摘要:

New aromatic polyamides from the bisamines 2,2-bis(p-amine-pheny1)-1, 1,1-trichloroethane (Bisamine I), 2,2-bis(p-amine-pheny1)-1,1-dichloroethylene (Bisamine II), and terephtaloil chloride were synthesized by means of several methods. It was found that low-temperature solvent polycondensation is optimum for obtaining polymers with the best properties, which are predominantly better in the case of polyamides based on Bisamine II.

ISSN:0022-233X    

DOI:10.1080/00222338108063226

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Investigations on a new class of polyamides obtained by interfacial polycondensation from amine-chloral derivatives, e.g., 2,2-bis(p-aminophenyl)-1,1,1-trichloromethane or 2,2-bis(p-aminophenyl)-1, 1-dichloroethylene and terephthaloyl chloride, have been carried out. It was found that the interfacial process proceeds in the most advantageous way in acidic medium at 0°C using equivalent volume amounts and equimolar concentrations of methylene chloride and water phases in the presence of a stoichiometric quantity of triethylamine as the hydrogen acceptor.

ISSN:0022-233X    

DOI:10.1080/00222338108063227

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Reaction behaviors of carbon disulfide and carbon dioxide in plasma were investigated and compared. It was found that carbon disulfide is very reactive in plasma to produce dark brown filmy polymers, but carbon dioxide does not give polymeric products at all. The difference in plasma behaviors of the two monomers can be attributed to the roles of sulfur and oxygen in the monomers. There is also some discussion on the spectro-scopic data of carbon disulfide polymers.

ISSN:0022-233X    

DOI:10.1080/00222338108063228

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The kinetics of the exchange of chloride ions in an anion-exchange resin has been studied. The rate measurements were carried out by a potentiometric technique, and thus both the kinetic and the activation parameters of the reaction were determined. The results concerning the influence of the stirring velocity upon the fractional attainment of equilibrium prove that the diffusion of the C1‒ species into the resin beads plays an important role in the mechanism of the exchange reaction, although the exchange rate is chemical in its ultimate mechanism.

ISSN:0022-233X    

DOI:10.1080/00222338108063229

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Nylon 6 filaments were drawn under high pressure. By means of wide-angle x-ray diffraction and differential scanning calorimetry, nylon 6 fibers were investigated after drawing at 80° C to a draw ratio of 3.75 and pressure in the range of atmospheric up to 2000 kg/cm2It was found that by increasing the pressure, structural conversion from the γ-pseudohexagonal to the α-monoclinic form occurs, and that crystallinity and orientation are also increased.

ISSN:0022-233X    

DOI:10.1080/00222338108063230

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

A tannin-based adhesive formulation for particleboard based on the simultaneous reactions of small amounts of diisocyanates and formaldehyde with tannin extracts of the flavonoid type and useful to prepare good exterior grade particleboard is presented and discussed. The adhesive performs well when using any kind of flavonoid-type tannin extract.

ISSN:0022-233X    

DOI:10.1080/00222338108063231

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The polymerization of vinyl monomer initiated with poly-2-hydroxyethylmethacrylate (PHEMA) in water was carried out at 85°C. Cu(II) ion was not necessary for this polymerization. Methacrylate monomers were polymerized, while styrene and acrylonitrile were not. The polymerization was found to proceed through a radical mechanism in the interior of PHEMA which was swelled in water. The grafting efficiency of MMA polymer obtained was about 90%. The overall activation energy was estimated to be 32.9 kJ/mol.

ISSN:0022-233X    

DOI:10.1080/00222338108063232

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The polarographic behavior of the redox polymer poly-p-xylylviologen dibromide has been examined over the pH range 2.00–8.00. Two irreversible waves with half-wave potentials of −0.496 and −0.936 V vs SCE were observed. The pH dependence of the relative wave heights appears to suggest that the system conforms to a protonation equilibrium where the protonated form reduces, at the DME, at the lower negative potential and the second wave is due to the unprotonated species. Analysis of the limiting current-pH relationship for a given concentration of the compound yielded a value of 7.94 × 10−−5(μ=0.1 M) for the dissociation constant of the protonated form.

ISSN:0022-233X    

DOI:10.1080/00222338108063233

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The free radical copolymerization of styrene and other vinyl monomers to produce cross-linked, network polymers is of technological importance in the production of ion-exchange resins, packings for gas-liquid and gel permeation chromatography, cross-linked latex polymers, and other products. The principal multifunctional cross-linking monomers which are used in this connection are ethylene glycol dimethacrylate and divinylbenzenes, and accurate values for reactivity ratios in their reactions with bifunctional monomers are essential for the design of copolymerization processes and products.

ISSN:0022-233X    

DOI:10.1080/00222338108063234

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

A method for planning of experiments has been elaborated which makes it possible to decide the adequacy of the two-parameter model of binary copolymerization. At the same time, the procedure provides equal and reasonably low relative errors of r1and r2. In the approximate knowledge of the parameters and of the value of analytical error, the procedure furnishes the number of measurements and the monomer feed values necessary for the desired accuracy. It was obtained as a “rule of thumb” that, in spite of the erroneous practice, the points should be arranged uniformly within the range of copolymer composition instead of monomer composition. For the objective performance of retrospective evaluations, an “efficiency factor” has been introduced.

ISSN:0022-233X    

DOI:10.1080/00222338108063235

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor