scholarly journals Reinforcing of Composite Materials on the Basis of Fresh Ice and Natural Origin Additives

Author(s):  
A S Syromyatnikova ◽  
A M Bol’shakov ◽  
A V Alekseeva
2021 ◽  
Vol 63 (2) ◽  
pp. 219-226
Author(s):  
T. S. Demina ◽  
T. A. Akopova ◽  
A. N. Zelenetsky

Abstract The transition to green chemistry and biodegradable polymers is a logical stage in the development of modern chemical science and technology. In the framework of this review, the advantages, disadvantages, and potential of biodegradable polymers of synthetic and natural origin are compared using the example of polylactide and chitosan as traditional representatives of these classes of polymers, and the possibilities of their combination via obtaining composite materials or copolymers are assessed. The mechanochemical approach to the synthesis of graft copolymers of chitosan with oligolactides/polylactides is considered in more detail.


Author(s):  
Ю. О. Будаш ◽  
Є. В. Кучеренко ◽  
В. П. Плаван ◽  
Я. В. Фещенко ◽  
О. І. Верейко

Comparison of dimensional characteristics of various non-wood fibers (flax, hemp, bamboo, cotton), which can be used as an additional component in the production of non-woven composite materials from synthetic fibrous waste. The structure of the fibers was studied by optical polarization microscopy. The dimensional characteristics of the fibers were determined by the method of analyzing digital images, followed by statistical processing and graphical analysis of the obtained data. A quantitative comparative analysis of the transverse dimensions and distribution for this indicator for non-wood fibers of various natural origin: flax, hemp, bamboo, cotton. It has been established that the average transverse dimensions of the initial fibers of flax and hemp are higher than for bamboo and cotton fibers with greater variability of this index and a pronounced asymmetry of the distribution towards valuesgreater than the average. Based on a detailed statistical analysis of microscopic images, differences in the transverse dimensions of non-wood fibers of different natural origin are established.  The results obtained can be used to produce nonwoven composite materials with predictable properties.


2020 ◽  
Vol 28 (1(139)) ◽  
pp. 123-129
Author(s):  
Krystyna Wrześniewska-Tosik ◽  
Tomasz Mik ◽  
Ewa Wesołowska ◽  
Sarah Montes ◽  
Tomasz Kowalewski ◽  
...  

Various methods of nonwoven composite materials manufacturing are known. One such method is the well-known technique called spun-bonding. The production technology for composite nonwoven by the spun-bond method is known, but the technique of introducing an additive in the form of shredded wastes of natural origin so as to obtain a composite nonwoven fabric with interesting functional properties is new. The article describes a method of producing an innovative composite nonwoven using the spun-bond technique. As a result of incorporating various additives into the nonwoven structure, composite nonwovens with modified properties are obtained. Composite nonwovens, depending on the additive used, can be utilised as filtration material in the construction, agriculture or automotive industry.


Author(s):  
R.R. Russell

Transmission electron microscopy of metallic/intermetallic composite materials is most challenging since the microscopist typically has great difficulty preparing specimens with uniform electron thin areas in adjacent phases. The application of ion milling for thinning foils from such materials has been quite effective. Although composite specimens prepared by ion milling have yielded much microstructural information, this technique has some inherent drawbacks such as the possible generation of ion damage near sample surfaces.


Author(s):  
K.P.D. Lagerlof

Although most materials contain more than one phase, and thus are multiphase materials, the definition of composite materials is commonly used to describe those materials containing more than one phase deliberately added to obtain certain desired physical properties. Composite materials are often classified according to their application, i.e. structural composites and electronic composites, but may also be classified according to the type of compounds making up the composite, i.e. metal/ceramic, ceramic/ceramie and metal/semiconductor composites. For structural composites it is also common to refer to the type of structural reinforcement; whisker-reinforced, fiber-reinforced, or particulate reinforced composites [1-4].For all types of composite materials, it is of fundamental importance to understand the relationship between the microstructure and the observed physical properties, and it is therefore vital to properly characterize the microstructure. The interfaces separating the different phases comprising the composite are of particular interest to understand. In structural composites the interface is often the weakest part, where fracture will nucleate, and in electronic composites structural defects at or near the interface will affect the critical electronic properties.


1986 ◽  
Vol 55 (02) ◽  
pp. 271-275 ◽  
Author(s):  
Helen Ireland ◽  
D A Lane ◽  
Angela Flynn ◽  
E Anastassiades ◽  
J R Curtis

SummaryThe heparinoid of natural origin Org 10172 has anti-factor Xa activity but minimal anti-thrombin activity, and little effect upon broad spectrum assays such as the KCCT in vitro. Its anticoagulant effects have been compared to those of commercial heparin in 7 patients undergoing haemodialysis for chronic renal failure. Commercial heparin was administered in a dose (5,000 iu bolus + 1,500 iu/hour continuous iv infusion) previously shown to inhibit fibrin formation during haemodialysis. This produced mean anti-factor Xa levels in plasma between 0.7-1.0 iu/ml and largely suppressed fibrin formation for 5 h dialysis measured as mean FPA levels in plasma. Administration of Org 10172 as a bolus of 1,350 anti-factor Xa u or 2,000-2,400 anti-factor Xa u produced plasma anti-factor Xa levels of less than 0.5 u/ml and allowed fibrin clot and FPA generation during dialysis. Org 10172 administered as a bolus dose of 4,000-4,800 anti-factor Xa u produced mean anti-factor Xa levels of greater than 0.5 u/ml, allowed dialysis of 6 patients for 5 h and appreciably suppressed FPA generation during dialysis, with little effect on the KCCT.It is concluded that the anti-factor Xa activity of Org 10172 may reflect its ability to inhibit fibrin during dialysis and that single bolus injection of Org 10172 may be a useful alternative method of achieving anticoagulation.


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