A Study of the Influence of Polymer and Cell Structure on Polyurethane Foam Properties for Better Riding Comfort

2020 ◽  
pp. 267-274
Author(s):  
Masahiro Isobe ◽  
Kazuto Usaka ◽  
Hiroyuki Utsumi ◽  
Kazuhiko Ohkubo
Keyword(s):  
Polyurethane Foam ◽  
Cell Structure ◽  
Foam Properties

Effect of Nano-and Micro-Silica Fillers on Polyurethane Foam Properties

2002 ◽  
Vol 38 (3) ◽  
pp. 229-239 ◽  
Author(s):  
I. Javni ◽  
W. Zhang ◽  
V. Karajkov ◽  
Z. S. Petrovic ◽  
V. Divjakovic
Keyword(s):  
Polyurethane Foam ◽  
Silica Fillers ◽  
Foam Properties ◽  
Micro Silica

scholarly journals Variation of Mechanical Characteristics of Polyurethane Foam: Effect of Test Method

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2672 ◽  
Author(s):  
Ki-Beom Park ◽  
Hee-Tae Kim ◽  
Nam-Yong Her ◽  
Jae-Myung Lee
Keyword(s):  
Polyurethane Foam ◽  
Evaluation Method ◽  
Mechanical Performance ◽  
Cell Structure ◽  
Extreme Environments ◽  
Evaluation Criteria ◽  
Test Method ◽  
Material Behavior ◽  
Insulation Material ◽  
Binding Effect

Polyurethane foam (PUF), a representative insulation material, not only prevents heat conduction but can also support a load. Particular interest in rigid PUF proliferated over the past several years in fields where extreme environments are applied. A closed-cell structure which forms the interior of rigid PUF serves to maximize the utilization of these polymeric foams. Rigid PUF is more sensitive to external conditions such as temperature or restraint than other structural materials such as steel. Depending on the market trends in which utilization of a cryogenic environment is expanding, the tendency of material behavior resulting from the binding effect also needs to be investigated. However, most conventional compression test method standards applicable to rigid PUF do not adequately reflect the restraints. Therefore, this study proposes a method for evaluating the mechanical performance of materials in a more reliable manner than that of conventional tests. Experimental observation and analysis validated this compression evaluation method in which constraints are considered. Consequently, the compressive strength of rigid PUF compared to the results of the conventional test showed a difference of up to 0.47 MPa (approximately 23%) at cryogenic temperatures. This result suggests that there are important factors to consider when assessing performance from a material perspective in an environment where rigid PUF insulation is utilized. It is believed that the test methods newly proposed in this study will provide an experimental framework that can be applied to the evaluation criteria of material properties and reflected in structural design.

scholarly journals Synthesis of a DOPO-triazine additive and its flame-retardant effect in rigid polyurethane foam

e-Polymers ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 235-243 ◽  
Author(s):  
Lin Liu ◽  
Rui Lv
Keyword(s):  
Flame Retardant ◽  
Polyurethane Foam ◽  
Cell Structure ◽  
Rigid Polyurethane Foam ◽  
Flame Resistance ◽  
Limiting Oxygen Index ◽  
Flame Retarded ◽  
Flame Retardant Properties ◽  
Mechanical Performances ◽  
Halogen Free

AbstractA DOPO (9,10-dihydro-9-oxa-10-phosphaphen-anthrene-10-oxide)-based halogen-free flame retardant (ODOPM-CYC) was synthesized and incorporated in rigid polyurethane foam (RPUF). The structure of ODOPM-CYC was characterized by Fourier transform infrared spectra (FTIR), 1H NMR and 31P NMR. The effects of ODOPM-CYC on the flame resistance, mechanical performances, thermal properties and cell structure of RPUF were also investigated. The results showed that the incorporation of ODOPM-CYC strikingly enhanced flame retardant properties of RPUF. The flame retarded RPUF acquired a limiting oxygen index (LOI) value of 26% and achieved UL-94 V-0 rating with the phosphorus content of 3 wt%. The smoke production rate (SPR) also showed an obvious decrease and total smoke release (TSR) was 39.8% lower than that of neat RPUF. Besides, the results demonstrated that the incorporation of ODOPM-CYC provided RPUF better thermal stability but did not show any obvious influence on its thermal conductivity.

scholarly journals Investigation of the Foam Development Stages by Non-Destructive Testing Technology Using the Freeze Foaming Process

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2478
Author(s):  
Johanna Maier ◽  
Thomas Behnisch ◽  
Vinzenz Geske ◽  
Matthias Ahlhelm ◽  
David Werner ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Cell Structure ◽  
Destructive Testing ◽  
Foaming Process ◽  
Artificial Bones ◽  
Testing Technology ◽  
Foam Properties ◽  
Lightweight Engineering ◽  
Cellular Components ◽  
First Time

With a novel Freeze Foaming method, it is possible to manufacture porous cellular components whose structure and composition also enables them for application as artificial bones, among others. To tune the foam properties to our needs, we have to understand the principles of the foaming process and how the relevant process parameters and the foam’s structure are linked. Using in situ analysis methods, like X-ray microcomputed tomography (µCT), the foam structure and its development can be observed and correlated to its properties. For this purpose, a device was designed at the Institute of Lightweight Engineering and Polymer Technology (ILK). Due to varying suspension temperature and the rate of pressure decrease it was possible to analyze the foam’s developmental stages for the first time. After successfully identifying the mechanism of foam creation and cell structure formation, process routes for tailored foams can be developed in future.

scholarly journals Bio-Based Rigid Polyurethane Foam Composites Reinforced with Bleached Curauá Fiber

2021 ◽  
Vol 22 (20) ◽  
pp. 11203
Author(s):  
Sylwia Członka ◽  
Eduardo Fischer Kerche ◽  
Roberta Motta Neves ◽  
Anna Strąkowska ◽  
Krzysztof Strzelec
Keyword(s):  
Mechanical Properties ◽  
Polyurethane Foam ◽  
Cellular Structure ◽  
Cell Structure ◽  
Rigid Polyurethane Foam ◽  
Processing Times ◽  
Civil Aircraft ◽  
Viscoelastic Characteristics ◽  
Vegetable Fiber ◽  
Curauá Fiber

This study aims to evaluate the influence of using a bleached Curauá fiber (CF) as filler in a novel rigid polyurethane foam (RPUF) composite. The influence of 0.1, 0.5 and 1 wt.% of the reinforcements on the processing characteristics, cellular structure, mechanical, dynamic-mechanical, thermal, and flame behaviors were assessed and discussed for RPUF freely expanded. The results showed that the use of 0.5 wt.% of CF resulted in RPUF with smoother cell structure with low differences on the processing times and viscosity for the filled pre-polyol. These morphological features were responsible for the gains in mechanical properties, in both parallel and perpendicular rise directions, and better viscoelastic characteristics. Despite the gains, higher thermal conductivity and lower flammability were reported for the developed RPUF composites, related to the high content of cellulose and hemicellulose on the bleached CF chemical composition. This work shows the possibility of using a Brazilian vegetable fiber, with low exploration for the manufacturing of composite materials with improved properties. The developed RPUF presents high applicability as enhanced cores for the manufacturing of structural sandwich panels, mainly used in civil, aircraft, and marine industries.

scholarly journals Application of Walnut Shells-Derived Biopolyol in the Synthesis of Rigid Polyurethane Foams

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2687 ◽  
Author(s):  
Sylwia Członka ◽  
Anna Strąkowska ◽  
Agnė Kairytė
Keyword(s):  
Thermal Conductivity ◽  
Mechanical Characteristics ◽  
Cell Structure ◽  
Weight Ratio ◽  
Polyurethane Foams ◽  
Maximum Temperature ◽  
Walnut Shells ◽  
Foam Properties ◽  
The Fourier Transform ◽  
The Impact

This study aimed to examine rigid polyurethane (PUR) foam properties that were synthesized from walnut shells (WS)-based polyol. The Fourier Transform Infrared Spectroscopy (FTIR) results revealed that the liquefaction of walnut shells was successfully performed. The three types of polyurethane (PUR) foams were synthesized by replacement of 10, 20, and 30 wt% of a petrochemical polyol with WS-based polyol. The impact of WS-based polyol on the cellular morphology, mechanical, thermal, and insulating characteristics of PUR foams was examined. The produced PUR foams had apparent densities from 37 to 39 kg m−3, depending on the weight ratio of WS-based polyol. PUR foams that were obtained from WS-based polyol exhibited improved mechanical characteristics when compared with PUR foams that were derived from the petrochemical polyol. PUR foams produced from WS-based polyol showed compressive strength from 255 to 310 kPa, flexural strength from 420 to 458 kPa, and impact strength from 340 to 368 kPa. The foams that were produced from WS-based polyol exhibited less uniform cell structure than foams derived from the petrochemical polyol. The thermal conductivity of the PUR foams ranged between 0.026 and 0.032 W m−1K−1, depending on the concentration of WS-based polyol. The addition of WS-based polyol had no significant influence on the thermal degradation characteristics of PUR foams. The maximum temperature of thermal decomposition was observed for PUR foams with the highest loading of WS-based polyol.

Polyol from spent coffee grounds: Performance in a model pour-in-place rigid polyurethane foam system

2020 ◽  
Vol 56 (6) ◽  
pp. 630-645 ◽  
Author(s):  
Ibrahim Sendijarevic ◽  
Karol W Pietrzyk ◽  
Christi M. Schiffman ◽  
Vahid Sendijarevic ◽  
Alper Kiziltas ◽  
...  
Keyword(s):  
Polyurethane Foam ◽  
Raw Materials ◽  
Intact Cell ◽  
Cell Structure ◽  
Acid Value ◽  
Polyurethane Foams ◽  
Rigid Polyurethane Foam ◽  
Spent Coffee Grounds ◽  
Rigid Polyurethane Foams ◽  
Coffee Grounds

The objective of this study was to produce a polyol from spent coffee grounds via acid liquification process that meets performance requirements for use in polyurethane applications. The spent coffee grounds based polyol was characterized and evaluated on a fully catalyzed model rigid polyurethane foam system. The pH of the polyol was 6.8, acid value 4.12 mg KOH/g, and hydroxyl value 302.6 mg KOH/g, which are in the range of polyols used in rigid polyurethane foams. The reactivity study confirmed enhanced reactivity of the spent coffee grounds polyol compared to standard sucrose-glycerol initiated polyether polyols, which can be attributed to higher content of primary reactive hydroxyls. Scanning electron microscopy microphotographs of the foams prepared with 10%, 20%, and 30% spent coffee grounds polyol based on total polyols in the formulation revealed a drained dodecahedron type cell structure with intact cell windows as a clear indication of the closed cell structure typical for the rigid polyurethane foams used in thermal insulation applications. Results of this study confirmed the feasibility to produce polyols from spent coffee grounds with performance characteristics suitable for polyurethane application. The fact that spent coffee grounds are readily available industrial waste generated in instant coffee manufacturing, makes this biomass residue a sustainable source of raw materials for scalable production of polyols for polyurethanes.

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