摘要:

AbstractThe possibility of hydrostatic extrusion of solid polymer under back pressure has been studied. Operation of equipment is described that permits hydrostatic extrusion under back pressure at elevated temperatures. To understand how the pressure influences hydrostatic extrusion, extrusions of polyethylene under back pressure up to 392 MPa were conducted at temperatures below the melting point of polyethylene at atmospheric pressure (Tm1). Furthermore, hydrostatic extrusion in the solid phase could be conducted at temperatures beyondTm1, since the melting point of polyethylene increased markedly with increasing back pressure.

ISSN:0021-8995    

DOI:10.1002/app.1979.070230901

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractRadiation‐initiated polymerization of vinyl phosphonate oligomer (molecular weight 500–1000) and N‐methylolacrylamide from aqueous solutions was investigated with cotton printcloth, flanelette, and sateen fabrics and with cotton (50%)–polyester (50%) flannelette fabrics. Determinations were made of the effects of radiation dosage, mole ratio of vinyl phosphonate in the oligomer to N‐methylolacrylamide in aqueous solution, concentration of reactants, wet pickup of solutions on fabrics, and irradiation of both dry and wet fabrics on efficiency of conversion of oligomer and monomer in solution to polymer add‐on. The effects of vinyl phosphonate oligomer and N‐methylolacrylamide radiation‐initiated polymerization on some of the textile properties of cotton printcloth and on flame resistances of cotton and cotton–polyester fabrics were evaluated. The breaking strength of modified cotton printcloth was about the same as that of unmodified fabric; however, the tearing strength and flex abrasion resistance of modified fabric were reduced. The textile hand of the modified printcloth fabrics that had flame resistance indicated: interaction between cellulose and vinyl phosphonate oligomer–poly(N‐methylolacrylamide) and uniform deposition in the fibrous cross section (transmission electron microscopy); surface areas of heavy deposits of oligomer–polymer (scanning electron microscopy); and phosphorus located throughout the fibrous cross section (energy dispersive x‐ray analysis). Polymerization of vinyl phosphonate oligomer and N‐methylolacrylamide was radiation initiated with cotton–polyester fabric; however, this modified fabric did not ha

ISSN:0021-8995    

DOI:10.1002/app.1979.070230902

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractDiethylenetriamine was reacted with urea to form a noncyclic analog of ethyleneurea (one of the lowest members of a series of linear polyethyleneureas) which was characterized spectroscopically. Its reaction with formaldehyde to yield the N‐methylol derivative (N‐methylolpolyethyleneurea, degree of polymerization 2; NMP‐2) was investigated. The polymerization characteristics of the NMP‐2 were studied and compared with those of N‐methylol derivatives of cyclic ethyleneurea (related structurally) and melamine (related polyfunctionally). The NMP‐2 was applied to cotton fabrics by a pad–dry–cure process with Al2(OH)5Cl·2H2O as the polymerization crosslinking catalyst. Fabrics treated with the experimental reagent developed high levels of resilience (durable press appearance) and were characterized by significantly higher than conventional levels of retained strength and abrasion resistance. Analyses by electron microscopy of fibers treated with NMP‐2 and with the predominant conventional reagent, dimethyloldihydroxyethyleneurea, are reported. Attractive performance properties are discussed and attributed, at least in part, to rapid polymerization accompanying, or in advance of, etherification of cellulos

ISSN:0021-8995    

DOI:10.1002/app.1979.070230903

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractThe study of the adsorption of an organosiloxane onto a fumed silica was undertaken in order to improve our knowledge of the reinforcement of silicon rubbers by silica. IR and gas‐phase chromatography techniques were used to characterize the adsorption of octamethyltetracyclosiloxane. At room temperature, the occurrence of hydrogen bonding between the solute and the adsorbent was shown. The amount of material adsorbed according to this mechanism was shown to be strongly dependent on temperature. The heats of adsorption at various covering ratios were calculated from the isotherms measured at temperatures close to 150

ISSN:0021-8995    

DOI:10.1002/app.1979.070230904

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractThe polymerization of ethylene in an atmospheric pressure‐pulsed discharge has been studied. Partial pressures of ethylene up to 4 kN/m2were used with helium as a diluent. Deposition rates (on glass slides) were the same throughout the discharge volume over a wide range of operating conditions. These rates were in the 1–2 Å/sec range. The films were clear, soft, and showed good adhesion to the glass substrates. Oligomers large enough to visibly scatter 637.8‐nm light were observed in the gas phase under all conditions in which film deposition occurred. The experimental results suggest that Brownian diffusion of these oligomers was the rate‐limiting step in the film deposition

ISSN:0021-8995    

DOI:10.1002/app.1979.070230905

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractSystems of divalent metal salts of mono(ydroxyethyl)phthalate‐anhydride‐bisepoxide were evaluated as adhesives. The bisepoxides, bisphenol A diglycidyl ether (BADG) and hexahydrophthalic acid diglycidyl ester and the anhydrides, maleic anhydride and hexahydrophthalic anhydride (HPA) were used. The adhesive properties of the above metal‐containing systems were generally superior to those of the systems not containing metal, due to the polarity effect of metal carboxylate groups. The effect of introducing metal (ionic links) on tensile shear and peel strenghths clearly appeared, especially in the metal salt‐HPA‐BAD

ISSN:0021-8995    

DOI:10.1002/app.1979.070230906

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractInterpolymer ion exchange membranes were prepared from a compatible casting solution that contained poly(styrene sodium sulfonate), poly(vinyl methyl ether–alt–maleic anhydride), and poly(vinyl alcohol). Crosslinking of the films was accomplished through the formation of ester linkages that were stable in aqueous environments. Membrane properties (water content, capacity, concentration potential, equivalent conductivity) were measured over a wide range of membrane compositions. Ultrafiltration was carried out with a feed solution that was 0.01Nin KCI and 15 ppm in erythrosin. Rejection and hydraulic permeability data were reported as a function of membrane composit

ISSN:0021-8995    

DOI:10.1002/app.1979.070230907

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractThe plasma polymerization of C2F4was carried out in both continuous wave and pulsed rf discharges to establish the effects of reaction conditions on the kinetics of polymer deposition and the polymer structure. ESCA spectra of the polymer show evidence for CF3, CF2, and CH2 groups. Under conditions favoring low deposition rates, the dominant functional group is CF2. At higher deposition rates the concentration of CF2 groups is reduced and a more crosslinked polymer is produced. Both polymer deposition rates and polymer structures were essentially identical when using continuous wave and pulse

ISSN:0021-8995    

DOI:10.1002/app.1979.070230908

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractFlame retardant formulations for polypropylene are described that comprise a heat‐stable phosphonium bromide or phosphine oxide, containing cyanoethyl substituents, in combination with ammonium polyphosphate. At additive levels of (20–30)%, flame‐retarded polypropylene, with an Underwriters' Laboratories UL 94 V‐0 rating is obtained with little effect on thermal and mechanical properties of the polymer. A characteristic property of this flame retardant mixture is low smoke generation during burning. Mechanism studies indicate that the organophosphorus component alone acts as an inhibitor in the gas phase, whereas the ammonium polyphosphate alone acts in the condensed phase. The synergistic effect observed by the combination of these two components is due to the formation of a phosphorus‐rich char which forms an insulat

ISSN:0021-8995    

DOI:10.1002/app.1979.070230909

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractA series of metal and acid salts having poly(alkylbenzimidazoles) as the parent ligand were synthesized. The room‐temperature electrical resistivity of the parent and the salts was measured. Values for the dc electrical resistivity varied from ∼1 × 1013ohm.cm for the neutral polymers to ∼1 × 106ohm·cm for the acid conjugate formed by reaction with HCl. Unexpectedly, changes in resistivity did not correlate with acid strength as measured by us but could be roughly correlated with the molar volume of the corresponding acid or metal salt. The nature of the complexes was elucidated using the ESCA technique. The electron core levels of nitrogen, chlorine, and the various metals were examined. The observed photoelectron spectra indicated the formation of polybenzimidazole/acid and polybenzimidazole/metal salts. In addition, one was able to conclude that the complexes of Co and Ni were high spin, thus ruling out a planar geometry for the Ni(II)

ISSN:0021-8995    

DOI:10.1002/app.1979.070230910

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY