scholarly journals Foam Polymers in Multifunctional Insulating Coatings

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3698
Author(s):  
Ter-Zakaryan K. A. ◽  
Zhukov A. D. ◽  
Bobrova E. Yu. ◽  
Bessonov I. V. ◽  
Mednikova E. A.
Keyword(s):  
Thermal Conductivity ◽  
Water Absorption ◽  
Moisture Absorption ◽  
Water Immersion ◽  
Average Density ◽  
Operating Conditions ◽  
Insulating Materials ◽  
Longitudinal Tensile Strength ◽  
Metallized Coating ◽  
Outer Perimeter

The application of foamed polymers as one of the components of insulating coatings allows to solve the problems of energy saving and creation of optimal operating conditions for constructions. The systems of application of energy-efficient heat-insulating materials must consider both the particularities of the insulating materials and the functional orientation of the constructions. The implementation of the concept of seamless insulating coatings implies the achievement of thermal effect and reduction in air permeability both by means of the application of thermal insulation with low thermal conductivity and the minimization of junctions between separate elements of the insulating coating, which is achieved using elastic foamed polymers and, first of all, polyethylene foam. Construction of seamless insulating coatings creates practically impermeable heat, vapor, and water barriers along the outer perimeter of the insulated object. Multilayer products based on polyethylene foam represent a relatively new material—a fact that requires examination of their properties, as well as under various operating conditions, and development of a methodology for evaluation of the operational resistance of these materials in structures of different purposes, including cold conservation. The performed tests have shown that the compressive strength at 10% deformation is determined by the function of load application area and varies from 70 kPa during the test of cube samples of 10 × 10 × 10 in size to 260 kPa for areas exceeding 100 m2. The longitudinal tensile strength amounts to 80–92 kPa, and the strength of the weld seam is equal to 29–32 kPa. It has been established that the values of thermal conductivity of polyethylene foam with an average density of 18–20 kg/m3 amounts to 0.032–0.034 W/(m·K), diffusion moisture absorption is equal to 0.44 kg/m2 without a metallized coating and 0.37 kg/m2 with a metallized coating; water absorption after partial immersion in water for 24 h amounts to 0.013 kg/m2; water absorption by volume after complete water immersion for 28 days is equal to 0.96%. The material does not practically change its properties under conditions of long-term temperature alteration from −60 to +70 °C. The developed and implemented insulation systems for protective surfaces of framed construction objects, rubbhalls and frameless structures, floating floors, indoor ice rinks, and snow conservation systems are presented.

scholarly journals Effect of Moisture Absorption Behavior on Mechanical Properties of Basalt Fibre Reinforced Polymer Matrix Composites

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Amuthakkannan Pandian ◽  
Manikandan Vairavan ◽  
Winowlin Jappes Jebbas Thangaiah ◽  
Marimuthu Uthayakumar
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Moisture Absorption ◽  
Polymer Matrix Composites ◽  
Unsaturated Polyester ◽  
Water Immersion ◽  
Polymeric Materials ◽  
Matrix Composites ◽  
Basalt Fibre ◽  
Saturation State

The study of mechanical properties of fibre reinforced polymeric materials under different environmental conditions is much important. This is because materials with superior ageing resistance can be satisfactorily durable. Moisture effects in fibre reinforced plastic composites have been widely studied. Basalt fibre reinforced unsaturated polyester resin composites were subjected to water immersion tests using both sea and normal water in order to study the effects of water absorption behavior on mechanical properties. Composites specimens containing woven basalt, short basalt, and alkaline and acid treated basalt fibres were prepared. Water absorption tests were conducted by immersing specimens in water at room temperature for different time periods till they reached their saturation state. The tensile, flexural, and impact properties of water immersed specimens were conducted and compared with dry specimens as per the ASTM standard. It is concluded that the water uptake of basalt fibre is considerable loss in the mechanical properties of the composites.

scholarly journals Water Absorption Behavior and Impact Strength of PVC/Wood Flour Composites

2010 ◽  
Vol 4 (3) ◽  
pp. 225-229 ◽  
Author(s):  
Gisele Iulianelli ◽  
◽  
Maria Bruno Tavares ◽  
Leandro Luetkmeyer ◽  
◽  
...  
Keyword(s):  
Impact Strength ◽  
Water Absorption ◽  
Moisture Absorption ◽  
Wood Flour ◽  
Chemical Constituents ◽  
Water Immersion ◽  
Control Sample ◽  
Maximum Water ◽  
The Difference ◽  
Wood Content

PVC/wood flour composites were prepared by compression molding using sapwood and heartwood from Angelin Pedra as filler. The composites specimens were subjected to water immersion and impact tests. The results showed that the water absorption of all composites increased slightly with increasing immersion time and wood content. However, the values were considerably low compared with control sample, common solid woods and wood plastic composites reported in literature. PVC/sapwood composites showed slightly higher values for moisture absorption ability due to the difference in chemical constituents’ ratio. PVC compound and PVC/sapwood composite containing 10 phr of wood flour exhibited maximum water absorption in 63 days and it corresponded to 0.25 % and 0.58 % weight gain, respectively. In relation to impact test, the results indicated that impact property was affected by wood content and less by wood type. Composites containing 10 phr of wood content showed greater impact strength (decreased by around 60 %) than those prepared with 25 and 40 phr of wood flour content (decreased approximately by 75 %). In general the composites prepared with 10 phr of wood flour content exhibited a better performance in both parameters measured in this study.

The Measurement of Water Absorption by Rubber

1933 ◽  
Vol 6 (1) ◽  
pp. 24-32
Author(s):  
H. A. Daynes
Keyword(s):  
Water Absorption ◽  
Moisture Absorption ◽  
Recent Literature ◽  
Hot Water ◽  
Raw Material ◽  
Insulating Materials ◽  
Vulcanized Rubber ◽  
Rate Of Absorption ◽  
The Subject ◽  
Selection Of

Abstract The absorption of water by rubber has occupied a prominent place in recent literature, especially in connection with cable and other insulating materials, since it is well known that their electrical properties are adversely affected by absorbed moisture. Many other classes of rubber goods and materials also are subject to water absorption, e. g., rubber soling, tires, washers, packings, hose, tank and grinding mill linings, hot-water bottles, and surgical goods. Apart from the performance, of such articles in service, moisture absorption is important in relation to factory operations, such as drying and vulcanizing, and to storage and mechanical testing. This paper deals with the selection of a method for measuring the amount of water absorbed by rubber when saturation has been reached. In the work for which the method was developed, the rate of absorption was of no interest; but it was necessary to correlate the water absorbed by the vulcanized product with that absorbed by the raw material, so that a method was required which could be applied equally well to raw rubber, vulcanized rubber, and ebonite. It is not proposed to discuss in detail the mechanism of absorption. The literature has already been briefly reviewed by Lowry and Kohman (J. Phys. Chem., 31, 23 (1927)), who have been largely responsible for present ideas on the subject. It will be sufficient to recall that the process is a reversible one, and that the amount absorbed at any temperature depends on the humidity of the surrounding gas and the nature of the rubber.

Dome House Insulation Systems

2020 ◽  
Vol 992 ◽  
pp. 48-53
Author(s):  
E. Shokodko ◽  
Ekaterina Yu. Bobrova ◽  
E. Zinovyeva ◽  
Alexey D. Zhukov
Keyword(s):  
Water Absorption ◽  
Moisture Absorption ◽  
Experimental Studies ◽  
Adhesive Layer ◽  
Average Density ◽  
Hot Air ◽  
Living Space ◽  
Diffusion Characteristics ◽  
Insulation Systems ◽  
Interior Walls

The article presents the results of studying the possibility of using the insulation systems in the structures of rural buildings of various functional purposes, including the creating the multifunctional objects. A vegetarium dome house is considered, which unites a living area and greenhouses. The planning solution of the multipurpose domed house involves the formation of the effective insulation systems for the interior walls, protecting the living space of the interior from the heat-moisture and phytoaggressive features of the greenhouse exterior. A comparative analysis of possible heat-, water-and vapor-insulating materials for an insulating membrane has established the expedience of using the rolled foam-polyethylene fixed by an adhesive method on the external surfaces of the internal walls. Experimental studies have established that polyethylene foam with an average density of 18–20 kg/m3 has the following characteristics: the diffusion moisture absorption without any coating is 0,44 kg/m2; the diffusion moisture absorption with a metalized coating is 0,37 kg/m2; water absorption upon partial immersion in water for 24 hours is 0,013 kg/m2; volume water absorption with full immersion in water for 28 days is 0,96%. The nature of the destruction of the contact surface “foam polyethylene-metal” is cohesive in the adhesive layer, and the destructive stress is 12–17 kPa. A special feature of the polyethylene foam is the possibility of creating a jointless coating with minimal diffusion characteristics and with minimized cold bridges. The jointless cover is formed by combining the roll material into a lock, followed by hot air welding.

A Method for Predicting the Mean Thermal Conductivity of Insulating Materials at Other Than Experimental Conditions

1963 ◽  
Vol 85 (2) ◽  
pp. 185-186
Author(s):  
C. E. Jones
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Operating Conditions ◽  
Conductivity Data ◽  
Experimental Conditions ◽  
Insulating Materials ◽  
Thermal Conductivity Data ◽  
Test Conditions ◽  
The Mean

A procedure whereby experimental thermal conductivity data can be readily extrapolated to operating conditions quite different from test conditions is presented. Use of this technique can also lessen the amount of experimental data that must be collected and ease experimental problems.

scholarly journals Ultralight large grain porous material - expanded obsidian

2019 ◽  
Vol 97 ◽  
pp. 02038 ◽  
Author(s):  
Artsruni Safaryan ◽  
Tamara Sargsyan ◽  
Marine Kalantaryan ◽  
Hripsime Melyan
Keyword(s):  
Thermal Conductivity ◽  
Heat Treatment ◽  
Compressive Strength ◽  
Porous Material ◽  
Heat Resistance ◽  
Thermal Conductivity Coefficient ◽  
Lightweight Concrete ◽  
Average Density ◽  
Waste Products ◽  
Insulating Materials

In the production of crushed stone, lithoidal pumice and perlite sand, it is advisable to separate and segregate the obsidian. Wherein, the separated obsidian is converted into production waste. By the expansion of obsidian it is possible to obtain an ultralight large grain porous material and thereby solve environmental issues - to dispose of waste products. The expansion of volcanic glass (obsidian) occurs due to gases, primary (magmatic) and secondary (hydraulic) water, which is located in the pores. During the expansion, under heat treatment, the gases expand about 4 ... 5 times in the pores, which contributes the expansion. Expanded obsidian can be used as a filler for lightweight concrete. Obsidian is expanded at temperatures of 1050-115°C. The lowest average density of 200 - 350 kg / m3 (in a piece) is obtained by heat treatment of obsidian with a particle size of 5 to 20 mm for a duration of 3-10 minutes. Depending on the requirements for lightweight aggregates, by adjusting the firing temperature and duration, it is possible to obtain expanded obsidian with the necessary physical and mechanical properties. It is revealed that more durable concretes are obtained with cement consumption of 350 ... 380 kg. Depending on the average density of lightweight concrete 400 .. 1350 kg/m3, the compressive strength is 0.2 ... 16,9 MPa. Light monolithic products with improved characteristics of heat resistance and thermistance, having an average density of 180-200 kg/m3, compressive strength of 1.2–1.5 MPa, frost resistance of 25 cycles, after which the strength changes to 1.0–1.3 MPa, heat resistance to 800–850°C, and thermistance to 600–650°C. By the thermal conductivity coefficient determination it was possible to reveal that in the temperature range of 20-60°C, the thermal conductivity coefficient changes by 0.002 W/mK, i.e. from 0.044 to 0.046 w/mK. Thus, the obtained monolithic blocks can be very successfully used as heat-insulating materials, which will retain their properties throughout the operation of the facilities. The requirements for mechanical strength and decorative properties for sound-absorbing materials compared to thermal insulating materials are higher, since they are used for internal linings. Thus, the obtained monolithic blocks can be very successfully used as heat-insulating materials, which will retain their properties throughout the operation of the facilities.

scholarly journals OPTIMIZATION OF PROTECTIVE COATING COMPONENTS OF THERMOMODIFIED WOOD TO THE EXPOSURE OF WATER

2021 ◽  
pp. 101-109
Author(s):  
Yu. Tsapko ◽  
◽  
A.Yu. Gorbachova ◽  
S.N. Mazurchuk ◽  
O. Bondarenko ◽  
...  
Keyword(s):  
Water Absorption ◽  
Protective Coating ◽  
Moisture Absorption ◽  
Thermal Modification ◽  
Wood Products ◽  
Operating Conditions ◽  
Photochemical Degradation ◽  
Thermally Modified Wood ◽  
Wood Surfaces ◽  
Modified Wood

Abstract. Paints and varnishes are used to a large extent to protect wood surfaces in outdoor conditions, as they are easy to maintain and reapply. Also, when developing a coating, manufacturers are guided by the need to obtain a number of properties that generally determine its ability to protect against moisture. To obtain a protective coating that meets the specified requirements, it is necessary that the components that make up the coating belong directly to the group of protective materials or form such compounds under operating conditions, be able to adhere to the surface of the product. It was found that thermal modification provides a decrease in water absorption of wood. Additional processing of the wood surface helps to reduce moisture absorption by 2 times, and for samples modified at a temperature of 220 °C – 3 times. Geometric dimensional stability is also improved by a factor of 2. The effect of heat treatment on the water absorption of wood is somewhat less – for samples modified at 190 and 220 °C for more than 10 hours. Protective substances for thermally modified wood provided similar protection of open thermally modified surfaces of wood from the effects of water. The positive effect of thermal modification on a decrease in the level of water absorption has been established. It has been proven that it is temperature that has a significant effect on such changes. Since the protective coating is also susceptible to photochemical degradation, it is very important to renew it in a timely manner in accordance with the manufacturer's instructions for the pleasant appearance of wood surfaces during external use. The optimal ratio of components in the surface layer of thermally modified wood has been determined, which ensures the fulfillment of the task, namely for a mixture of oil and wax: the density of a wood – 724 kg/m3; oils – 70.0%; wax – 17.5%. Therefore, such treatment is beneficial for the protection and aesthetic appeal of wood products.

scholarly journals Insulation Systems of Frame Cottages

2019 ◽  
pp. 122-127 ◽  
Author(s):  
Alexey D. Zhukov ◽  
Karapet A. Ter-Zakaryan ◽  
Igor V. Bessonov ◽  
Vyacheslav S. Semenov ◽  
Alexey V. Starostin
Keyword(s):  
Tensile Strength ◽  
Water Absorption ◽  
Moisture Absorption ◽  
Adhesive Layer ◽  
Longitudinal Direction ◽  
Mineral Wool ◽  
Partial Immersion ◽  
Insulation Systems ◽  
Metallized Coating ◽  
Mandatory Placement

The article presents studies of the exploitation characteristics of the material, the results of a full-scale survey of a residential private house insulated with expanded polyethylene, as well as the main design solutions for the insulation of a frame cottage. The features of insulation systems of low-rise buildings, including those with a frame-bearing carrier system, are considered. It has been substantiated that the use as thermal insulation of mineral-wool plates used on non-loaded structures assumes the mandatory placement of vapor barrier (usually plastic film) from the inside of the insulated surface and the windproof membrane outside. The use of a rolled foamed polyethylene as an insulating material makes it possible to realize an insulating sheath without additional layers. Experimental determinations of diffusion moisture absorption, water absorption upon partial immersion in water, water absorption upon full immersion in water, tensile strength in the longitudinal direction, and adhesion strength of the adhesive layer to metal were performed. It was established that the diffusion moisture absorption of samples of expanded polyethylene is 0.51-0.75%, and taking into account the weld it is 0.70-0.75%. Water absorption of samples when fully immersed in water does not exceed 0.96% by volume. The tensile strength in the longitudinal direction for products with a metallized coating is 80-92 kPa, without a metallized coating - 80-87 kPa, and for a weld - 29-32 kPa. A field survey showed that the humidity of the pine timber is within the normative. The expediency of warming only the outer coating of expanded polyethylene of the calculated thickness without filling the frame is justified, which, with standard air exchange and observance of the conditioning conditions, will be sufficient to maintain the microclimate in the room.

Parametric Study of Photovoltaic Thermal Solar Collector Using An Improved Parallel Flow

2020 ◽  
Vol 2 (1) ◽  
pp. 19-24
Author(s):  
Sakhr Mohammed Sultan ◽  
Chih Ping Tso ◽  
Ervina Efzan Mohd Noor ◽  
Fadhel Mustafa Ibrahim ◽  
Saqaff Ahmed Alkaff
Keyword(s):  
Thermal Conductivity ◽  
Energy Balance ◽  
Parametric Study ◽  
Solar Collector ◽  
Parallel Flow ◽  
Operating Conditions ◽  
Balance Equations ◽  
Conductivity Type ◽  
Pv Module ◽  
Sunny Weather

Photovoltaic Thermal Solar Collector (PVT) is a hybrid technology used to produce electricity and heat simultaneously. Current enhancements in PVT are to increase the electrical and thermal efficiencies. Many PVT factors such as type of absorber, thermal conductivity, type of PV module and operating conditions are important parameters that can control the PVT performance. In this paper, an analytical model, using energy balance equations, is studied for PVT with an improved parallel flow absorber. The performance is calculated for a typical sunny weather in Malaysia. It was found that the maximum electrical and thermal efficiencies are 12.9 % and 62.6 %, respectively. The maximum outlet water temperature is 59 oC.

Sign in / Sign up

Export Citation Format

Share Document