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Reactions of polyisoprene, polybutadiene and polyoctenamer in o-xylene with dibenzoyl peroxide and dicumyl peroxide were investigated by measuring the apparent viscosity qa of the solutions with a coaxial cylinder viscometer. As a new effect a "pre-maximum" in the increase of qa with reaction time was found. Possible reasons for the pre-maximum being due to the measuring device could be excluded. The dependence of the pre-maximum on the reaction conditions was investigated. A probable explanation of the pre-maximum is that the network first formed is destroyed by shear. ZUS AMMENFASSUNG:Die Umsetzungen von Polyisopren, Polybutadien und Polyoctenamer in 0-Xylol mit Dibenzoylperoxid und Dicumylperoxid wurden durch Messung der scheinbaren ViskositBt qa der Ltisungen mit einem Koaxialzylinder-Viskosimeter untersucht. A l s ein neuer Effekt wurde ein "Vormaximum" in der Zunahme von qa mit der Reaktionszeit gefunden. Mtigliche Ursachen fur das Vormaximum, die auf die MeRvorrichtung zuriickzufuhren wken, konnten ausgeschlossen werden. Die Abhiingigkeit des Vormaximums von den Reaktionsbedingungen wurde untersucht. Eine wahrscheinliche Erklarung fiir das Vormaximum ist, dal3 das zunachst gebildete Netzwerk durch die Scherung zersttirt wird.' H.
Reactions of polyisoprene, polybutadiene and polyoctenamer in o-xylene with dibenzoyl peroxide and dicumyl peroxide were investigated by measuring the apparent viscosity qa of the solutions with a coaxial cylinder viscometer. As a new effect a "pre-maximum" in the increase of qa with reaction time was found. Possible reasons for the pre-maximum being due to the measuring device could be excluded. The dependence of the pre-maximum on the reaction conditions was investigated. A probable explanation of the pre-maximum is that the network first formed is destroyed by shear. ZUS AMMENFASSUNG:Die Umsetzungen von Polyisopren, Polybutadien und Polyoctenamer in 0-Xylol mit Dibenzoylperoxid und Dicumylperoxid wurden durch Messung der scheinbaren ViskositBt qa der Ltisungen mit einem Koaxialzylinder-Viskosimeter untersucht. A l s ein neuer Effekt wurde ein "Vormaximum" in der Zunahme von qa mit der Reaktionszeit gefunden. Mtigliche Ursachen fur das Vormaximum, die auf die MeRvorrichtung zuriickzufuhren wken, konnten ausgeschlossen werden. Die Abhiingigkeit des Vormaximums von den Reaktionsbedingungen wurde untersucht. Eine wahrscheinliche Erklarung fiir das Vormaximum ist, dal3 das zunachst gebildete Netzwerk durch die Scherung zersttirt wird.' H.
SynopsisPoly(methy1 methacrylate-g-urethane) was prepared by coupling between poly(methy1 rnethacrylate-co-2-hydroxyethyl methacrylate) and polyurethane. The polyurethane was obtained by bulk polycondensation of tolylene diisocyanate and polypropylene glycol. The two polymeric species were synthesized and characterized separately, and the composition of the grafted products varied only by the spacing of the grafted segments. Grafted copolymers with 5, 10, 20, 25, 40, 50, 70, and 90% of incorporated polyurethane have been prepared.
The technological and operational properties of polyester resins, unmodified and modified with new freely disperse fillers, were investigated. It was found that modification causes greater dependence of the viscosity on the fatigue load and acceleration of the curing reaction and an increase in the exothermic effect by 2.5-4.5 times. In addition, the strength properties of the modified composites and the water and chemical resistance and impact strength are increased. These finely disperse modifiers are of different colors so that they can act as pigments in concrete structures. Colored facing tiles fabricated from the tmlyester binders have both strength and distinctive decorative and protective properties.Unsaturated polyester resins (usually solutions of unsaturated polyesters in monomers: styrene, dimethacrylates, etc.) are the most common binders in composite materials for different applications (from buttons to yacht and aircraft parts). Their advantage over other binders which can be transformed into cross-linked polymers in polymerization or polycondensation reactions is due to such properties as low viscosity, rapid curing at room and even negative [1] temperatures, good compatibility with mineral fdlers and reinforcing fiber materials, and relatively low cost.Polyester composites containing finely disperse and granular (from sand to fine gravel) fillers and pigments are now widely used. In construction engineering, they are known as po!ymer concretes. Since these materials simulate natural decorative stone (marble, granite, jasper, onyx, malachite) in color, markings, and texture, they are used as decorative-trim tiles, in small architectural structures, sanitary engineering, in fabrication of monuments, etc.Fillers in polyester composites give them thixotropy of the properties (mastic, spackle, adhesive), decrease shrinkage and the exothermic effect in curing, decrease the thermal expansion coefficient, increase the hardness, strength, and heat resistance of the cured material, ensure a given color and markings, and decrease consumption of polymer.There are many types of mineral fillers, but local mineral raw material and industrial wastes are of the greatest technical and economic interest. A special feature of unsaturated polyester resim is their chemisorption interaction with Ca, Mg, Fe, and other oxides [2], which are the basic component in most sedimentary rocks and industrial wastes.We investigated the modifying effect of new finely disperse fillers (both natural and industrial) on the properties of polyester resins and developed composites for construction applications based on them. The fillers were selected for their mineralogical composition and low dispersion, which suggests high surface activity.Natural mineral raw material from the Shatrashansk Deposit in the Republic of Tatarstan was used: glauconite containing more than 30% iron oxide, less than 10% K20, less than 4% MgO, and zeolite-containing rock (ZCR) containing 20-24% zeolites, 20% silica, 51% clay components, and calcites (remainde...
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