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Blends of inorganic polyoxides and hydrocarbon polymers, with the concentrations of the components varied widely and with the advantages of both classes of polymers being retained, offer a means for materials design.A promising approach to the design of such materials is to use low-melting inorganic polymers, in particular, boron polyoxides: the softening temperatures and melt viscosities of boron polyoxides are close to these parameters for organic polymers (the second components of blends), which allows conventional plastic technologies to be employed.As the inorganic component, we used boric acid (BA). BA is a three-function monomer, whose polycondensation yields boron polyoxide (boron anhydride, in which the concentration of unreacted OH groups can reach significant values because of the incompletion of the reaction).Boron anhydride (Çé 1.5 ) n (éç) xn (where x < 0.3) is a branched low-molecular-weight polymer containing reactive B-OH groups in its macromolecules; these groups have a weak acid character and can chemically react with organic compounds [1].It was shown previously [2] that boron anhydride in blends with poly(ethylene) substantially affects not only the rate of thermal oxidative destruction of poly(ethylene) but also the routes of the accompanying chemical processes.Here, we consider the thermal behavior of poly(vinyl alcohol) (PVA) as the organic component in blends with boric acid; the OH groups of PVA are reactive toward B-OH groups.The subjects of the study were powdered blends of BA and PVA and their reaction products obtained by dissolution of each component in distilled water at T = 70°ë followed by mixing their 1.5% solutions at room temperature and concentrating the homogeneous mixture at T = 90-100°ë . The BA used was reagent grade (Reakhim) and PVA was from DuPont ( M n = 300000, no more than 2% acetate groups).The thermal destruction of the precursor PVA was studied using thermogravimetry (TG) on a Derivatograph Q 1500 thermoanalytical balance under an inert (argon) atmosphere and in air; the sample weight was 10 mg. The heats of reactions were measured on a DuPont DSC instrument under argon and in air. The heating rate in both cases was 10 K/min. Chemical reactions between the components of the blend were determined by means of NMR spectroscopy. 11 B NMR spectra were recorded in a B 0 = 7.04 T field on a Bruker MSL-300 spectrometer using probes with horizontal sample orientation [3].

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