The analysis of hydroxyl groups in polymers is reviewed. Recent achievements of chemical, physico-chemical and physical methods for the determination of hydroxyl groups and their differentiation by reactivity have been examined. Particularly, infrared spectroscopy and nuclear magnetic resonance used for this determination are considered. Die Bestimmung yon Hydroxylgruppen in Polymeren. FortschrittsberichtIn dem Bericht werden neuere Entwicklungen chemischer, physikalisch-chemischer und physikalischer Methoden zur Bestimmung von Hydroxylgruppen und ihrer Differenzierung hinsichtlich der Reaktivitat dargestellt. Insbesondere wird die Anwendung der Infrarotspektroskopie und der magnetischen Kernresonanz behandelt. Onpeaenenue zur3powuJabnwx zpynn 8 nom.wepax. O630p 0 6 3 0~ IIOCBfiQeH aHaJIH8y rHAPOKCHnbHhIX rpynn B IIOJIEiMepaX. PaCCMOTpeHbI IlOCJIeAHlle AOCTEiXeHllfi XHMH9eCKHX, @H3HHO-XHMH9eCHHX Ei @H3H4eCKHX MeTOAOB KOJIEi9eCTBeHHOrO OIIpeAeneHElH I' HApOKCHJIbHbIX I'pyIIII H HX AH@-@epeHqEi~EiEinOpeaKqHOHHOltCnOCO6HOCTH. ~C O 6 O~B H l l M~H H~~~~j I~H O H H @~~K~~C H O~C I I~K T~O C MarHHTHOMY pe30HaHCy. Chemical methods of analysisChemical methods a r e simple a n d accessible, t h e y do not require special equipment a n d expensive instruments. At t h e same t i m e t h e y a r e rather time-consuming a n d require considerable amounts of t h e substance t o be analyzed. These methods can mainly give quantitative information. If t h e differentiation of HG is necessary, they become much more time-consuming. Recently t h e effective methods of chemical analysis have appeared which enable HG t o b e determined rapidly a n d exactly enough. Acylation of HG is most widely used, its application for polymers is detailed in t h e handbooks o n polymer analysis. The classical acylation procedure [27, 281 uses acetic (AA) or phthalic anhydride (PA) in pyridine solution, t h e latter being t h e solvent and catalyst of t h e reaction. T h e use of propionic [29], succinic [30--321, nitrobenzoic [33], osulfobenzoic [34], nitrophthalic [35]anhydrides for t h e same purpose is described. As a rule, primary a n d secondary HG a r e fully acylated within 1 t o 2 h a t 100 t o 115°C. Pyromellitic dianhydride (PMDA) [36-381 is more effective. It has as high activity as AA a n d does not interact with aldehyde groups a n d phenolic HG which is characteristic of PA. Dimethylsulfoxide (DMSO) is especially recommended as a solvent [37].T o acylate HG, more active acyl chlorides can b e used. BOIKO and GRISHCHENKO:Deterinination of liydroryl groups in polymers. Review Acta Polymcrica 36 (1985) Nr. 9

The work was aimed at studying the effects of combining epoxidized soybean oil (ESO) with standard bisphenol type A epoxy resin (ED-20). The ED-20 / ESO ratios were 100/0, 90/10, 95/15 and 80/20 (wt%). The system was cured with amine hardener mono(cyanethyl) diethylenetriamine (MCDT), triethanolamine (TEA) and mixture thereof (TEA + MCDT) at different curing temperatures. The choice was based on the hardener’s ability to open oxirane cycles, form a spatial network and initiate several parallel reactions. The viscoelastic properties, mechanical properties (tensile strength and elongation) were studied the density of obtained ED-20 / ESO samples was determined. The results showed that the introduction of ESO into epoxy resin ED-20 was accompanied by significant changes in the curing and final properties of the samples. It was shown that the physic- mechanical properties of polymer compositions ED-20 / ESO were determined by both the ESO content and the temperature of curing Depending on the selected curing mode, the addition of 5–10 wt.% of ESO increased the tensile strength relative to the σр value of the original epoxy matrix. The values of relative elongation increased significantly at 15-20 wt.% of ESO. By the method of dynamic mechanical analysis it was shown that the increase of ESO content leads to plasticization of epoxy composition and to reduction of crosslinking density. It was determined that 5-10 wt.% was the optimal concentration of ESO, at which the epoxy composition had improved physical and mechanical properties Further increase of ESO content reduced the crosslinking density and increased the defectiveness of the epoxy polymer, which causes premature failure in weak places of the structure under load.