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The functional properties of P(VDF-co-TrFE) are strongly dependent on its structure, which, in turn, depends on processing conditions applied. In this work we investigate the P(VDF-co-TrFE) processing-structure-function relationships, in order to find the thermal conditions that result in optimum ferroelectric performance in thin film configuration. Our results show that annealing temperature affects...
Several bio-based polyhydroxyls are successfully synthesized by using succinic acid, obtained via Arundo donax fermentation and characterized by 1H NMR, GPC, and FT-IR analyses. Furthermore, the bio-based polyhydroxyls, consisting of a wide spectrum of compounds in terms of chemical structure and molecular weight, are used as substitute of conventional polyol in the formulations of Polyurethane and...
Molecular bottlebrushes (MBBs) with a hydrophobic core and a hydrophilic shell may exist as well-defined unimolecular nanoparticles in water. However, they may also aggregate to form large particles if the structure of the hydrophilic and hydrophobic segments fail to be rationally controlled. Herein, a series of core-shell amphiphilic MBBs with a poly (ε-caprolactone) (PCL) backbone bearing two block...
Polymorphic transformation from the form II to form I crystal was investigated for isotactic polybutene-1 (PB) and butene-1/ethylene copolymers (PBE) with differential scanning calorimetry (DSC) and dielectric response spectroscopy (DRS). DRS detected the so-called α relaxation of segments within the amorphous phase, and DSC traced a degree of form II to I transformation with time. It turned out that...
The novel poly(hydroxy-p-phenylenebenzobisoxazole) (HPBO) was synthesized by different polymerization routes, including hydroxy-orderly distributed polymer (ord-HPBO) and hydroxy-randomly distributed polymer (ran-HPBO). Surface elemental composition, thermal stability, intrinsic viscosity, UV resistance, surface morphology, mechanical and interfacial properties of HPBO fiber were investigated. ATR-FTIR...
Manipulating the sub-units of conjugated co-polymers was a convenient and promising strategy for developing novel functional materials. Here a soluble alternating copolymer (P-Boc) consisted of 9,9-dialkylfluorene and 1,4-diketo-2,5-di(t-butoxycarbonyl)-3,6-diphenyl-pyrrolo[3,4-c]-pyrrole was designed and synthesized. Heating the spin-coated P-Boc film could afford an insoluble polymer film (P-2H)...
Dielectric polymers can achieve large, reliable deformation in response to an external electric field and have attracted significant interest as actuators and transducers. The electromechanical performance depends on the interaction between the visco-hyperelastic behaviour of materials and the Maxwell stress caused by the electric field. However, the mechanisms of complex structures, such as a surface-treated...
This work addresses the impact of fabrication conditions (curing procedure, moisture) on the properties of a two-part polyurethane system. While Part I treats the chemical, dielectric and mechanical properties during cure and storage in dry conditions, this second part focuses on these properties, along with the caloric glass transition, in moist conditions, with moisture being introduced at different...
The current investigation was to present composite membranes with strong interfacial adhesion between top polymeric selective layer and the bottom micro-porous support layer with appropriate gas permeation behavior and practically suitable processing characteristics. To this end, a series of acrylate-terminated polyurethanes (APUs) based on poly (ethylene glycol) (PEG) with different molecular weights...
Four new partly modified membranes of novel (co)polyacetylenes having a photodegradative backbone and crosslinkable side chains showed excellent performances as oxygen permselective membranes, that is, ultrahigh oxygen permeability (PO2) with relatively high oxygen permselectivity (α = PO2/PN2). In α vs. PO2 plots, two of them showed a performance close to Robeson's upper bound 2008 and the other...
Calcium pimelate (CaPim) is known as one of the most stable and effective β-nucleating agents for isotactic polypropylene (iPP). To establish the structure-properties relationships of CaPim, the structure and corresponding β-nucleating ability of as-synthesized CaPim and CaPim annealed at temperature (Ta) varying from 130 to 330 °C were investigated. Our results revealed that as-synthesized CaPim...
N,N′-Pyromellitoyl-bis-L-(3,4-dihydroxyphenyl)alanine was synthesized, as a new diacid monomer, from condensation reaction of l-dopa and pyromellitic anhydride. Polycondensation of this chiral monomer with the commercially available 4,4′-diaminodiphenylsulfone was achieved by using triphenylphosphite, as coupling agent, and calcium chloride, as dehydrating agent, in a mixture of N-methyl-2-pyrolidone...
Dielectric elastomers (DEs) are kinds of advanced functional materials, attracting more attention due to that they can used to fabricate ingenious devices. In this work, a series of advanced DEs based on the copolymer of polyurethane (PU) and acrylate, were chemically prepared through the condensation polymerization between p (BA-HEA), the n-butyl acrylate (BA) and hydroxyethyl acrylate (HEA) copolymer...
It is stressed that the structure plays a decisive role on the property of materials. Materials generally with rigid molecular chains possess outstanding mechanical performances. However, this structure-property relationship is ambiguous in some polyimide (PI) materials. In this study, three typical homo-PI fibers, derived from pyromellitic dianhydride(PMDA)/p-phenylene diamine(PDA), PMDA/4,4′-oxidianiline...
A new building block of two-dimensional (2D) A1-π-A2 copolymers for P(dDTPz-ID) and P(dDTPz-DTBT) was designed and synthesized. Their structures have two strong acceptor units (isoindigo and benzothiadiazole derivatives) in the backbone, respectively. It displayed a benefit of A1-A2 building blocks, which is complementary and broad light absorption from 300 to 750 nm due to acceptors with different...
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