Showing papers on "Polycarbonate published in 2010"

A facile route for irreversible bonding of plastic-PDMS hybrid microdevices at room temperature

Abstract: Plastic materials do not generally form irreversible bonds with poly(dimethylsiloxane) (PDMS) regardless of oxygen plasma treatment and a subsequent thermal process. In this paper, we perform plastic-PDMS bonding at room temperature, mediated by the formation of a chemically robust amine–epoxy bond at the interfaces. Various plastic materials, such as poly(methylmethacrylate) (PMMA), polycarbonate (PC), polyimide (PI), and poly(ethylene terephthalate) (PET) were adopted as choices for plastic materials. Irrespective of the plastic materials used, the surfaces were successfully modified with amine and epoxy functionalities, confirmed by the surface characterizations such as water contact angle measurements and X-ray photoelectron spectroscopy (XPS), and chemically robust and irreversible bonding was successfully achieved within 1 h at room temperature. The bonding strengths of PDMS with PMMA and PC sheets were measured to be 180 and 178 kPa, respectively, and their assemblies containing microchannel structures endured up to 74 and 84 psi (510 and 579 kPa) of introduced compressed air, respectively, without destroying the microdevices, representing a robust and highly stable interfacial bonding. In addition to microchannel-molded PDMS bonded with flat plastic substrates, microchannel-embossed plastics were also bonded with a flat PDMS sheet, and both types of bonded assemblies displayed sufficiently robust bonding, tolerating an intense influx of liquid whose per-minute injection volume was nearly 1000 to 2000 times higher than the total internal volume of the microchannel used. In addition to observing the bonding performance, we also investigated the potential of surface amine and epoxy functionalities as durable chemical adhesives by observing their storage-time-dependent bonding performances.

Aromatic polycarbonate resin composition

Abstract: A resin composition comprising an aromatic polycarbonate resin having excellent transparency and flame retardancy The resin composition comprises 100 parts by weight of an aromatic polycarbonate resin having a branched structure with a branching ratio of 07 to 11 mol % (component A) and 0005 to 12 parts by weight of at least one flame retardant

Self cleaning TiO2 coating on polycarbonate: Surface treatment, photocatalytic and nanomechanical properties

Abstract: A developed route to form TiO 2 self cleaning coatings on polycarbonate substrates is reported. TiO 2 coatings on plastics may find widespread application in auto and construction industries if possess desired photocatalytic and mechanical properties. A chemical surface treatment method was used to create hydrophilic groups on the surface. X-ray photoelectron spectroscopy showed the treatment led to the oxidation of surface groups. TiO 2 deposition was based on wet coating using an anatase sol of TiO 2 nanoparticles of 30 nm size. The sol was synthesized using a sol–gel route. A pre-coat of peroxotitanium complex was employed to improve adhesion and inhibit the substrate degradation. The coating reduced the transparency for 10–15%. The photocatalytic activity was found linearly dependent on the thickness. The reaction rate constant for methylene blue degradation was estimated 0.024 s − 1 for films of 150 nm thickness. The mechanical properties were also improved after coating, as demonstrated by nano-indentation and nano-scratch tests. The hardness and scratch resistance were improved by 2.5 and ∼6.4 folds.

Control of Mechanical Properties of Thermoplastic Polyurethane Elastomers by Restriction of Crystallization of Soft Segment

Abstract: Mechanical properties of thermoplastic polyurethane elastomers based on either polyether or polycarbonate (PC)-glycols, 4,4'-dipheylmethane diisocyanate (1,1'-methylenebis(4-isocyanatobenzene)), 1,4-butanediol, were controlled by restriction of crystallization of polymer glycols. For the polyether glycol based-polyurethane elastomers (PUEs), poly(oxytetramethylene) glycol (PTMG), and PTMG incorporating dimethyl groups (PTG-X) and methyl side groups (PTG-L) were employed as a polymer glycol. For the PC-glycol, the randomly copolymerized PC-glycols with hexamethylene (C₆) and tetramethylene (C₄) units between carbonate groups with various composition ratios (C₄/C₆ = 0/100, 50/50, 70/30 and 90/10) were employed. The degree of microphase separation and mechanical properties of both the PUEs were investigated using differential scanning calorimetry, dynamic viscoelastic property measurements and tensile testing. Mechanical properties could be controlled by changing the molar ratio of two different monomer components.

Tuning the Selectivity of the Oxetane and CO2 Coupling Process Catalyzed by (Salen)CrCl/n-Bu4NX: Cyclic Carbonate Formation vs Aliphatic Polycarbonate Production

Abstract: The (salen)CrIIICl complex 1, (1,2-cyclohexanediamino-N,N′-bis(3,5-ditert-butylsalicylidene)chromium(III) chloride), in the presence of n-Bu4NX (X = Br, I, Cl, N3, NCO) as cocatalyst has been shown to be an effective catalytic system for the coupling of oxetane and CO2 providing the corresponding aliphatic polycarbonate with small quantities of ether linkages at 110 °C. The selectivity of the oxetane and CO2 coupling process has been effectively tuned for the formation of polycarbonate produced directly from the homopolymerization of preformed trimethylene carbonate (TMC), in the presence of complex 1 along with n-Bu4NBr as cocatalyst, at temperatures lower than 80 °C. Notably, under these conditions the amount of carbonate linkages obtained was remarkably high (>99%). An investigation of the initial catalytic species involved in the coupling reaction was performed by ESI mass spectral analysis, revealing a Schlenk (ligand redistribution) equilibrium of the three possible anions formed after treatment of ...

Effect of processing parameters on morphology and thermal properties of electrospun polycarbonate nanofibers

Abstract: In the present contribution, it has been reported about the effect of solvent, solvent concentration, flow rate and applied voltage on the fabrication of electrospun polycarbonate (PC) nanofibers. The morphology of fibers was studied by optical and scanning electron microscope. It is observed that morphology of fibers depends upon the concentration of PC or viscosity of the solution, vapor pressure and diffusion coefficient of solvent. In fact, when viscosity of the solution is very low, beads or droplets are formed instead of fibers. The same problem arises when the viscosity of the solution is too high due to high surface tension. In this case, jet formation will not be observed and the solution will coagulate at the tip of needle. Tetrahydrofuran (THF) easily diffuses with polymer, at higher concentration of PC and at higher flow rate of solution; fibers of micron size are formed because of high vapor pressure of THF. On the other hand, in case of mixed solvents (DMF and THF), by controlling processing parameters one can get fiber diameter up to 200 nm. The study of Differential Scanning Calorimetry (DSC) indicates that less amount of heat energy is absorbed during endothermic reaction and there is a slight increase in glass transition temperature of nanofibers. Thermogravimetric analysis (TGA) shows an increase in thermal stability of PC nanofibers by 40oC as compared to PC granules. This is due to the alignment of PC polymeric chains during stretching and whipping that occurs while electro spinning process. Copyright © 2010 VBRI press.

Reinforced thermoplastic resin composition and molded article

Abstract: The reinforced thermoplastic resin composition of the present invention includes: 50 to 90% by weight of a polycarbonate resin (A); 10 to 50% by weight of a graft copolymer mixture (B) (provided that a total amount of the component (A) and the component (B) accounts for 100% by weight) which is obtained by graft-polymerizing an aromatic alkenyl compound monomer unit (a) and a vinyl cyanide compound monomer unit (b) onto a rubber polymer (B1); and 6 to 22 parts by weight of an inorganic filler (D) which has been surface-treated with a water-soluble polyamide, relative to the total of 100 parts by weight of the polycarbonate resin (A) and the graft copolymer mixture (B). There is provided a reinforced thermoplastic resin composition exhibiting excellent moldability, generates a minimal amount of gas during molding, and also being capable of improving the rigidity of the resulting molded article and the impact resistance when dropping the product.

Heterogeneous Cation Exchange Membrane: Preparation, Characterization and Comparison of Transport Properties of Mono and Bivalent Cations

Abstract: Polycarbonate heterogeneous cation exchange membranes were prepared by solution casting techniques using tetrahydrofuran as solvent and cation exchange resin powder as functional groups agent. The effect of resin ratio loading on properties of prepared membranes was studied. Also, transport properties of the prepared membranes for mono and bivalent cations were evaluated. Scanning electron microscopy and scanning optical microscopy were used for the membranes structure investigation. Images showed that increase of resin ratio in casting solution results in a highly uniform phase to form. Formation and propagation of voids, cavities, and cracks were facilitated through higher resin ratio loading. The water content, surface hydrophilicity, specific surface area, ion exchange capacity, ion concentration, ionic permeability, conductivity, flux, and current efficiency of the membranes were enhanced and their energy consumption, oxidative stability, and mechanical strength were declined by increase of resin rat...

Flame-retardant reinforced polycarbonate compositions

Abstract: A composition containing a polycarbonate, a polycarbonate-polysiloxane copolymer, an alicyclic hydrocarbon resin flow promoter, an inorganic filler, a flame retardant and an impact modifier The compositions may include polycarbonate in an amount of 40% by weight or more of the combined weights of the polycarbonate, polycarbonate-polysiloxane copolymer, inorganic filler, flame retardant, flow promoter, and impact modifier compound wherein a molded sample of the thermoplastic composition is capable of achieving UL94 V0 rating at a thickness of 12 mm (± 10%); wherein the polymer composition has a melt viscosity of 185 Pa•sec or less, when measured at 270°C and 1500 sec -1 ; and wherein a molded sample of the thermoplastic composition has a flexural modulus determined in accordance with ASTM D790 within 3800-8000 MPa; and wherein a 32-mm thick molded NII bar comprising the composition has a notched Izod impact strength of 40 to 200 J/m determined in accordance with ASTM D256 at 23°C

Surface modification of polycarbonate by plasma treatment

Abstract: The surfaces of polycarbonate films were treated by nitrogen plasma, in order to understand the effect of low energy ions on the surface modification of polycarbonate. The modified samples were characterized by micro-hardness tester, optical micrograph/atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and FTIR spectroscopy. It was observed that the hardness of the film increases as fluence increases. This may be attributed to the cross-linking effect as corroborated with FTIR spectra. XPS analysis indicates that chemical bonding on the surface of the film, especially C=O, C-O and C-C/C-H functional groups, was found to change due to plasma treatment. AFM analysis reveals that average surface roughness increases from 5.9 nm to 42.7 nm as fluence increases.

Scratch resistance of polycarbonate containing ZnO nanoparticles: effects of sliding direction.

Abstract: Abrasive wear resistance of injection molded polycarbonate (PC) and polycarbonate + zinc oxide nanocomposites containing 0.5 wt% ZnO nanoparticles was determined as a function of the sliding direction with respect to injection flow. First we have done single scratch testing under progressively increasing the load applied. Then sliding wear testing consisting of 15 successive scratches along the same groove was performed. Neat PC shows anisotropic behavior, with instantaneous penetration depth more than 50% higher in the direction parallel to the melt injection flow than in the transverse direction. Viscoelastic recovery after scratching of neat PC is also higher in the longitudinal than in the transverse direction, hence final residual depth values are similar in both directions. The addition of ZnO nanoparticles reduces the instantaneous penetration depth in the longitudinal direction but lowers viscoelastic recovery so that the residual depth is large. In the transverse direction, the scratch resistance is similar for neat PC and the nanocomposite. Dynamic mechanical analysis, SEM/FIB results and wear mechanisms from SEM observations of wear scars are discussed. Below the glass transition region the nanocomposite has distinctly higher storage modulus E’ than PC—a clear reinforcement effect. However, the addition of ZnO nanoparticles to the polymer increases the material brittleness at room temperature by a factor of 2.72.

Polycarbonate resin composition and molded article

Abstract: An object of the present invention is to provide a polycarbonate resin composition and a molded article, which are excellent in jet-blackness, image sharpness, impact resistance, scratch resistance owing to high hardness, flame retardancy and heat retention stability. The present invention provides a resin composition comprising a polycarbonate resin comprising a structural unit derived from a cyclic ether structure-containing dihydroxy compound and a coloring agent, which is a polycarbonate resin composition having an L* value of 6 or less as measured by the reflected light method of JIS K7105; and a molded article using the resin composition. The resin composition and the molded article of the present invention can be used over a wide range of fields allowing a product to be imparted with a high-grade appearance and a dignified impression.

Polycarbonate resin composition

Abstract: To provide a polycarbonate resin composition having a high Abbe's number, high strength and excellent stainability Disclosed is a polycarbonate resin composition prepared by blending a polycarbonate resin (A) prepared by forming carbonate bonds in tricyclo[5210 2,6 ]decanedimethanol with a diester or phosgene, and a weight-averaged molecular weight (Mw) of the polycarbonate resin (A) being equal to or more than 25,000, and a polycarbonate resin (B) prepared by reacting 2,2-bis(4-hydroxyphenyl)propane and phosgene, and weight-averaged molecular weight (Mw) of the polycarbonate resin (B) being equal to or more than 30,000, wherein a ratio thereof, 100×(A)/((A)+(B)), is from 1 to 99% by weight

Polycarbonate resin composition and molded product using the same

Abstract: Disclosed are a polycarbonate resin composition that includes (A) about 5 wt % to about 89 wt % of a polycarbonate resin; (B) about 10 wt % to about 94 wt % of a polycarbonate-polysiloxane copolymer; and (C) about 1 wt % to about 70 wt % of a modified acrylic-based copolymer, and a molded product made using the polycarbonate thermoplastic resin composition.

Easily adhesive thermoplastic resin film

Abstract: Disclosed is a highly adhesive thermoplastic resin film which is substantially free from decrease in adhesion under high temperature high humidity conditions. Specifically disclosed is a highly adhesive thermoplastic resin film which comprises a coating layer on at least one surface of a base film. The highly adhesive thermoplastic resin film is characterized in that the coating layer contains (a) a urethane resin that contains a polycarbonate polyol as a component, and/or a polyester resin that does not substantially contain a carboxylic acid group and has a number average molecular weight of not less than 15,000, and (b) a carbodiimide compound.

Polycarbonate composition and preparation method thereof

Abstract: The invention provides a polycarbonate composition and a preparation method thereof. The polycarbonate composition comprises 30-90% of polycarbonate, 5-50% of polyester, 1-10% of compatible toughening agents, 1-10% of low-temperature impact modifiers, 0.1-1% of anti-ultraviolet assistant, 0.1-2% of antioxidants and 0.1-1% of lubricant by mass. The preparation method comprises the following steps: weighing the components in the composition according to the mass proportion; throwing the polycarbonate, the polyester, the compatible toughening agents, the low-temperature impact modifiers, the anti-ultraviolet assistant, the antioxidants and the lubricant into a mixer to be uniformly mixed; and melting, mixing, extruding and pelleting the uniformly mixed raw materials by an eight-temperature zone double-screw extruder. The polycarbonate composition has high molding processing mobility and excellent chemical reagent resistance, anti-ultraviolet property and low-temperature anti-impact property and can be widely applied to thin-wall workpieces.

Flame-resistant polyester-polycarbonate compositions, methods of manufacture, and articles thereof

Abstract: A composition comprising a polyester, polycarbonate, organopolysiloxane- polycarbonate block copolymer, organophosphorus flame retardant, fluorinated polyolefin, and one or more additives. In one embodiment, the composition has an improved balance of properties, including one or more of a melt volume rate, Vicat softening temperature, notched Izod impact strength and a UL 94 flammability rating.

Polycarbonate-polyorganosiloxane copolymer, process for production of the copolymer, and polycarbonate resin containing the copolymer

Abstract: A polycarbonate-polyorganosiloxane copolymer (A-1) comprising a polycarbonate block composed of a specific constituent unit and a polyorganosiloxane block composed of a specific constituent unit, wherein the copolymer is characterized in that (1) the content of the polyorganosiloxane block moiety is 1 to 30 mass%, (2) the average repeating unit number of constituent units represented by general formula (II) is 70 to 1000, (3) the copolymer has a viscosity average molecular weight of 13000 to 26000, and (4) the content of a phenol residue having an allyl group in the copolymer is 400 ppm by mass or less, and wherein the copolymer enables the production of a molded article having excellent thermal stability and a good color even when the molding is carried out at a higher temperature; a process for producing the polycarbonate-polyorganosiloxane copolymer; and a polycarbonate resin produced using the polycarbonate-polyorganosiloxane copolymer.

Patterning of tailored polycarbonate based non-chemically amplified resists using extreme ultraviolet lithography

Abstract: A series of high-performance polycarbonates have been prepared with glass-transition temperatures and decomposition temperatures that are tunable by varying the repeat-unit chemical structure. Patterning of the polymers with extreme UV lithography has been achieved by taking advantage of direct photoinduced chain scission of the polymer chains, which results in a molecular-weight based solubility switch. After selective development of the irradiated regions of the polymers, feature sizes as small as 28.6 nm have been printed and the importance of resist-developer interactions for maximizing image quality has been demonstrated.

9,9′-spirobifluorene-containing polycarbonates: Transparent polymers with high refractive index and low birefringence

Abstract: Syntheses of 2,2′-bisalcoholic group-substituted 9,9′-spirobifluorene monomers 2 were performed by the reaction of 2,2′-dihydroxy-9,9′-spirobifluorene 2a with haloalcohols. Polycarbonates consisting of 9,9′-spirobifluorene skeleton in the main chain (PC 4) were synthesized by the polycondensation of 2,2′-bisalcoholic monomers 2 and triphosgene or diphenyl carbonate. PC 4 showed good thermal stability: the 5% weight loss temperature was over 330 °C under both nitrogen and air atmospheres. The glass transition temperature was in a range of 16–269 °C estimated by differential scanning calorimetry, depending on the flexibility of the alkylene or oxyethylene chains of 2. PC 4 showed high solubility toward ordinary organic solvents such as CHCl3, benzene, and THF, making possible the preparation of the flexible thin films. Very high refractive index in a range of 1.62–1.66 at 589 nm was observed although PC 4 consists only of C, H, and O atoms, whereas very low degree of birefringence was confirmed. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3658–3667, 2010