摘要:

An analysis is presented of the potentials of highly efficient applications of acrylamide (co)polymers in various branches of industry and agriculture, including oil and textile industries, as well as in the function of an active additive that reduces the viscosity of liquids under turbulent flow conditions, forms soil structure, etc. Detailed consideration is given to the effect of various parameters of acrylamide (co)polymers, such as the molecular weight, composition, distribution of molecular weight and composition, etc., upon the efficiency of the flocculation processes on model and real-life dispersed systems.

ISSN:0360-2559    

DOI:10.1080/03602559108020132

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Poly-p-vinyl styrene was prepared photochemically. It was found that the preparation and molecular weight of this new polymer depend on several factors such as concentration, source of irradiation, time of irradiation, and solvents used.

ISSN:0360-2559    

DOI:10.1080/03602559108020133

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Shear-thickening behavior of dilute polymer solutions reported in the literature was generally observed in capillary or cone-and-plate geometry. Experiments conducted on solutions of Pusher 700 in a Couette viscometer failed to detect such a phenomenon. The same polymer solutions have been reported to exhibit shear-thickening behavior in a cone-and-plate geometry. A simple flow instability analysis suggests a possible link between flow instability and shear-thickening behavior in a cone-and-plate geometry. In capillary flow, entrance and exit effects, and surface effects such as polymer adsorption and gel formation could also account for the observed shear-thickening phenomenon.

ISSN:0360-2559    

DOI:10.1080/03602559108020134

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

ISSN:0360-2559    

DOI:10.1080/03602559108020135

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

In this article a theoretical background for understanding dielectric phenomena in heterogeneous polymeric composites is presented, and the application of these principles to practical problems is illustrated by experimental examples. First a short overview of the existing theoretical mixing formulae is given, the differences in these approaches are discussed, and the areas of application are indicated. Conditions for the appearance of an interfacial relaxation process are delineated; limitations of the theories are given. Experimental examples include immiscible polymer blends, mineral-filled polyolefins, thermoset composites, and conductive composites. In the first example, AC dielectric spectroscopy is used to monitor the phase separation process and to evaluate interactions between the separated phases. In the second example, the effect of filler permittivity, volume fraction, and surface treatment is discussed with respect to the AC and DC dielectric properties. It is shown that in mineral-filled polyolefins, water adsorbed at the matrix-filler interface plays an important role. In the third example, the effect of filler purity (and conductivity) on the dielectric properties is demonstrated. Nonelectrical-grade glass powder causes a strong interfacial polarization and electrode polarization in an unsaturated polyester resin, whereas electrical-grade glass fiber reinforcement leads to minor property changes. In the final example, the effects of processing conditions on the AC conductivity and permittivity of conductive composites is discussed. Extensive shear and orientation cause a shift of the percolation threshold, thus reducing the conductivity. Thus it is shown that dielectric methods can be used to investigate problems in processing technology.

ISSN:0360-2559    

DOI:10.1080/03602559108020136

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Polyurethane reaction between a new polyol and TDI under isothermal conditions was investigated. The progress of the reaction was monitored by following the viscosity as well as the monomer conversion. Viscosity variations were measured by means of a cone-and-plate viscometer while conversion was estimated by IR technique. An already reported empirical relationship between these two was verified. Stockmayer's formula for weight average molecular weight of a linearly polycondensing system was used to find molecular weights at every stage of the reaction. The interdependence of viscosity and weight average molecular weight was confirmed, and the value of the indexmwas obtained.

ISSN:0360-2559    

DOI:10.1080/03602559108020137

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Stabilizer and plasticizer systems were studied for a PVC waterproofing sheet formulation to be processed by calendering. Combinations of stabilizer-lubricant systems that contained (Ba, Cd, Zn), dibasic lead phosphite, epoxidized soybean oil, barium stearate, calcium stearate, and stearic acid were evaluated. Oven aging tests showed that the system that contained 2 phr (Ba, Cd, Zn) stabilizer, 0.5 phr barium stearate, 5 phr epoxidized soybean oil, and 0.25 phr stearic acid was satisfactory. Combinations of diisodecylphthalate (DIIP), tricresyl phosphate (TCP), polybutylene adipate (PBA), and NBR were evaluated as the plasticizer system. Tensile properties in the machine and the transverse directions, cold flex temperature, loss of volatile matter content, and aging properties were studied as functions of the DIIP and PBA contents. A plasticizer system of 35 phr DIIP and 18 phr PBA was found to be satisfactory. The final formulation was processed at industrial scale and the product was characterized for its tensile properties, cold flex temperature, tear resistance, weldability, permeability to water, shrinkage, and its resistance to heat, light, acid, and water.

ISSN:0360-2559    

DOI:10.1080/03602559108020138

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The peculiarities of the macrokinetics of rapid polymerization processes in turbulent flows (when the times of the chemical reaction are less than or compatible with those of the reagent mixing) have been discussed. The characteristic specific phenomena have been elucidated, namely: dependence of the molecular characteristics output (MW and MWD) of the polymer formed on the geometry of the reaction volume and on the parameters of the processes of mixing and heat transfer (flow rates, turbulization, boiling, etc.). Such reactions require special methods of investigation and control including those in industries with principally new material-, resource-, and power-saving technology, in particular, for the production of the isobutylene polymers. It is expedient to distinguish the rapid processes of polymerization as a separate class.

ISSN:0360-2559    

DOI:10.1080/03602559108020139

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0360-2559    

DOI:10.1080/03602559108020131

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor