Homo- i kopolimeryzacja styrenu, inicjowana nadsiarczanem potasu bez użycia emulgatora, przebiegająca w warunkach statycznych. Cz. I. Homopolimeryzacja styrenu

• Autorzy: Wilson-Polit, D. , Orzechowski, A. , Grzywa-Niksińska, I. , Grzywa, E. , Izmailova, V. , Oganesyan, A. , Gritskova, I.

Warianty tytułu

EN

Static-condition no-emulsifier potassium persulfate-initiated homo and copolymerizations of styrene. Part I. Homopolimerization of styrene

• Języki publikacji: PL

Abstrakty

EN

A mechanism in suggested for homopolymerization of styrene, which is based on interfacial tension (σ1,2), ζ-potential, and product particle size distribution measurements. The homopolymerization was carried out in the water phase at 60oC or 80oC under static conditions (no stirring) with no emulsifier used; it was initiated with K2S2O8. At the first stage, initiation of polymerization in the water phase yields surface active oligomeric radicals part of which, soluble in monomer, are transferred from the water to the monomer phase, according with their solubility. Polymerization continues at the interfacial layer. As a result of this transformation and initiation of polymerization the s1,2 tension becomes very low and the monomer gets crushed. Polymer—monomer particles are formed from the monomer drops. In the process of obtaining polymers in the polymer—monomer particles, the density of which is lower than that of monomer and the particles are detached from the interfacial boundary and are passing into the water phase which becomes turbid. At the initial stage of polymerization, the polymer—monomer particles formed from monomer microdrops vary in size (Figs. 7, 8) because the stability factors (ζ-potential-controlled electrostatic factor and structural-mechanical factors) are forming in time at the interfacial adsorption layer of polymer—monomer particles. This mechanism is inconsistent with the Fitch et al. theory of homogeneous nucleation of particles. Presumably the low σ1,2-value conditioned by processes occurring at the interfacial boundary in the systems investigated is the reason for particulation of the monomer phase and formation of microdrops which are the major source for the formation of polymer—monomer particles.

Słowa kluczowe

PL

polimeryzacja styrenu; warstwa międzyfazowa; czynniki stabilności suspensji; napięcie międzyfazowe

EN

polymerization of styrene; interfacial layer; suspension stabilizing factors; interfacial tension

• Czasopismo: Polimery
• Rocznik: 2000
• Tom: T. 45, nr 5
• Strony: 399-404

Twórcy

autor

Wilson-Polit, D.

autor

Orzechowski, A.

autor

Grzywa-Niksińska, I.

autor

Grzywa, E.

autor

Izmailova, V.

autor

Oganesyan, A.

autor

Gritskova, I.