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This review summarizes the successful development and commercialization of a superabsorbent polymer (SAP) using iodine transfer polymerization (ITP). We found that the overall absorption performance of the SAP was improved by applying ITP and that this improvement was related to the homogenization of the polymer network. This innovation enables the quick response to diversified customer needs in the diaper industry. We believe that this achievement will contribute to improving the quality of life of people around the world.
Photopolymerization of dodecyl acrylate was conducted using methyl phenylglyoxylate as an initiator. Most polymers had either an acryloyl group or a benzoyl group at one of the chain ends. We investigated the initiation pathways and found out that methyl phenylglyoxylate initiated photopolymerization only by Norrish type II processes.
The dilute solution properties of poly(d,l-lactide)s (PDL50) with a weight-averaged molar mass (Mw) ranging from 0.154 × 104 to 75.7 × 104 g mol−1 are thoroughly studied in tetrahydrofuran at 25 °C by static light and small-angle X-ray scattering and intrinsic viscosity ([η]) measurements. The Mw dependences of 〈S2〉z1/2 and [η] are quantitatively described by the wormlike cylinder with stiffness parameter λ−1 = 2.9 nm, indicating that the PDL50 chain behaves as a typical flexible polymer but is essentially 1.6−2.1 times stiffer than polystyrene and poly(methyl methacrylate).
This work presents a method on tailoring open pores on the patterned surface of polyethersulfone membrane prepared by the phase separation micromolding. By modifying both the thermodynamics of the casting solution and the dynamics of solvent/nonsolvent demixing, micropatterned membrane with average surface open pores in the diameter of 1095 nm and porosity as high as 31.4% was achieved. The size and number of pores were different depending on their locations on the patterned surface, which was caused by different solvent/nonsolvent demixing dynamics resulting from the physical discontinuity of micro-patterned membranes.
The thermocompression bonding of conductive polymer films was investigated to achieve a flexible wiring and packaging technique for flexible electronics. Conductive polymer poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) films were successfully bonded together by thermocompression, especially through surface activation treatment using ultraviolet light irradiation. After thermocompression, the PEDOT:PSS films maintained their ohmic electrical conductivity even through the adhered interface. The surface state analysis of the PEDOT:PSS indicated that the oxidized species were generated after the surface activation process. These chemical species can interact each other and provide robust bonding interfaces.
The interfacial adhesion between olefinic double bond- or hydroxyl-terminated telechelic polypropylenes (PPs) and carbon fibers was studied to determine the potential of the telechelic PPs as a candidate for PP matrix resin-coupling agents for carbon fiber-reinforced PP composites. The hydroxyl-terminated PP showed higher interfacial shear strength than that of commercial PP and olefinic double bond-terminated PP. The hydroxyl-terminated PP could be used as a novel coupling agent of the PP matrix.
The correlation between mechanical properties and structural changes upon uniaxial stretching was studied by atomic force microscopy observations and two-dimensional small-angle X-ray scattering measurements. For this purpose, coated layers composed of di- and tri-block copolymer blends were prepared by solution coating at different drying temperatures. The packing regularity of spherical microdomains in the stretching direction was enhanced with stretching. We could correlate fracture of the block copolymer film having spherical microdomains with the completion of stretching-induced ordering of spheres in the stretching direction, which sensitively depended on the drying temperature.
Polymeric micelles based on amphiphilic poly(ethylene oxide)-b-poly(ε-caprolactone)-b-poly(ethylene oxide)(PEO-b-PCL-b-PEO) triblock copolymers improved the solubility of caffeic acid phenethyl ester (CAPE) in aqueous media. Further on, the grafting of pendant cinnamyl moieties to the PCL block enhanced the compatibility between CAPE and the micellar core, thus increasing the encapsulation efficiency and reducing the burst release effect as compared to those of micelles with an unmodified PCL core.
A cyclic block copolymer allows feasible fabrication of porous films through designed interaction between its macromolecular arms. The morphology of pores is directly determined by the structural features of the block copolymer and can be easily tuned by modification of the length of its ring and arms.
In this study, we synthesized and characterized cyclodextrin-based nanoparticles (CDNPs) by polyaddition reactions using epichlorohydrin and three different type of CDs (α-, β-, and γ-CD). We found that cyclodextrin tended to cover surface of our nanoparticles; while epichlorohydrin network enlarged when weight ratio of epichlorohydrin/cyclodextrin increased. Our CDNPs demonstrated a very high loading ratio against α-mangostin (MGS), and getting close to 1:1 ratio.
Gels containing the medicinal ingredients of licorice were formed by dissolving herbal medicinal plants into a biocompatible zwitterionic cellulose solvent and successive precipitation. The licorice gels gradually released glycyrrhizic acid, the main medicinal ingredient in licorice, within 3 h. Although the licorice gels were mechanically weak, the gel strength was improved just by the addition of cellulose during the preparation of the gels.
