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Organosilicon foam stabilizers have been obtained by the grafting of polyether molecules on to polydimethylsiloxane. The way in which the molecular weight distribution and the number distribution of the polyether blocks in these compounds depend on the MWD of the organosilicon oligomer and the distribution of reactive hydrogen atoms along the oligomer chain has been determined.

Methodical features of using thin-layer chromatography for the study of molecular characteristics of oligoarylates are described. A calibration curve is plotted.

Studies were made of MW and MWD of thermo-plastic polyurethanes (TPU) by gel permeation chromatography (GPC) using styro-gels in ethyl acetate. It was shown that the polydispersion of TPU is close to two, independent of the method of synthesis (in bulk or in solution) and the numerical average MW increases from 44,000 to 162,000 with a change of intrinsic viscosity from 0·36 to 1·04.

Thin-layer chromatography (TLC) on silica gel is used in a preparative form to separate polyoxypropylene polyols according to functionality. The methods developed enable components to be separated in polyoxypropylene polyols with one, two and three hydroxyl groups in the molecule and these to be isolated quantitatively. A study was made of the effect on separating properties of factors such as silica gel particle size, thickness of the adsorbent layer and amount of substance used for separation. The accuracy of separation by preparative TLC was confirmed by results of investigation of the same samples by liquid column chromatography. Using gel-permeation chromatography to determine MW and MWD of the components separated a study was made of composition according to the functionality of a number of polyoxypropylene polyols.

A description is given of the use of thin-layer chromatography on silica gel for determining monofunctional impurities in hydroxyl-containing oligoesters. Optimum conditions were selected to determine monofunctional impurities with an accuracy of 25–30% of the amount determined, with a content of 1 to 5% in the oligoester. It was shown that in chromatographic analysis in a toluene-ethanol system on silica gel, adsorption takes place on hydroxyl end groups. The length of the glycol chain which determines the concentration of ester bonds has practically no effect on chromatographic properties of oligoesters.

The results of the fractionation and the mol.wt. of polyoxypropylene polyols (POPP) produced by the polyaddition reaction of propylene oxide with potassium glycerate in glycerol have shown that the neutral polyether contains two diol types one of which is the product of water and propylene oxide, the other from hydrolysis of the cis -propylene groups in the mono-ol. The amount of the second diol type produced is equivalent to the cis -propylene groups content of the alkaline poly-ether. The OH-groups content of the neutral poly-ether equals the sum of the OH-groups present in the glycerol, water, allyl alcohol and from the cis -propenyl groups present in the alkaline polymer. This has qualitatively confirmed the mechanism of the chain transfer on the monomer during the anionic polymerization of the propylene oxide and has shown this reaction to be the only source of new OH-groups production during the polymerization.

Hydroxyl-containing polyesters used for the synthesis of polyurethane thermoplastics have been fractionated according to functionality using the column liquid adsorption chromatography method. Gel permeation chromatography and thin-layer silicagel chromatography were used to analyze the fractions. The influence of titanium tetrabutylate on the functionality types distribution and MWD of the polyesters has been investigated. It was found that titanium tetrabutylate does not lead to branching along the chain, and has no significant influence on the functionality composition of the polyesters. The content of “defective” molecules in linear polyesters with M = 2000 depends on the nature and may be as high as 5%.

The possibility of fractionation based on M of phenol formaldehyde resins by GPC has been studied on the Sephadex of different grades and Styrogel. On fractionation in ethyl alcohol for the Sephadex separation occurs by the adsorption mechanism and in DMFA on both types of packings by the GPC principle.

A description is given of the thin layer chromatography of polyols using 6 × 6 cm plates coated with KSK silica gel, the chromatograms being developed with a Dragendorf reagent based on solvents with adsorption properties similar to those of central polyol units. Under these conditions Rƒ of polyol is only sensitive to the contents of hydroxyl groups (functionality), but is insensitive to molecular weight. The method developed may be used for determining impurities in oligomeric polyols of low functionality. For quantitative analysis use is made of the dependence of Rƒ of the “point” of the chromatographic spot on the amount q of the polyol contained. The linear relation between Rƒ and q is maintained in the concentration range which differs by 2 orders of magnitude and enables impurity content to be analysed with an accuracy of ∼ 3%.

A study was made of the composition according to functionality of polybutylene glycoladipates (PBGA) using special thin layer chromatographic methods and sheets coated with silica gel reinforced with gypsum. Linear and branched polyesters were completely separated in a benzene-ethanol (3 : 1 by vol.) solvent system. The use of thin layer chromatography made it possible to explain the effect of monofunctional impurities in 1,4-butanediol on the properties of PBGA. An increase in the content of monofunctional impurities in PBGA from 1 to 5% reduced molecular weight. The effect of the type of catalyst on composition according to functionality of PBGA was shown.

The mechanism of the thin-layer chromatography of oligomers based on the different adsorption activities of the end groups and the central units, characterized by adsorption energies −ϵe and −ϵc, is discussed. It is shown that the application of the concept of the critical adsorption energy, −ϵo, to the central oligomer units makes it possible to distinguish three cases of the molecular weight dependence of RF values: at −ϵo > −ϵc and −ϵo < −ϵc we have a negative and positive molecular weight dependence of RF values, respectively, while at −ϵo = −ϵc the RF values do not depend on molecular weight. In the last instance, thin-layer chromatography can be used for the separation of oligomers on the basis of functional groups and degree of branching independent of their molecular weights. For the separation of oligomers on the basis of molecular weight thin-layer chromatography, hydroxyl end groups should be blocked in the case of poor adsorption activity of the central units. In this instance the second type of molecular weight dependence of RF values is observed. A quantitative method for the determination of low-functionality impurities monools and poly(propylene oxide)diols in oligomers based on the chromatographic spot length is suggested.

A study was made of the molecular heterogeneity of polyethers, propylene oxide-ethylene oxide copolymers. Thin layer chromatography using silica gel was applied. Separation is based on the difference in adsorption interaction of hydroxyethyl and hydroxypropyl units in the molecule. Four solvent systems were selected to separate both homopolymers of propylene oxide and copolymers with broad distribution according to composition. It was found possible to use thin layer chromatography to determine the composition and structure of copolymers.