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Novel amphiphilic poly(2-oxazoline)s bearing l-prolinamide moieties at the alkyl side-chain termini were designed and synthesized by a bottom-up protocol. These polymers formed micelle-type assemblies with a size of 10–30 nm in water, in which the majority of prolinamide active groups was tucked into the hydrophobic inner core. As a nanoreactor, the micellar systems were successfully applied to the...
Graft-copolymerization of vinyl monomer containing silica precursor, p-styryltrimethoxysilane, onto natural rubber microparticles was performed in latex stage to form three-dimensional networks of nanosilica. After the latex was cast into a film, morphology observation by transmission electron microscopy showed that the natural rubber microparticles were dispersed in organic–inorganic nanomatrix consisting...
The development of new urethane based poly(ionic liquids) (PILs) is a promising solution to address CO2 capture. The obtainment of low cost polyurethane based PILs using different ionic liquids cations fosters the emergence of new materials for CO2 capture. The synthesized PILs were characterized by GPC, FTIR, NMR, DSC, TGA, DMTA and AFM. CO2 sorption capacity was gravimetrically assessed in a magnetic...
Oriented polystyrene (PS) has attracted attention due to its capability of sequential self-folding behaviors by infrared (IR) light heating. It has been seen that temporal changes of the shape and properties of PS are affected by its pre-defined molecular structure. In this study, full atomistic molecular dynamics (MD) simulations are carried out to study the effect of initially applied strain on...
In this work, the photo-reversible [4πs+4πs] cycloaddition reaction of anthracene moieties is employed to impart wavelength dependent properties into carboxylated nitrile butadiene rubber networks. Crosslinking of the side chain functionalized rubber is achieved by UV induced dimerization of pendant anthracene groups at wavelengths above 300 nm whilst a subsequent deep UV exposure (λ = 254 nm) results...
To determine the processing temperature of a representative thermotropic liquid crystalline polymer (TLCP) in the super-cooled state, small amplitude oscillatory shear (SAOS), the startup of shear flow and differential scanning calorimetry (DSC) measurements were performed. Good agreement on the onset crystallization temperature was obtained from the SAOS and the startup of shear flow. Compared with...
We have an ongoing interest in the design and control of helical conformation of water-soluble meta-linked poly(phenylene ethynylene)s (PPEs) and the further development of novel functional materials. Four cationic meta-linked PPEs (P1′-P4′) were synthesized to study the influence of differences in the backbone and side chain structure on their conformations. For P1′ and P4′ without side chains on...
Three dimensional (3D) electric conducting porous structures are a promising platform that could be utilized in emerging 3D structural electronics, energy storage systems, and biomedical applications. A poly(3,4-ethylenedioxythiophene)/silica (PEDOT/SiO2) composite with foam-like conducting open skeletal structures and pore sizes exceeding 100 μm is presented. A two-step procedure was used to prepare...
The crystallization kinetic of neat and nucleated heterophasic isotactic propylene(ethylene-propylene) copolymer (iPP-EPC) was analyzed by fast scanning chip calorimetry. On cooling neat iPP-EPC shows two exothermic events, one related to the solidification of the iPP component followed by the crystallization of the polyethylene (PE) part in the copolymer. The effect of the type of nucleating agent...
It has become increasingly common to use atomic force microscopy measurements to probe mechanical properties at the nano-micro level. The data obtained from these measurements, however, must be subjected to specific models for deconvolution of the effect of the probe's tip size and shape. While analytical models have been developed to assist in this endeavor, a thorough understanding of the limits...
For the first time, conventional and controlled miniemulsion polymerization of vinyl acetate (VAc) was performed using gamma radiation as alternative source of initiation. Reversible addition-fragmentation chain transfer/macromolecular design via interchange of xanthates (RAFT/MADIX) technique was applied to control the polymerization process. For this purpose, S-2-cyano-2-propyl-O-ethyl xanthate...
A series of salicylbenzoxazole pro-ligand 2-(5-X-benzoxazol-2-yl)-6-R1-4-R2-phenol, L1H-L4H were subjected to reaction with titanium, zirconium and hafnium alkoxides. The substituents (R1, R2, X) present in the pro-ligand back bone are (H, H, H) for L1H; (H, H, Cl) for L2H; (Br, Br, H) for L3H; and (Cl, Cl, H) for L4H. The mononuclear Ti complexes, 1a-4a of [M(L)2(OiPr)2] formulation were prepared...
The effect of molecular weight (MW) and comonomer content (CC) on the catalytic hydrogen-deuterium exchange process (CHDEP) in a series of polyethylenes has been studied using a band filter based SEC-IR method. CHDEP permits deuterium labeling of polyolefins prepared by any synthetic route, a major advantage over the traditional method of polymerizing deuterated monomers. However, incompleteness in...
In this work, hydroxylated HPEEK [poly (ether ether ketone)], which is miscible with the pre-polymer (epoxy), was covalently grafted on to carboxyl functionalized multiwall carbon nanotubes (a-MWNTs) to tailor the interface between MWNTs and the host resin (epoxy). The grafted MWNTs were systematically characterized using spectroscopic techniques. The epoxy composites with a-MWNTs and HPEEK grafted...
Branched PEI is adsorbed from 2 mmol/L solution onto a negatively charged DMPG monolayer at the air/water interface from a solution with 2 mmol/L FeSO4. With X-ray reflectivity it is found that the adsorbed PEI layer contains iron. Compared to PEI adsorbed from clean water the thickness is increased by a factor three to four. It is suggested that cooperative bonds stabilize iron ions within the PEI...
Semi-crystalline polylactide (PLA)/polyolefin multi-component blends were used as precursors for the generation of a new class of micro-cellular polymers. Either a polypropylene-based elastomer (PBE) or polypropylene (PP) homopolymer were utilized as dispersed phases at the 10 wt% level. An epoxy-functionalized terpolymer (PEGMMA) was introduced (1 wt%) as a reactive compatibilizer to reduce the dispersed...
This paper investigates the porphyrin de-aggregation in a set of guest-host films, prepared by spin coating, in a series of poly(n-alkyl methacrylate)s matrices. UV–Vis optical absorbance and steady-state photoluminescence spectroscopy in association with the fluorescence lifetime imaging technique (FLIM) helped to characterize the film blends. All the PnMA matrices de-aggregated the porphyrin molecules...
MXenes represent a new family of 2D transition metal carbides and/or carbides that has attracted a great deal of attention in various applications because of their unique electrical, thermal, and mechanical properties. In this work, we report on the structure and crystallization behavior of poly(ethylene oxide)(PEO)/MXene nanocomposites. MXene Ti3C2Tx (where T is a surface termination) was synthesized...
Unwanted shrinkage behaviors or failure in structural functions such as mechanical strength or deformability of polymeric products related to their thermomechanical history are a major challenge in production of plastics. Here, we address the question whether we can turn this challenge into an opportunity by creating defined thermomechanical histories in polymers, represented by a specific morphology...
Firstly, specific aging and rejuvenating treatments are applied to PHB samples. This enables to clarify the roles of secondary crystallization and of physical ageing on PHB embrittlement over time. The reversibility of physical ageing and irreversibilty of secondary crystallization are demonstrated after annealing. Secondly, we focus on the effect of addition of plasticizer on the microstructure of...
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