaterpillars bearing a few long-chain branches was demonstrated by in situ nanoparticlisation of fully conjugated poly(2,5-dihexyloxy-1,4-phenylene)-block-poly(3-methylthiophene) (PPP-b-P3MT). PPP-b-P3MTs of various block ratios were successfully synthesised by the Grignard metathesis polymerization method; moreover, these block copolymers underwent spontaneous self-assembly during the polymerization owing to the solvophobicity or strong π–π interactions of the core block, i.e. P3MT. These in situ generated PPP-b-P3MT NPs were quite different from the previously reported NPs generated from poly(2,5-dihexyloxy-1,4-phenylene)-block-polythiophene (PPP-b-PT). AFM and TEM images revealed that PPP-b-P3MTs formed single- to multi-line nanocaterpillars, whereas PPP-b-PTs only formed shorter single-line nanocaterpillars. On the basis of PXRD and UV–vis data, we speculated that this interesting morphology of multi-line nanocaterpillars, resembling duplex DNA, arose from different packing modes and crystallinity as well as improved solubility of the P3MT core compared with the NPs containing the PT core.
Absolut “copper catalyzation perfected”; robust living polymerization of NIPAM: Guinness is good for SET-LRP
Waldron, Christopher; Zhang, Qiang; Li, Zaidong; et al. (2014)
Polymer Chemistry
The controlled polymerization of N-isopropyl acrylamide (NIPAM) is reported in a range of international beers, wine, ciders and spirits utilizing Cu(0)-mediated living radical polymerization (SET-LRP). Highly active Cu(0) is first formed in situ by the rapid disproportionation of [Cu(I)(Me6-Tren)Br] in the commercial water–alcohol mixtures. Rapid, yet highly controlled, radical polymerization follows (Đ values as low as 1.05) despite the numerous chemicals of diverse functionality present in these solvents e.g. alpha acids, sugars, phenols, terpenoids, flavonoids, tannins, metallo-complexes, anethole etc. The results herein demonstrate the robust nature of the aqueous SET-LRP protocol, underlining its ability to operate efficiently in a wide range of complex chemical environments.
Hierarchical superstructures of norbornene-based polymers depending on dendronized side-chains
Kim, Dae-Yoon; Kang, Dong-Gue; Shin, Suyong; et al. (2016)
Polymer Chemistry
For understanding the self-assembly behaviors of norbornene-based main-chain polymers depending on dendronized side-chains, a series of polynorbornenes containing the programmed dendrons (AT3P and BP3P) is newly designed and successfully synthesized via ring-opening metathesis polymerization (ROMP) with high molecular weights and narrow polydispersity indices. The phase transitions and molecular packing structures of AT3P and BP3P are investigated by the combination of thermal, scattering and microscopic analyses. AT3P with flexible and hydrophobic alkyl chain dendrons forms the columnar nematic (ColN) liquid crystal (LC) phase. By introducing a rigid biphenyl mesogen and a hydrophilic triethylene oxide linker between the hydrophobic alkyl chain and the polynorbornene main-chain, a smectic A (SmA) LC phase is formed, mainly due to the nanophase separations and the strong intermolecular interactions between the biphenyl mesogens. This study reveals that the hierarchical superstructures of norbornene-based polymers can be precisely controlled by tuning the chemical structures and the physical interactions of side-chain pendants.
Arginine-specific protein modification using alpha-oxo-aldehyde functional polymers prepared by atom transfer radical polymerization
Gauthier, Marc A.; Ayer, Maxime; Kowal, Justyna; et al. (2011)
Polymer Chemistry
A facile synthetic strategy to polysiloxanes containing sulfonyl side groups with high dielectric permittivity
Dünki, Simon J.; Cuervo-Reyes, Eduardo; Opris, Dorina M. (2017)
Polymer Chemistry
The chemical modification of polymers with lateral polar groups increases their dielectric permittivity above the glass transition temperature, making them attractive materials for dielectric elastomer actuators. Despite the large dipole moment of the sulfonyl moiety, its usefulness as a substituent in high permittivity polysiloxanes has not been explored so far. This work explores two post-polymerization synthetic strategies to reach such a goal, namely the oxidation of the thioether groups present in polysiloxanes which carry thioether side groups at every repeat unit and the modification of the vinyl groups of poly(methylvinylsiloxanes) with sulfonyl groups via thiol–ene chemistry. While both strategies in principle work, the oxidation of the thioether groups results in an undesired shortening of the polysiloxane chains. In contrast, the thiol–ene reactions give the target polymer in a clean and highly efficient process. For this reason the access to two sulfonyl containing thiols, to be employed in the thiol–ene reaction, was improved to the degree that they are now available on the 50 g scale as pure compounds. The sulfonyl content of the polysiloxanes was systematically varied by the use of two different thiols in the thiol–ene post-polymerization modification, one of which carried the sulfonyl group, the other a (dummy) butyl group instead. The prepared polymers were characterized by NMR, DSC, TGA, GPC, and impedance spectroscopy. All polymers show glass transition temperatures below room temperature. Dielectric permittivity measurements at room temperature show that the permittivity of the polymers at the frequency with minimal losses can be fine-tuned from about 5 up to 22.7. Because of their high dielectric permittivity, low glass transition temperatures, and easy and scalable synthesis from cheap materials, these novel polymers are attractive components for high permittivity elastomers to be employed in actuators, capacitors, and flexible electronics.
The influence of surface grafting on the growth rate of polymer chains
Kang, Chengjun; Crockett, Rowena; Spencer, Nicholas D. (2016)
Polymer Chemistry
Importance of choosing the right polymerization method for in situ preparation of semiconducting nanoparticles from the P3HT block copolymer
Lee, In-Hwan; Choi, Tae Lim (2016)
Polymer Chemistry
The solution-processed self-assembly of conjugated block copolymers has been a useful strategy to produce various semiconducting nanostructures that can provide a pre-organized charge-transporting channel with high charge-carrier mobility. However, previously reported conjugated block copolymer self-assembly methods required post-synthetic treatments such as dialysis, selective solvent additions, temperature modulation, or long-time aging. Moreover, due to the relatively weak driving forces for self-assembly, the resulting nanostructures proved to be fragile when subjected to external stimuli such as heat and mechanical force. To overcome these issues, we have developed a step-economical direct self-assembly process, termed the ‘in situ nanoparticlization of conjugated polymers’ (INCP), which utilizes the extremely strong π–π interactions of insoluble blocks containing a conjugated polymer without side chains to drive the self-assembly. Previously, we successfully demonstrated in situ nanoparticlization of fully conjugated block copolymers containing poly(para-phenylene) and poly(3-(2-ethylhexyl)thiophene) as the shell, but their electronic application was rather limited, mainly because of the low conductivity of the synthesized shell. Thus, to enhance the conductivity of the nanostructures, the most widely used conjugated polymer in the field of organic electronics, poly(3-hexylthiophene) (P3HT), should be introduced to the design of INCP. Herein, we report the formation of various nanostructures from P3HT-b-polythiophene (PT) depending on the polymerization protocols. Initially, INCP via conventional Kumada catalyst-transfer polycondensation (KCTP) produced irregular and highly branched nanostructures. On the other hand, conducting INCP employing a more precise synthesis, externally initiated KCTP, afforded better well-defined nanoparticles such as one-dimensional (1D) rods and long-branching nanoparticles because this method produced diblock copolymers with the highest purity, free from triblock (PT-b-P3HT-b-PT) defects. Overall, in situ self-assembly of P3HT-b-PT provided a simple and step-economical way to produce various semiconducting nanoparticles. In addition, this study reconfirms that precise control of block copolymer synthesis on the molecular level (a first level of control) promotes a more controlled INCP, and its resulting nanostructures (a second level of control).
RAFT synthesis of poly(vinylpyrrolidone) amine and preparation of a water-soluble C-60-PVP conjugate
Aroua, S.; Tiu, E.G.V.; Ayer, M.; et al. (2015)
Polymer Chemistry

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Journal: Polymer Chemistry

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