Structural features and physicochemical properties of promising diamond-containing modifier fillers for industrial polymers, namely, detonation nanodiamonds and nanodiamond soot, are considered. Experimental results demonstrating the possibility to create prepregs with the use of the carbon fabric 1.5 К and a detonation-diamond soot-modified binder based on the epoxy-resin mixture Epikote828/Epikote154 with an anhydride-type curing agent are presented. The rheological characteristics of the diamond-sootmodified binder remain practically the same after storage for 2 or 3 days at room temperature. The dependence of the glass-transition temperatures of the binders on the content of diamond soot in the concentration range 0.025–0.1 wt % is studied, and the correlation between these results and the mechanical characteristics (breaking strength, flexural strength, and crack resistance) of the cured binders is ascertained. Within the entire range of diamond-soot concentrations, the parameters of gelation are determined and the activation energies of this process are calculated.

Комплексом физико-химических методов изучено влияние наноалмазной шихты на условия и механизм отверждения эпоксидного связующего для систем Epkote 828-изометилтетрагидрофталевый ангидрид и Epikote 828-Epikote 154-изометилтетрагидрофталевый ангидрид–эндиковый ангоидрид– ундецилимидазол. Методом малоуглового рентгеновского рассеяния исследовано распределение наноразмерных частиц в отвержденной эпоксидной матрице с различным содержанием наполнителя. Методом высокотемпературной ИК-фурье-спектроскопии показано, что наноалмазная шихта катализирует отверждение эпоксидного связующего с получением полиэфира как продукта реакции. Для смеси эпоксидных смол, отверждаемых ангидридами, добавление наноалмазной шихты приводит к росту конверсии ангидридных групп отвердителя. Количество полиэфира как продукта реакции при этом не меняется, что может быть следствием взаимодействия отвердителя (изо-метилтетрагидрофталевого ангидрида и эндикового ангидрида) с активной поверхностью шихты и эпоксидными группами связующего с образованием переходных комплексов. В результате такого взаимодействия изменяются реологические характеристики композиции: при длительном хранении эпоксидного связующего без наполнителя его вязкость увеличивается, а введение алмазной шихты стабилизирует систему.

The presented study is dedicated to evaluation of the effect of two types of detonation nanodiamond soot particles differing in surface charge polarity on the adhesion strength of the interphase between highly oriented poly(vinyl alcohol) fibers and epoxy matrix. Two major strategies for such modification are considered: 1—only one of the constituent components (either matrix or fiber) is being impregnated with nanodiamond soot; 2—both components of the composite system are being modified with nanodiamond soot. The second approach is further complicated by the fact that fiber and epoxy matrix can either be modified by the same type of nanodiamond soot (i.e. fiber and matrix both contain particles of equal surface polarity) or the modification is being carried out by using different types of nanodiamond soot for impregnating the fiber and the matrix (which results in these components containing disperse particles of the same morphology but opposite surface charge polarity). In the presented study both approaches are addressed.

The effect of a nanodiamond soot on the conditions and mechanism of cure of epoxy binders is studied for the systems Epikote 828-isomethyltetrahydrophthalic anhydride and Epikote 828-Epikote 154-isomethyltetrahydrophthalic anhydride-endic anhydride-undecylimidazole with the use of a combination of physicochemical methods. The distribution of nanosized particles in the cured epoxy matrixes containing various amounts of the filler is investigated via small-angle X-ray scattering. High-temperature FTIR spectroscopy studies show that the nanodiamond soot catalyzes the curing of the epoxy binders and gives rise to polyester as a reaction product. For the mixture of epoxy resins cured by anhydrides, addition of the nanodiamond soot entails an increase in the conversion of anhydride groups of the binder. In this case, the amount of polyester as a reaction product does not change. This circumstance may be explained by the interaction of the curing agent (isomethyltetrahydrophthalic anhydride and endic anhydride) with the active surface of the soot and epoxy groups of the binder and by the accompanying formation of transition complexes. As a result of this interaction, the rheological characteristics of the composite change: During long-term storage of the epoxy binder without any filler, its viscosity increases and the addition of the diamond charge stabilizes the system.