摘要:

AbstractThree types of functional microgels with vinyl groups on their surface were prepared. For the first type, the counter anion from clorin was exchanged with β‐methacryloylethyl sulfonic acid, styrene sulfonic acid or allyl sulfonic acid in a microgel with ammonium anions. For the second and third types, a quaternization with N,N‐dimethylaminoethyl methacrylate of 3‐chloro‐2‐hydroxypropyl methacrylate in the presence of microgel particles was prepared by emulsion copolymerization of styrene, chloromethylstyrene or N,N‐dimethylamino‐methylbenzene, and divinylbenzene. The resulting samples show good dispersibility in organic solvents without an emulsifier.A functional microgel‐based photopolymer combined with an acrylate monomer and ultraviolet (UV) or visible (VIS) light‐absorbing photoinitiators provides oleophilic images when exposed to UV or VIS light and developed in tap water. This photopolymer has a higher sensitivity than those of photopolymers based on microgels with an analogous composition but without vinyl groups. Photopolymers pepared by using functional microgels with a methacryloyl group exhibited a higher rate of polymerization (Rp) than that of photopolymers based on microgels without a vinyl group. The Rpof photopolymers prepared by using a functional microgel with either an allyl group or vinylphenyl group was nearly equal to that of photopolymers based on microgels with ammonium ions. Their high sensitivities are attributed to the rapid photopolymerization in the methacryloyl group.To determine how the photoreaction mechanism enhances sensitivity, the photoreaction products were investigated using a model photopolymerization system. It was found that the gelation reactions enhancing sensitivity are predominantly the polymerization and crosslinking ones when a microgel with the methacryloyl group is used, and the graft copolymerization with acrylate monomers when a microgel with either the allyl group or vinylph

ISSN:1042-7147    

DOI:10.1002/pat.1994.220050601

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractPoly(p‐phenylene sulfide sulfonic acid) was thermally crosslinked for use as a cation exchange polymer with high thermal stability. The decomposition temperature (Td) of the polymer increases with an increase in the crosslinking temperature. The crosslinking reaction at 300°C in air resulted in the formation of a strongly acidic cation exchange polymer with a T d 10%= 467°C and having an SO2bond, whose crosslinked structure was investigated using IR spect

ISSN:1042-7147    

DOI:10.1002/pat.1994.220050602

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractDense membranes were prepared from poly(vinyl alcohol)–poly(N‐vinyl pyrrolidone) (PVA–PVP) blends of different compositions and studied in swelling and dehydration by pervaporation of three organic solvents contaminated by 5 wt% water. The swelling generally increases with the PVP content. No extraction occurs in water–tetrahydrofuran (THF) and water–methyl ethyl ketone (MEK) mixtures. In ethanol containing 10 wt% of water, there is no extraction for blends containing less than 40 wt% PVP and an increasing extraction beyond this PVP content. The pervaporation flux of the water–ethanol mixture increases drastically at the same threshold whereas the water permselectivity falls to a low level. The values of the diffusion and permeability coefficients determined from transient permeation of the test water–ethanol mixture exhibit a similar sudden increase at the same PVP content threshold. This singular behavior of the blend membranes is interpreted by a strong affinity of the PVP component to ethanol, combined with a disappearance of crystallites in the blend at this threshold. Consequently the amorphous membrane can swell freely according to the affinity of the PVP component, leading to the obse

ISSN:1042-7147    

DOI:10.1002/pat.1994.220050603

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractDense membranes made by crosslinking of poly(vinyl alcohol) (PVA) with poly(acrylic acid) (PAA) were prepared and tested in pervaporation and differential permeation of water–alcohol mixtures. Instead of a decrease of permeation flux as generally observed with most crosslinking agents, an increase in the permeability was observed with PAA crosslinked membranes at low PAA contents. The permeation flux increases with PAA contents in the polymer with no selectivity reduction for membranes containing less than 15 wt. % PAA. The membranes show good performances to water–2‐propanol and water–ethanol mixtures, i.e. high fluxes and high selectivities to pure water. The membranes were stable and highly permeable to water. The enhancement of the permeability of PVA can be explained by a reduced crystallinity and an improved diffusivity due to the presence

ISSN:1042-7147    

DOI:10.1002/pat.1994.220050604

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractBlends of ABS (acrylonitrile–butadiene–styrene) with phenoxy(poly(hydroxyether bisphenol A)) were prepared using a Branender single screw extruder. Scanning and transmission electron micrographs (SEM, TEM) showed a typical two‐phase morphology; particle‐in‐matrix (90/10) (ABS/phenoxy by weight), 70/30, 10/90), island/sea (30/70) and co‐continuous (50/50) morphologies. The glass transition temperature (Tg) of SAN was almost unchanged in the blends, while the Tgof phenoxy increased by about 5 °C in the blends. The synergistic effect of tensile modulus and strength was noted in ABS‐rich blends, where a drastic drop of ductility was seen, and the results were interpreted in terms of rubber particle migration form SAN to phenoxy phase, which was visualized by TEM. Melt viscosity showed yield in ABS‐rich blends, and generally followed th

ISSN:1042-7147    

DOI:10.1002/pat.1994.220050605

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractIn this paper we focus on miscible blends of two engineering polymers: poly(butylene terephthalate) (PBT) and a polyarylate (PAr). The issue of transesterification in these blends will be addressed, followed by a discussion of the crystallization kinetics of PBT, poly(ethylene terephthalate) and several PBT/PAr blends. The ability to estimate polymer–polymer interaction parameters in blends from melting point depression will also be discussed. The amorphous phase behavior of the PBT/PAr blends has been explored primarily using dielectric spectroscopy. For blends in which PBT has crystallized, we observe two relaxations associated with Tg‐like motion, and this behavior is interpreted in light of our recent work on order–disorder interphases in crystalline b

ISSN:1042-7147    

DOI:10.1002/pat.1994.220050606

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractPolymer modifications of ultrafine monodispersed colloidal metal oxide particles, smaller than 80 nm in diameter, by the graft‐polymerization of styrene to a hydrophilic macromer adsorbed on the surface were investigated. The polymerization in ethanolic silica and titania colloid solution, which had negatively larger ζ‐potentials, −30 and −42 mV in neutral aqueous solution respectively, gave poly(styrene)–silica or titania composite, being of nonspherical shape. The modifications of colloidal particles, having lower surface energy, such as Al(OH)3and CeO2–TiO2–SiO2complex, led to the formation of spherical composites, ranging in size from 500 to 3000 nm, of scattered metal oxide or hydro

ISSN:1042-7147    

DOI:10.1002/pat.1994.220050607

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractChemical synthesis of polypyrrole (PPy) was carried out in the presence of FeCl3aqueous solution. The grown PPy is fixed on the sulfonated surface of polyethylene (SPE) films, where the sulfonic groups act as counteranions to balance the positive charge of PPy, giving the composite material of PPy–SPE.For reasons of comparison, two types of polyethylene (PE) have been used, low and high densities with different degrees of sulfonation, SD (g/m2), defined as the ratio of weight increase to the area of the two surfaces of the sample. A series of reaction times was used to evaluate the variation of the electrical conductivity, σ (S/cm), of polypyrrole. It was found that σ increases as reaction time increases.To characterize the samples, Fourier transform infrared (FTIR) spectroscopy and conductivity measurements were perfor

ISSN:1042-7147    

DOI:10.1002/pat.1994.220050608

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY