The Influence of Sub-Zero Conditions on the Mechanical Properties of Polylactide-Based Composites

Polylactide-based composites filled with waste fillers due to their sustainability are a subject of many current papers, in which their structural, mechanical, and thermal properties are evaluated. However, few studies focus on their behavior in low temperatures. In this paper, dynamic and quasi-static mechanical properties of polylactide-based composites filled with 10 wt% of linseed cake (a by-product of mechanical oil extraction from linseed) were evaluated at room temperature and at −40 °C by means of dynamic mechanical analysis (DMA), Charpy’s impact strength test and uniaxial tensile test. It was found that the effect of plasticization provided by the oil contained in the filler at room temperature is significantly reduced in sub-zero conditions due to solidification of the oil around −18 °C, as it was shown by differential scanning calorimetry (DSC) and DMA, but the overall mechanical performance of the polylactide-based composites was sufficient to enable their use in low-temperature applications.

Crystallization of polylactide-based green composites filled with oil-rich waste fillers

Polylactide is a highly demanded biopolymer, whose industrial application constantly increases. Its disadvantages such as brittleness and slow crystallization rate can be overcome by application of different additives. Because of environmental issues, using natural waste fillers as modifying agents for polylactide is especially interesting. In this study linseed cake, a byproduct of oil extraction from linseed, characterized by oil content of 0.9–39.8 wt.%, was added to polylactide to influence its crystallization behavior. The formation of the crystalline phase was studied by differential scanning calorimetry in isothermal and non-isothermal conditions and analyzed according to methods by Jeziorny, Ozawa, Mo and Avrami. The samples’ microstructures were observed using polarized light microscopy. The crystallization rate and Avrami exponent of samples crystallized in different conditions were evaluated. It was found that addition of 10 wt.% of linseed cake containing at least 17.7 wt.% oil notably changes the crystallization of polylactide, increasing its crystallinity and promoting the growth of crystallites.

Rumen digestion and productivity of bulls when using linseed cake and choline

We have studied the peculiarities of the processes of rumen digestion in bulls while feeding them linseed cake in combination with the “protected” form of choline. When linen cake and choline were included in the diet, the most favorable conditions for the development of microorganisms were created in the rumen of animals, which had an impact on the growth of live weight.

Effect of linseed cake on Yakutian horse nutrient and energy metabolisms in winter

В статье освещены результаты исследований влияния на организм лошадей повышения содержания в зимнем рационе полиненасыщенных жирных кислот посредством включения льняного жмыха в условиях Якутии. Опыт по изучению влияния рациона с льняным жмыхом проведён на физиологическом дворе ЯНИИСХ им. М. Г. Сафронова на меринах 1011 лет в течение 30 дней методом периодов. Изучен химический состав рационов (сена, овса посевного и льняного жмыха), используемых в опытах. Определено влияние скармливания данных рационов на переваримость питательных веществ и обмен энергии. Определено влияние льняного жмыха на биохимические показатели крови. Выявлено, что льняной жмых содержит значительно большее количества омега-3 и омега-6 жирных кислот по сравнению с овсом. При этом соотношение -3 к -6 составляет 1:2 в льняном жмыхе, когда как у овса 1:24. Анализ химического состава льняного жмыха показал его высокопереваримые кормовые качества. Так, льняной жмых превосходит сено по содержанию сырого протеина на 23, по содержанию сырого жира почти в 4 раза. А содержание клетчатки в льняном жмыхе в 4 раза ниже, чем в сене. Включение льняного жмыха в зимний рацион лошадей оказало положительное влияние на обменные процессы в организме лошади и перевариваемость кормов, особенно на переваримость сырого жира и БЭВ. Кроме того, большее содержание в жмыхе незаменимых -3 жирных кислот положительно повлияло на обмен энергии. Высокая переваримость основных питательных веществ привела к повышенному содержанию обменной энергии в 1 кг сухого вещества при включении в рацион льняного жмыха по сравнению с сено-овсяным рационом. This paper reports on the effect of high content of essential fatty acids in linseed cake on horse organism in winter. The experiment took place at the Yakut Agricultural Research Institute n. a. M. G. Safronov. Gelded horses of 1011 years old were tested for 30 days. Hay, oat and linseed cake chemical compositions were analyzed. Fodder influence was tested on digestion processes and energy metabolism. Blood parameters were checked after feeding horses with linseed cake. Linseed cake contained significantly more omega-3 and omega-6 fatty acids than oats. Ratio of -3 to -6 amounted to 1:2 in linseed cake, while in oats 1:24. Chemical composition analysis showed high digestibility of linseed cake. Linseed cake exceeded hay in crude protein content by 23, and in crude fat almost by 4 times. Fiber concentration was 4 times less than in hay. Feeding horses with linseed cake positively affected their metabolism and feed digestibility, particularly decompositions of crude fat and nitrogen-free extractive substances. Additionally, high content of -3 fatty acids had positive effect on energy metabolism. High digestibility of main nutrients in linseed cake increased exchange energy content in 1 kg of dry matter, compared to the hay-oat diet.

Accelerated Weathering of Polylactide-Based Composites Filled with Linseed Cake: The Influence of Time and Oil Content within the Filler

This paper presents the effects of accelerated weathering on the properties of polylactide (PLA) composites filled with linseed cake. The particle-shaped waste filler with different linseed oil content (0.9–39.8 wt %) was incorporated with constant amount of 10 wt % to a polymeric matrix and subjected to accelerated weathering tests with different exposition times. The structure of the composites, their mechanical, thermal, and thermo-mechanical properties were evaluated by means of scanning electron microscopy, tensile test, dynamic mechanical thermal analysis, and differential scanning calorimetry prior to and after weathering. The results of the measurements were analyzed in reference to the amount of crude oil contained in the filler. The behavior of the multiphase composite during weathering was described. It was found that the oil-rich samples during the first stage of the process showed increased resistance to hydrolytic degradation due to their relatively high crystallinity. The presence of water and elevated temperatures caused swelling of the filler and cracking of the polymeric matrix. Those discontinuities enabled the plasticizing oil to be rinsed out of the composite and thus water penetrated into the samples. As a result, the PLA-based composites containing oil-rich linseed cake were found to be more vulnerable to hydrolytic degradation in a longer time.

Balance of protein supplements according to the criterion of convertible protein

The main sources of vegetable protein are seeds of legumes and oilseeds, which differ as by total content as by the quality. One of the least expensive and most rapid method of assessing the quality of protein is a chemical method, based on a comparative analysis of its amino acid composition, in particular, essential amino acids (EAA), and "ideal" protein. A widespread indicator of the proximity of the protein to the ideal is the minimum period, which shows how much of it can be used by the body for plastic needs (the main exchange and ensuring of body weight gain). Obviously, the more of this (convertible) protein in the product, the better (but not more than the daily value). One of the methods of obtaining a grain product with an increased convertible protein is blending, i.e. mixing in a certain proportion of different types of protein raw materials. In this case, the content of the converted mixture may be greater than in the components, and the excess less. The article presents a methodology for calculating the proportion of convertible protein in the product, as well as a new approach to the formation of effective mixtures. On the basis of this method, the results of the calculation of such mixtures on the example of a grain product with the use of collapsed white lupine, linseed cake and ginger seeds as components are shown. In all cases, there are rational proportions of the mixture, in which its convertible protein exceeds this figure in the component. The accuracy of the calculations largely depends on the accuracy of the total protein content and EAA.