Impact of blowing agent-blends on polyurethane foams thermal and mechanical properties

2020 ◽  
Author(s):  
Harith H. Al-Moameri ◽  
Baydaa Jaber Nabhan ◽  
Tawfeeq Wasmi M. ◽  
Mohammed Ali Abdulrehman
Keyword(s):  
Mechanical Properties ◽  
Polyurethane Foams ◽  
Thermal And Mechanical Properties ◽  
Blowing Agent

scholarly journals Vegetable Tannin as a Sustainable UV Stabilizer for Polyurethane Foams

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 480 ◽  
Author(s):  
Maria Oliviero ◽  
Mariamelia Stanzione ◽  
Marco D’Auria ◽  
Luigi Sorrentino ◽  
Salvatore Iannace ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Uv Radiation ◽  
Polyurethane Foams ◽  
Accelerated Weathering ◽  
Polyphenolic Compound ◽  
Uv Treatment ◽  
Blowing Agent ◽  
Performance Change ◽  
Urethane Linkage ◽  
Vegetable Tannin

A vegetable tannin, a flavonoid-type natural polyphenolic compound, was used to promote the stabilization of polyurethane foams against UV radiation. Several polyurethane foams were synthesized by using an isocyanate, and a mixture of ethoxylated cocoalkyl amine and vegetable tannin. The content of vegetable tannin was varied from 0 to 40 wt %. The effects of tannin and water (used as a blowing agent) on the foaming kinetics and cellular morphology of foams were investigated. Samples were subjected to accelerated weathering under UV radiation for 3 to 24 h, and FTIR and DMA analyses were conducted to assess the performance change. The former analysis revealed a strong inhibiting effect of tannin on urethane linkage degradation during the UV treatment. The mechanical properties were significantly affected by the addition of tannin. The capability of the foams to withstand UV radiation was dependent on the amount of tannin. At tannin contents higher than 20%, the decrease in mechanical properties under UV irradiation was almost avoided.

scholarly journals Hybrid Fly Ash-Based Geopolymeric Foams: Microstructural, Thermal and Mechanical Properties

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2919 ◽  
Author(s):  
Giuseppina Roviello ◽  
Laura Ricciotti ◽  
Antonio Jacopo Molino ◽  
Costantino Menna ◽  
Claudio Ferone ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Circular Economy ◽  
Coal Fly Ash ◽  
Silicate Solution ◽  
Thermal And Mechanical Properties ◽  
Blowing Agent ◽  
Materials Used

This research investigates the preparation and characterization of new organic–inorganic geopolymeric foams obtained by simultaneously reacting coal fly ash and an alkali silicate solution with polysiloxane oligomers. Foaming was realized in situ using Si0 as a blowing agent. Samples with density ranging from 0.3 to 0.7 g/cm3 that show good mechanical properties (with compressive strength up to ≈5 MPa for a density of 0.7 g/cm3) along with thermal performances (λ = 0.145 ± 0.001 W/m·K for the foamed sample with density 0.330 g/cm3) comparable to commercial lightweight materials used in the field of thermal insulation were prepared. Since these foams were obtained by valorizing waste byproducts, they could be considered as low environmental impact materials and, hence, with promising perspectives towards the circular economy.

Improvement of thermal and mechanical properties by control of formulations in rigid polyurethane foams from polyols functionalized with graphene oxide

2019 ◽  
Vol 136 (19) ◽  
pp. 47474 ◽  
Author(s):  
Mercedes Santiago‐Calvo ◽  
Victoria Blasco ◽  
Carolina Ruiz ◽  
Rodrigo París ◽  
Fernando Villafañe ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Polyurethane Foams ◽  
Thermal And Mechanical Properties ◽  
Rigid Polyurethane Foams

Structural, thermal, and mechanical properties of polyurethane foams prepared with starch as the main component of polyols

2007 ◽  
Vol 8 (2) ◽  
pp. 155-162 ◽  
Author(s):  
Dae-Hyun Kim ◽  
Oh-Jin Kwon ◽  
Seong-Ryul Yang ◽  
Jong-Shin Park ◽  
Byoung Chul Chun
Keyword(s):  
Mechanical Properties ◽  
Polyurethane Foams ◽  
Thermal And Mechanical Properties ◽  
Main Component

scholarly journals Chemically Functionalized Cellulose Nanocrystals as Reactive Filler in Bio-Based Polyurethane Foams

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2556
Author(s):  
Francesca Coccia ◽  
Liudmyla Gryshchuk ◽  
Pierluigi Moimare ◽  
Ferdinando de Luca Bossa ◽  
Chiara Santillo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cellulose Nanocrystals ◽  
Aqueous Media ◽  
Polyurethane Foams ◽  
Coupling Agents ◽  
Ftir Analysis ◽  
Thermal And Mechanical Properties ◽  
Efficient Coupling ◽  
Flexible Polyurethane ◽  
Pu Foams

Cellulose Nanocrystals, CNC, opportunely functionalized are proposed as reactive fillers in bio-based flexible polyurethane foams to improve, mainly, their mechanical properties. To overcome the cellulose hydrophilicity, CNC was functionalized on its surface by linking covalently a suitable bio-based polyol to obtain a grafted-CNC. The polyols grafted with CNC will react with the isocyanate in the preparation of the polyurethane foams. An attractive way to introduce functionalities on cellulose surfaces in aqueous media is silane chemistry by using functional trialkoxy silanes, X-Si (OR)3. Here, we report the synthesis of CNC-grafted-biopolyol to be used as a successful reactive filler in bio-based polyurethane foams, PUFs. The alkyl silanes were used as efficient coupling agents for the grafting of CNC and bio-polyols. Four strategies to obtain CNC-grafted-polyol were fine-tuned to use CNC as an active filler in PUFs. The effective grafting of the bio polyol on CNC was evaluated by FTIR analysis, and the amount of grafted polyol by thermogravimetric analysis. Finally, the morphological, thermal and mechanical properties and hydrophobicity of filled PUFs were thoughtfully assessed as well as the structure of the foams and, in particular, of the edges and walls of the cell foams by means of the Gibson–Ashby model. Improved thermal stability and mechanical properties of PU foams containing CNC-functionalized-polyol are observed. The morphology of the PU foams is also influenced by the functionalization of the CNC.

The effects of functional nanofillers on the reaction kinetics, microstructure, thermal and mechanical properties of water blown rigid polyurethane foams

Polymer ◽  
2018 ◽  
Vol 150 ◽  
pp. 138-149 ◽  
Author(s):  
Mercedes Santiago-Calvo ◽  
Josías Tirado-Mediavilla ◽  
José Luis Ruiz-Herrero ◽  
Miguel Ángel Rodríguez-Pérez ◽  
Fernando Villafañe
Keyword(s):  
Mechanical Properties ◽  
Reaction Kinetics ◽  
Polyurethane Foams ◽  
Thermal And Mechanical Properties ◽  
Rigid Polyurethane Foams
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