Search

A new accepter unit, 2,3-didodecyl-6,7-difluoroquinoxaline, was prepared and utilized for the synthesis of electron acceptor–donor–acceptor materials for organic solar cells. 2,3-Didodecyl-6,7-difl...

In this study, we focused on the manufacturing of void-free composites of electrospun nylon 6 nanofibers as reinforcement for the poly(vinyl alcohol) (PVA) matrix. PVA solution was introduced into ...

A simple modification of cellulose nanocrystals (CNC) was intended for preparing ameliorated nanofillers for UV-curable PUA coatings. This modification was carried out by dispersing CNC in DMSO wit...

A series of novel structured latex particles with semi-interpenetrating polymer network (IPN) of glassy styrene-acrylonitrile copolymer (SAN) cores and rubbery polyurethane (PU) shells were synthes...

Since a production line for 3D printing is easier to change a product model than that for traditional manufacturing one, 3D printing technology is developing and growing faster than most other tech...

In this study, we synthesized non-isocyanate poly(hydroxyurethane)s (NI-PHUs) via the polyaddition of bis(cyclic carbonate)s and diamines. Bis(cyclic carbonate)s were prepared by reacting resorcino...

Recently, conventional solvent-typed polyurethanes are subject to many regulations due to emission of organic volatile compounds(VOCs) and researches have been focused on eco-friendly waterborne po...

The degradability of degradable polymers is the most important property to determine the lifetime of commercial applications. To control degradation rate and thermal properties, enantiomeric block ...

Although a photo curing is more efficient in terms of time, solvent, and cost than a thermal one, photo-curable coatings require low viscosity and fast curing speed due to workability and time savi...

Over the past few years, silicone-based polymers have been widely studied because silicone shows unique surface properties, such as hydrophobicity, film formability, etc and then silicone-based com...

We designed and synthesized two novel low band gap small molecule donors (M1 and M2) that consist of benzo[1,2-b:4,5-b′]dithiophene as the electron-rich core and 6,7-difluoroquinoxaline as the elec...

Synthesis of zeolitic materials with coal fly ash (CFA) using a fusion/hydrothermal method was performed by various crystallization parameters such as aging time, crystallization time, crystallizat...

Since most of the coatings have been prepared by organic solvents, there are many regulations because of the environmental and health hazards caused by volatile organic compounds. As an alt...

Polyurethane- and polysiloxane-based coating agents are widely used in automobiles and electronic devices for sealing. To study a component which affects their surface properties, polyureth...

To develop carbon dioxide-reducible polymeric materials, triblock copolymers (PLA-polyester-PLA) of enantiomeric lactides and biopolyester diol, were synthesized by the ring-opening polymer...

Polyurethane is one of the most versatile polymeric materials and is found just about everywhere in modern life including coatings and adhesives in electronics and automobile interior. Howe...

In order to develop ultraviolet (UV)-curable coatings applicable to pre-coated metal (PCM), organic-inorganic hybrid UV curable polyurethane (PU)-acrylates were prepared using cage type met...

Polyaspartic coating is well known as one of popular eco-friendly coatings because of non VOC and excellent mechanical properties such as fast curing, abrasion resistance, chemical resistan...

Typical light stabilizers absorb and block UV rays in the wavelength range of 300-380 nm region. This range overlaps with the UV region, necessary to cure UV-curable coating. By overlapping...

Magnetic nanoparticles containing mesoporous carbon materials have been synthesized via an one-pot strategy associated with a direct carbonization process from resol, metal ion sources (Co(...

The value of the critical surface tension(γc.0) of the polyolefin part calculated by Zismann plot was 26.1 dyne/cm. The surface state and the γc,0 of the polyolefin part were changed by sol...

The aim of the present study was to evaluate the efficacy of the inverted internal limiting membrane (ILM) flap technique that involved the use of a perfluorocarbon liquid (PFCL) bubble for the selective prevention of indocyanine green (ICG) staining of the parts of the inverted flap in contact with the retinal pigment epithelium for large macular hole (MH) closure.This retrospective, interventional, comparative study included 26 patients with idiopathic large MHs (minimum diameter, 400 µm) who underwent vitrectomy using the inverted ILM flap technique with conventional ILM staining with ICG (n = 14, Group 1) or PFCL-mediated selective ILM staining with ICG (n = 12, Group 2). The hole closure rate, best-corrected visual acuity (BCVA), and optical coherence tomography findings were analyzed at baseline and 1, 3, and 6 months after surgery in both groups.Hole closure was achieved in all the eyes. BCVA significantly improved after surgery in both groups (p 0.001 for both groups), although Group 2 exhibited significantly better values at 3 and 6 months after surgery (p = 0.008 and 0.001 at 3 and 6 months, respectively). The sizes of ellipsoid zone defect significantly decreased after surgery in both groups (p 0.001 relative to the baseline width in both groups), and it was significantly smaller in Group 2 than in Group 1 at 3 (p = 0.006) and 6 (p = 0.001) months after surgery.The findings of this study suggest that recovery of the photoreceptor layers and, consequently, the postoperative VA are better with the inverted ILM flap technique employing PFCL-mediated selective ILM staining with ICG than with the technique employing conventional ILM staining with ICG methods for patients with large MHs.

To develop a halogen-free polyurethane adhesive for thermoplastic nonpolar polyolefins, polyurethanes were synthesized by using polyester polyol, polyolefin polyol, 4,4′-dicyclohexylmethane diisocy...

A facile route for grafting poly(ionic liquid)s (PILs) on to the surface of multi-walled carbon nanotubes (MWNTs) was demonstrated via Diels-Alder (DA) “click” reaction. Firstly, block copolymers o...

Eco-friendly water-repellent UV-curable polyurethane acrylates (PUA) with fluorine groups were synthesized from H12MDI which is excellent yellowing resistance and water resistance, polycarbonate di...

The UV-curable coatings are emerging as new environmental friendly coating technology for replacement of solvent-based ones. UV-curable polyurethane acrylate oligomers were newly synthesized using ...

In this study, chloroprene rubber (CR) /silica nanocomposites prepared by dispersing nanosilica in CR was applied as a primer and its adhesion properties were examined. The structure of CR/silica n...

For an environmentally-friendly coating, waterborne UV-curable poly-urethane acrylates were synthesized with different mixing ratios of 4,4-methylene dicyclohexyl diisocyanate (H12MDI) and ...

To expand their applications, UV-curable coatings for pre-coated metal (PCM) require high flexibility and stiffness for formability and hardness, respectively. However, it is difficult to satisfy b...

Although polyurethane (PU)- and polysiloxane-based coating agents find wide applications in electronics and automotive industries (e.g., for sealing), their full potential can be realized only base...

The magnesium oxide (MgO) nanoparticles with the morphologies of globular agglomerates were synthesized from a seawater bittern by a wet decarboxylation/precipitation method. The effect of the synt...

Among the curing hardeners for powder coating, β-hydroxyalkylamide is widely used due to its easy handling, excellent exterior durability, good mixing with other chemicals, flexibility, hardness, a...

To improve the mechanical and thermal properties of polyurethane, two prepolymers, polyurethane acrylate (PUA) and epoxy acrylate (EPA) which have acrylate-ended groups, were synthesized. The obtained prepolymers were homogeneously mixed with various compositions and cured by UV. After UV curing, the properties of PU/EP copolymers were investigated by using Fourier-transform infrared spectroscopy, universal testing machine, dynamic mechanical thermal analysis and thermogravimetric analysis. The thermal and tensile properties of PU/EP copolymers gradually increased with the amount of EP due to the intermolecular interaction whereas their elongation properties decreased. These results indicate that the copolymerization of PU with EP could control their mechanical properties.

The hybrid material of magnetic graphene oxide (MNPs/GO) was prepared with a facile route and adsorption properties for removal of methylene blue (MB) were investigated. Initially, the surface of m...

In this study, a green chemistry method is reported for the synthesis of Ag2O nanoparticles with the utilization of starch molecules as a stabilizing agent. In particular, by simply adjusting the concentration of starch in the reaction media, the structure of A2O nanoparticles can be engineered in disc and faceted shapes, which has been analyzed by transmission electron microscopy, UV-Vis spectroscopy, and X-ray diffraction technique. In addition, antibacterial activity of the prepared Ag2O nanoparticles had been evaluated against food poisoning and pathogenic bacteria.

To develop carbon dioxide (CO2)-reducible polymeric materials, block copolymers (PLA-PEC-PLA) of CO2-reducible polymers, poly(lactide) (PLA) and poly(ethylene carbonate) (PEC) were synthesized by the ring-opening polymerization of lactide in the presence of PEC diol using stannous octoate. Differential scanning calorimetry and contact angle measurements showed that the incorporation of the PEC block decrease the crystallinity of PLA and increases the hydrophilicity and flexibility due to its compatibility. The enzymatic degradation in Tris-HCl buffer containing proteinase K showed that the degradation rate of L-PLA-PEC-L-PLA was faster than that of L-PLA due to the decreased crystallization and increased hydrophilicity after copolymerization as well as degradation of PEC.

Two type of triblock copolymers [poly(l-lactide)-b-perfluoro polyether-b-poly(l-lactide) (fluoro l-PLA) and poly(d-lactide)-b-perfluoro polyether-b-poly(d-lactide) (fluoro d-PLA)] (fluoro PLAs) were synthesized by ring-opening polymerization. The synthesized triblock copolymers showed more hydrophobic properties than pristine l-PLA due to the perfluoro polyether (PFPE). To control the surface properties, the blends were prepared by mixing fluoro PLAs with l-PLA. The degradation rates of the fluoro PLAs/l-PLA blends were retarded due to the surface segregation of PFPE which has lower surface energy. In case of the fluoro d-PLA/l-PLA blends, however, the stereocomplex formation between the l-lactide and d-lactide sequences enhanced the thermal and enzymatic stabilities of l-PLA. As a result, the biodegradability of l-PLA can be controlled by copolymerization or the formation of a stereocomplex.