scholarly journals Sustainable insulating foams based on recycled polyurethanes from construction and demolition wastes

2021 ◽  
Vol 1 ◽  
pp. 37
Author(s):  
Edurne Elorza ◽  
Ibon Aranberri ◽  
Xiangming Zhou ◽  
Gediminas Kastiukas ◽  
Juan Antonio Alduncin

Background: Polyurethane (PU) foams contained in construction and demolition wastes (CDW) represent a great environmental impact, since they usually end in landfill or incineration processes. The goal of this work is to develop a way to formulate PU foams, maintaining (or ever improving) their performance, by the re-use of those industrial wastes. This procedure will allow minimize both the volume of disposal to be treated by other ways and the amount of pristine raw material needed to produce new PU foams. Methods: In this work, new rigid and soft polyurethane (PU) foams have been formulated with addition of recycled PU foams coming from demolition of buildings. Density, Fourier transform infrared analysis, compression properties and thermal conductivity were measured to characterize the resulting foams. Results: The work showed that addition of filler coming from recycled PU foams should be limited to low percentages, in order to allow good foam evolution from the reactants. Thermal conductivity values of modified rigid foams are worse than those of pristine foam, which is undesirable for thermal insulation purposes; however, in the case of soft foams, this parameter improved to some extent with low levels of recycled PU foam addition. Conclusions: The studied procedure could contribute to reduce the thermal conductivity of pristine soft PU foam, which would be of interest for applications where thermal insulation matters.

2021 ◽  
Vol 1 ◽  
pp. 37
Author(s):  
Edurne Elorza ◽  
Ibon Aranberri ◽  
Xiangming Zhou ◽  
Gediminas Kastiukas ◽  
Juan Antonio Alduncin

Background: Polyurethane (PU) foams contained in construction and demolition wastes (CDW) represent a great environmental impact, since they usually end in landfill or incineration processes. The goal of this work is to develop a way to formulate PU foams, maintaining (or ever improving) their performance, by the re-use of those industrial wastes. This procedure will allow minimize both the volume of disposal to be treated by other ways and the amount of pristine raw material needed to produce new PU foams. Methods: In this work, new rigid and soft polyurethane (PU) foams have been formulated with addition of recycled PU foams coming from demolition of buildings. Density, Fourier transform infrared analysis, compression properties and thermal conductivity were measured to characterize the resulting foams. Results: The work showed that addition of filler coming from recycled PU foams should be limited to low percentages, in order to allow good foam evolution from the reactants. Thermal conductivity values of modified rigid foams are worse than those of pristine foam, which is undesirable for thermal insulation purposes; however, in the case of soft foams, this parameter improved to some extent with low levels of recycled PU foam addition. Conclusions: The studied procedure could contribute to reduce the thermal conductivity of pristine soft PU foam, which would be of interest for applications where thermal insulation matters.


2014 ◽  
Vol 14 (4) ◽  
pp. 259-269 ◽  
Author(s):  
Mikelis Kirpluks ◽  
Ugis Cabulis ◽  
Viesturs Zeltins ◽  
Laura Stiebra ◽  
Andris Avots

Abstract One of the biggest disadvantages of rigid polyurethane (PU) foams is its low thermal resistance, high flammability and high smoke production. Greatest advantage of this thermal insulation material is its low thermal conductivity (λ), which at 18-28 mW/(m•K) is superior to other materials. To lower the flammability of PU foams, different flame retardants (FR) are used. Usually, industrially viable are halogenated liquid FRs but recent trends in EU regulations show that they are not desirable any more. Main concern is toxicity of smoke and health hazard form volatiles in PU foam materials. Development of intumescent passive fire protection for foam materials would answer problems with flammability without using halogenated FRs. It is possible to add expandable graphite (EG) into PU foam structure but this increases the thermal conductivity greatly. Thus, the main advantage of PU foam is lost. To decrease the flammability of PU foams, three different contents 3%; 9% and 15% of EG were added to PU foam formulation. Sample with 15% of EG increased λ of PU foam from 24.0 to 30.0 mW/(m•K). This paper describes the study where PU foam developed from renewable resources is protected with thermally expandable intumescent mat from Technical Fibre Products Ltd. (TFP) as an alternative to EG added into PU material. TFP produces range of mineral fibre mats with EG that produce passive fire barrier. Two type mats were used to develop sandwich-type PU foams. Also, synergy effect of non-halogenated FR, dimethyl propyl phosphate and EG was studied. Flammability of developed materials was assessed using Cone Calorimeter equipment. Density, thermal conductivity, compression strength and modulus of elasticity were tested for developed PU foams. PU foam morphology was assessed from scanning electron microscopy images.


2021 ◽  
pp. 0021955X2110626
Author(s):  
Tae Seok Kim ◽  
Yeongbeom Lee ◽  
Chul Hyun Hwang ◽  
Kwang Ho Song ◽  
Woo Nyon Kim

The effect of perfluoroalkane (PFA) on the morphology, thermal conductivity, mechanical properties and thermal stability of rigid polyurethane (PU) foams was investigated under ambient and cryogenic conditions. The PU foams were blown with hydrofluorolefin. Morphological results showed that the minimum cell size (153 μm) was observed when the PFA content was 1.0 part per hundred polyols by weight (php). This was due to the lower surface tension of the mixed polyol solution when the PFA content was 1.0 php. The thermal conductivity of PU foams measured under ambient (0.0215 W/mK) and cryogenic (0.0179 W/mK at −100°C) conditions reached a minimum when the PFA content was 1.0 php. The low value of thermal conductivity was a result of the small cell size of the foams. The above results suggest that PFA acted as a nucleating agent to enhanced the thermal insulation properties of PU foams. The compressive and shear strengths of the PU foams did not appreciably change with PFA content at either −170°C or 20°C. However, it shows that the mechanical strengths at −170°C and 20°C for the PU foams meet the specification. Coefficient of thermal expansion, and thermal shock tests of the PU foams showed enough thermal stability for the LNG carrier’s operation temperature. Therefore, it is suggested that the PU foams blown by HFO with the PFA addition can be used as a thermal insulation material for a conventional LNG carrier.


2020 ◽  
Vol 12 (12) ◽  
pp. 4841
Author(s):  
Maria Teresa Ferrandez-Garcia ◽  
Antonio Ferrandez-Garcia ◽  
Teresa Garcia-Ortuño ◽  
Clara Eugenia Ferrandez-Garcia ◽  
Manuel Ferrandez-Villena

The manufacture of technical materials of mineral and synthetic origin currently used for thermal insulation in buildings consumes a large amount of energy and they are not biodegradable. In order to reduce the environmental problems generated by their manufacture, an increasing amount of research is being carried out on the use of renewable and ecological resources. Consequently, the use of plant fibers and natural adhesives in the development of new thermal insulating products is increasing worldwide. Palm trees were used as a replacement for wood in some traditional constructions in places with scarce wood resources. This paper discusses the use of palm pruning waste in the manufacture of particleboards, using citric acid as a natural binder. Five particle sizes of Washingtonia palm rachis were used as the raw material for manufacturing the boards and the citric acid content was set at 10% by weight, in relation to the weight of the rachis particles. Single-layer agglomerated panels were made, applying a pressure of 2.6 MPa and a temperature of 150 °C for 7 min. Twenty panels were produced and their density, thickness swelling, water absorption, modulus of rupture, internal bonding strength and thermal conductivity properties were studied. Smaller particle size resulted in better mechanical properties. The boards had an average thermal conductivity of 0.084 W/m·K, meaning that these boards could be used for thermal insulation in buildings.


2011 ◽  
Vol 250-253 ◽  
pp. 502-506
Author(s):  
Jin Xiu Gao ◽  
Xiao Shan Wang ◽  
Lu Bao Li ◽  
Hua Ruan ◽  
Hao Chi Tu ◽  
...  

In recent years, many buildings went up in flames one after another. It is thought-provoking. So the fire-proof property should be considered into one of the most important performance of the building thermal insulation materials. As a result, the study on the expanded perlite lightweight porous inorganic material heated up fast although its application still has some problems to be solved. In this paper, we take the expanded perlite as raw material to make thermal insulation board, and then study on the effect of volume weight on the coefficient of thermal conductivity and tensile strength. What is more important, we find that a new binding agent of Na2O-B2O3-SiO2 syetem sol contributes to improving its water resistance.


2020 ◽  
Author(s):  
◽  
Aiga Ivdre

The Thesis aims to develop innovative polyols suitable for the production of rigid PU foam from recycled PET flakes and renewable raw material resources (rapeseed oil and tall oil) and to evaluate the effect of polyols on the most important properties of rigid PU foams as a thermal insulation material.


2017 ◽  
Vol 7 (1) ◽  
pp. 157-161 ◽  
Author(s):  
Пастори ◽  
Zoltan Pastori ◽  
Мохачине ◽  
Il'diko Mohachine ◽  
Горбачева ◽  
...  

The problem of industrial use of tree bark is relevant and has practical importance for complex processing of wood raw material. Barks are available in Hungary and Russia in large quantities, but they are not widely used for different purposes than producing energy. One of the perspective areas of utilization of tree bark is its use as raw material for the production of thermal insulation panels. The present study focuses on the thermal insulation capacity of tree bark. Thermal conductivity properties of two broadleaved (black locust (Robinia pseudoacacia), pannónia poplar (Populus euramericana cv. Pannónia)) and three coniferous (larch (Larix decidua), spruce (Picea abies) and scots pine (Pinus silvestris)) tree species were examined. Based on these results, the scopes of the tested species were further narrowed, while the best results showing black locust was used for pressed insulation panel. Three different fractions were produced made of grained black locust bark. Furthermore, the heat insulation capacities of bark were investigated by compressing the chipped bark particles until the lowest heat conductivity was reached. Results show a competitive thermal insulation property to the traditionally used insulation materials, the value was 0.0613 W/mK reached by black locust bark chips. The broadleaved tree bark chips have a lower thermal conductivity than coniferous species. By using fine, mid, and coarse fraction of black locust bark were produced and the difference of thermal conductivity between them was negligible. Although the fine fractionated black locust bark chip thermal conductivity was 0.042 W/mK.


1970 ◽  
Vol 17 (2) ◽  
pp. 208-212 ◽  
Author(s):  
Jolanta VĖJELIENĖ ◽  
Albinas GAILIUS ◽  
Sigitas VĖJELIS ◽  
Saulius VAITKUS ◽  
Giedrius BALČIŪNAS

The development of new thermal insulation materials needs to evaluate properties and structure of raw material, technological factors that make influence on the thermal conductivity of material. One of the most promising raw materials for production of insulation material is straw. The use of natural fibres in insulation is closely linked to the ecological building sector, where selection of materials is based on factors including recyclable, renewable raw materials and low resource production techniques In current work results of research on structure and thermal conductivity of renewable resources for production thermal insulating materials are presented. Due to the high abundance of renewable resources and a good its structure as raw material for thermal insulation materials barley straw, reeds, cattails and bent grass stalks are used. Macro- and micro structure analysis of these substances is performed. Straw bales of these materials are used for determining thermal conductivity. It was found that the macrostructure has the greatest effect on thermal conductivity of materials. Thermal conductivity of material is determined by the formation of a bale due to the large amount of pores among the stalks of the plant, inside the stalk and inside the stalk wall.http://dx.doi.org/10.5755/j01.ms.17.2.494


Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6385
Author(s):  
Baiba Gaujena ◽  
Vladislavs Agapovs ◽  
Anatolijs Borodinecs ◽  
Ksenia Strelets

Nowadays, sustainable construction is a key factor for reaching net-zero emissions of carbon dioxide all over the world. This goal is impossible to achieve by merely reducing the energy consumption of end-users. A more holistic approach should be taken, adopting sustainable industrial practices that use environmentally friendly materials on a large scale. This paper presents the analysis of the hydrothermal properties of hemp thermal insulation plates. We carried out extensive measurements and the analysis of the thermal conductivity coefficient, drying-out dynamics, and water absorption. The study was performed with experimental insulation samples based on the fiber obtained from hemp stems, prepared using different adhesive powders. The dimensions of the analyzed samples were 300 × 300 mm. The proposed samples are not yet available in mass production. Hemp does not flower in the Baltic region and was traditionally used for soil regeneration. Thus, using this raw material increases the added value of agricultural residues. Three series of hemp fiber samples with different substances and pressing modes were evaluated in the study. Each set of samples consisted of four plates with varying thicknesses and two different densities: 200 kg/m3 and 300 kg/m3. All samples exhibited a significant increase in moisture absorption and a strong correlation with the increase in thermal conductivity. The average thermal conductivity of the test samples ranged from 0.0544 to 0.0594 W/mK. The impact of the adhesive powder on the thermal conductivity was found to be extremely small. However, the values obtained were much higher than those for traditional thermal insulation materials, allowing to utilize the local agriculture residues and providing material for the construction of eco-friendly buildings.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Hongyu Fan ◽  
Ali Tekeei ◽  
Galen J. Suppes ◽  
Fu-Hung Hsieh

The effect of incorporating 1–7% microsphere and nanoclay fillers on the physical properties of polyurethane (PU) foams containing 15% soybean oil-based polyol was investigated. Increasing filler percentage reduced the PU foam density. The compressive strength of PU foams decreased slightly when increasing the microsphere content from 1 to 3% and then increased. At 7% microsphere content, the foams displayed the same compressive strength as the control foams made from 100% petroleum polyol. For PU foams reinforced with nanoclay, their compressive strength changed little from 1 to 5%, but decreased at 7% due to a lower density and weaker matrix structure. Foams containing 5 to 7% microspheres or 3 to 7% nanoclay had density-compressive strength comparable or superior to the control. Foams reinforced with fillers had more cells and smaller cell size than foams made from 15% soy-polyol but without fillers. During the foaming process, the maximal temperatures reached by PU foams were not affected by the presence of 1 to 7% of microspheres or nanoclay, but slightly lower than the control. In addition, foams with fillers displayed roughly the same thermal conductivity as soy-polyol based foams without fillers.


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