scholarly journals Impact of microorganisms on mechanical properties changes of composite materials with organic filler

2021 ◽  
Author(s):  
Jarosław Szuszkiewicz

The beginning of the XXIst century is characterized by rapid development of polymer materials, including polymer composite materials, which consist of a natural organic filler (wood flour, sawdust, cellulose fiber, flax fiber, sisal fiber) and reinforcement carrier. In case of that kind of the fillers under the influence of weathering (humidity, temperature) they might be subject to biodegradation due to effect of microorganisms, including funguses, which are responsible for degradation of natural organic fillers. In case of the low melting temperature polymers (e.g. PE-LD) the processing temperature does not entirely eliminate some of the fungal spores. The paper has presented the research results of twelve months. The development of the microorganisms in the natural conditions was examined in a pure filler (sawdust) as well as in a composite. Simultaneously, change of one of the fundamental strength properties, which is the impact strength, was being tested. For the investigated composite the PE-LD as the matrix and a sawdust mixture of pine, larch and oak were used. The sawdust formed the composite in 30 %. The research results confirmed that in the natural conditions the microorganisms development depends on weathering which varies in the time of the year. The value of the V notch impact strength changed from 12.5 kJ/m2 for the composite in initial phase to the value of 6.7 kJ/m2 after twelve months operation, which is 50 %.

2021 ◽  
Vol 4 ◽  
pp. 121-126
Author(s):  
Rezza Ruzuqi ◽  
Victor Danny Waas

Composite material is a material that has a multi-phase system composed of reinforcing materials and matrix materials. Causes the composite materials to have advantages in various ways such as low density, high mechanical properties, performance comparable to metal, corrosion resistance, and easy to fabricate. In the marine and fisheries industry, composite materials made from fiber reinforcement, especially fiberglass, have proven to be very special and popular in boat construction because they have the advantage of being chemically inert (both applied in general and marine environments), light, strong, easy to print, and price competitiveness. Thus in this study, tensile and impact methods were used to determine the mechanical properties of fiberglass polymer composite materials. Each test is carried out on variations in the amount of fiberglass laminate CSM 300, CSM 450 and WR 600 and variations in weight percentage 99.5% -0.5%, 99% -1%, 98.5% -1, 5%, 98% -2% and 97.5%-2.5% have been used. The results showed that the greater the number of laminates, the greater the impact strength, which was 413,712 MPa, and the more the percentage of hardener, the greater the impact strength, which was 416,487 MPa. The results showed that the more laminate the tensile strength increased, which was 87.054 MPa, and the more the percentage of hardener, the lower the tensile strength, which was 73.921 MPa.


Author(s):  
I. V. Cheremukhina

The use of various physical influences is an economical and highly effective direction for regulating and improving the characteristics of the modified reinforced polymer composite materials developed in this work. The methods of energy effects studied in this work were used at the stage of impregnation of technical threads of various chemical nature with an oligomeric binder and a hardener (when preparing prepregs by the traditional method) or with a binder solution and a curing system (when preparing prepregs by the method of layered application of components) Based on the conducted research, a classification of the applied methods of physical modification according to the principle of the influence of energy fields is proposed. The studied methods of energy effects are divided into orienting and energetically energizing effects. The first group includes treatments with constant magnetic (PMP) or electric fields (PEP), and constant mechanical loads. The second group includes energy effects that have a wave nature (energetically energizing), and vibration, ultrasonic effects, and ultraviolet radiation are attributed to them. Modification methods of the first group contribute to a decrease in the mobility of binder molecules during curing, while the formation of branches of polymer chains occurs during the curing process, which leads to a predominant increase in the destructive stress during static bending. Energetically energizing effects contribute to the relative acceleration of the process of linear growth of polymer chains during curing, which is accompanied by the formation of a more sparsely cross-linked mesh structure, which leads to a predominant increase in impact strength. Of the two competing processes in the curing of epoxy oligomers, this one requires a higher activation energy, which is confirmed by the results of studies. Analyzing the results obtained, it can be concluded that the modification methods used in the work allow not only to obtain polymer composite materials with high strength characteristics, but also to directly adjust the properties of composites depending on the requirements for the products. Orienting modification methods lead to hardening of the resulting polymer composite material with a predominant increase in the destructive stress during static bending from 20 to 47%. When using energetically energizing influences in the technology of producing reinforced reactoplasts, the impact strength increases mainly from 19 to 40%.


2021 ◽  
pp. 096739112110080
Author(s):  
M Sermaraj ◽  
K Ramanathan ◽  
A Athijayamani

The used tyre rubber, scrap ceramic tiles and wood dust are largely dumped into landfills, which create environmental pollution to the surrounding. The recycling of tyre rubber is very limited, but it has good property to absorb the impact energy. Hence, these materials are used to prepare the composite in the present work. Composite materials were prepared by the resin transfer moulding method with different weight percentage of particles. The tensile, flexural and impact strength of composite specimens were compared with other combination of composites and also with the neat resin sample specimen. The tensile and flexural strength of composites were decreased with the addition of the rubber. But, the rubber particle with the ceramic in the resin matrix increases the impact strength of composite by 45.91% when compared with the neat resin sample. The addition of rubber enhances the impact strength of composite materials with all the combination of particles. The better distribution and good interfacial adhesion of particles with a resin matrix along the fractured surface were observed by the scanning electron microscope. And also, the nature of failure was identified by morphological studies.


2011 ◽  
Vol 250-253 ◽  
pp. 839-842
Author(s):  
Chun He Yu ◽  
Shao Rong Lu ◽  
Zhi You Yang ◽  
Kuo Liu ◽  
Xin Fan

In order to enhance the interfacial interactions between the sisal fiber (SF) and the polypropylene (PP) matrix, a water-solubility hyperdispersant which has amphipathic structure and flexible segment was used. Experimental results revealed that when the content of hyperdispersant is 5 percent, the impact strength of the composites was 27.4 kJ·m-2 and the flexural strength of SF/PP composites was 40.1 MPa, which was 64 and 34 wt% higher than that of unmodified systems, respectively. Meanwhile, the crystallinity of the composites also leads to an increase.


2019 ◽  
Vol 24 (4) ◽  
pp. 764-773
Author(s):  
Ji Zhao ◽  
Ning Zhi ◽  
Lu Ming

With the rapid development of the high-speed railway in China, the problems of the noise pollution induced by passing trains emerge. Theoretically, the V-shaped noise barrier is of pretty good performance of noise-reduction and load-shedding. To assess the practical aerodynamic deloading characteristics of the V-shaped noise barrier, a full-scale field test was carried out at three measuring-sections equipped with noise barriers of different heights. In order to quantify the research work, the impact strength and deloading rate were selected as indicators. The effects of train speeds, train types and barrier heights are studied. This study includes the variations of impact strength and deloading rate in vertical directions. Meanwhile, 2D numerical simulation research is conducted to analyze the experimental results from the angle of mechanism. It is observed that the aerodynamic load acting on the surface of the V-shaped noise barrier was weaker and more uniform compared with conventional barrier. The flow field distribution influenced the deloading characteristics of the V-shaped noise barrier significantly. Moreover, the load-shedding effect of V-shaped noise barrier, when CRH380AM passed by, was slightly better than CRH380A. The deloading rate improved with the increasing of the noise barrier height in general.


2020 ◽  
Vol 221 ◽  
pp. 01004
Author(s):  
Gulnaz Sabirova ◽  
Ruslan Safin ◽  
Shamil Mukhametzyanov ◽  
Nour Galyavetdinov

In environmental matters, one of the most pressing problems is the efficient disposal of polymeric materials that have a negative impact on the ecology of soils and oceans. A necessary condition for the sustainable development of industrial production and processing of polymer products is the transition to polymer materials based on renewable plant raw materials, in particular polylactides, polyhydroalkanates, etc. However, the technology for the production of these types of polymers is seriously inferior to synthetic polymers in the field of energy engineering. In this regard, research in the field of creating composite materials by introducing wood filler is currently particularly relevant. This research covers the results of stress-strain behavior of wood filled polylactic wood powder composite materials thermally modified by high temperatures ranged from 200 to 240 °С. Wood impact strength dependence is defined and static bending and composite density dependence on wood filler quantity and the temperature of its thermal modification is also established. It was specified that with the increasing of filler densification and its thermal treatment, the wood impact strength and composite density is decreasing, while with the reduced content of binding, the thermal modification of 200 °С has a positive impact on bending elastic coefficient. The conducted research allows identifying rational areas of use of composite materials as an effective factor in managing natural resources.


2010 ◽  
Vol 123-125 ◽  
pp. 1139-1142 ◽  
Author(s):  
Sawitri Srisuwan ◽  
Pranee Chumsamrong

In this study, the effects of weave type and fiber content on the physical properties of woven sisal fiber/epoxy composites were investigated. Sisal fibers used in this work were obtained from Nakhon Ratchasima, Thailand. Both untreated and alkali-treated fibers were employed. The woven sisal fibers were manufactured by hand weaving process. The fiber content in sisal fiber/epoxy composites were 3 wt.%, 5 wt.% and 10 wt.%. The composites were cured at room temperatures. In order to determine mechanical properties of the composites, flexural and impact tests were applied. Flexural strength and flexural modulus of all composites were higher than those of pure epoxy resin and tended to increase with increasing fiber content. The impact strength of all composites was lower than that of pure epoxy resin. The composites containing 10 wt.% sisal fibers showed the highest impact strength. There was no definite influence of weave type on flexural properties of the composites. At 3 and 5 wt.% fiber, the composites containing plain weave fibers seemed to show a higher impact strength than the composites containing other weave types.


2017 ◽  
Vol 36 (3) ◽  
pp. 782-787
Author(s):  
O Adekomaya ◽  
K Adama

The primary objective of this research work is to analyse the effect of fibre loading and orientation on the tensile and impact strength of the polymeric composite materials. Fibre reinforced composite materials have been reported to have attracted many applications in view of its low weight and superior strength when compared with the metal matrix composite. While researches have established the weight reduction of fibre reinforced polymer material, few works have reported the impact of orientation on the manufacturing of polymer composite. In this study, series of experimental works were done to demonstrate the manufacturing of glass-fibre reinforced epoxy resin with special attention on the influence of oriented reinforced composite material. The composites were manufactured using hand-lay technique with three different fibre loadings (10, 20, and 30 wt. %) and at two different fibre orientations (30o and 60o). Key of the finding drawn from this research form the basis of discussion and, composite with 60o fibre orientation showed better tensile strength when compared with the neat resin and other oriented (G10E30) fibre reinforced composite. Similar observations were also noticed on the impact strength of these composites which signify the improved mechanical properties of oriented reinforced composite materials. http://dx.doi.org/10.4314/njt.v36i3.17


2014 ◽  
Vol 880 ◽  
pp. 174-178 ◽  
Author(s):  
Nikita Martyushev ◽  
Yuriy N. Petrenko

Research results of cooling speed influence on structure and properties lead tin bronze are given in this article. Cooling speed changed by casting mold heating to various temperatures. Following the researches results it is shown that cooling speed growth leads to growth of hardness, strength on samples stretching. Decrease in cooling speed gives decrease in hardness and strength on stretching, but at the same time the impact strength of samples increases. Results of metalgraphic researches showed that such properties changes are connected with phase structure change of cast samples.


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