Study on the Aging Rules of Rigid Polyurethane Foams at Indoor Storage and Different Hygrothermal Conditions

The aging rules of rigid polyurethane foam (PUR) at indoor storage and different hygrothermal conditions have been studied. Four parameters, which are mass, dimension, compressive strength and compressive modulus were tested. At indoor storage, mass, dimension and compressive strength vary slowly with an increase in aging time, while compressive modulus decreases quickly. PUR is sensitive to relative humidity (RH) verified by accelerated hygrothermal aging, and hydrolysis of ester group is the main reason resulting in the decrease of compressive properties. The filling with fire retardant and glass beads had some effect on hygrothermal aging properties of PUR. The addition of fire retardant increased compressive strength with aging time in the total trend, but it made dimension stability worse. The addition of glass beads slightly improved hygrothermal aging properties.

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Chlorine-Functional Silsesquioxanes (POSS-Cl) as Effective Flame Retardants and Reinforcing Additives for Rigid Polyurethane Foams

Molecules ◽

10.3390/molecules26133979 ◽

2021 ◽

Vol 26 (13) ◽

pp. 3979

Author(s):

Anna Strąkowska ◽

Sylwia Członka ◽

Karolina Miedzińska ◽

Krzysztof Strzelec

Keyword(s):

Flame Retardants ◽

Elevated Temperatures ◽

Bending Strength ◽

Reaction System ◽

Fire Retardant ◽

Polyurethane Foams ◽

Polymerization Reaction ◽

Three Point Bending ◽

One Step

The subject of the research was the production of silsesquioxane modified rigid polyurethane (PUR) foams (POSS-Cl) with chlorine functional groups (chlorobenzyl, chloropropyl, chlorobenzylethyl) characterized by reduced flammability. The foams were prepared in a one-step additive polymerization reaction of isocyanates with polyols, and the POSS modifier was added to the reaction system in an amount of 2 wt.% polyol. The influence of POSS was analyzed by performing a series of tests, such as determination of the kinetics of foam growth, determination of apparent density, and structure analysis. Compressive strength, three-point bending strength, hardness, and shape stability at reduced and elevated temperatures were tested, and the hydrophobicity of the surface was determined. The most important measurement was the determination of the thermal stability (TGA) and the flammability of the modified systems using a cone calorimeter. The obtained results, after comparing with the results for unmodified foam, showed a large influence of POSS modifiers on the functional properties, especially thermal and fire-retardant, of the obtained PUR-POSS-Cl systems.

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Experimental Study on Improvement of Marine Soft Soil with Alkali Residue

E3S Web of Conferences ◽

10.1051/e3sconf/20185304021 ◽

2018 ◽

Vol 53 ◽

pp. 04021

Author(s):

SHAO Yong ◽

LIU Xiao-li ◽

ZHU Jin-jun

Keyword(s):

Experimental Study ◽

Compressive Strength ◽

Unconfined Compressive Strength ◽

Void Ratio ◽

Soft Soil ◽

Compressive Modulus ◽

Engineering Properties ◽

Test Results ◽

Use Of Resources ◽

One Year

Industrial alkali slag is the discharge waste in the process of alkali production. About one million tons of alkali slag is discharged in China in one year. It is a burden on the environment, whether it is directly stacked or discharged into the sea. If we can realize the use of resources, it is a multi-pronged move, so alkali slag is used to improve solidified marine soft soil in this paper. The test results show that the alkali residue can effectively improve the engineering properties of marine soft soil. Among them, the unconfined compressive strength and compressive modulus are increased by about 10 times, and the void ratio and plasticity index can all reach the level of general clay. It shows that alkali slag has the potential to improve marine soft soil and can be popularized in engineering.

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Preparation of rigid polyurethane foams using low-emission catalysts derived from metal acetates and ethanolamine

e-Polymers ◽

10.1515/epoly-2016-0021 ◽

2016 ◽

Vol 16 (4) ◽

pp. 265-275 ◽

Cited By ~ 5

Author(s):

Duangruthai Sridaeng ◽

Wannisa Jitaree ◽

Preecha Thiampanya ◽

Nuanphun Chantarasiri

Keyword(s):

Compressive Strength ◽

Catalytic Activity ◽

Rise Time ◽

Polyurethane Foams ◽

Gel Time ◽

Commercial Catalyst ◽

Metal Acetate ◽

Viscous Liquids ◽

Low Emission ◽

Cu And Zn

AbstractTwo metal acetate-ethanolamine complexes, namely Cu(OAc)2(EA) and Zn(OAc)2(EA), were synthesized from metal acetates [M(OAc)2, where M=Cu and Zn] and ethanolamine (EA). These metal acetate-ethanolamine complexes can be used as catalysts in the preparation of rigid polyurethane (RPUR) foams. Both Cu(OAc)2(EA) and Zn(OAc)2(EA) were obtained as viscous liquids, which have very weak odor and could be easily dissolved in the starting materials of RPUR foam formulation. The results were compared with RPUR foam prepared from dimethylcyclohexylamine (DMCHA), which is a commercial catalyst with very strong amine odor. Considering the gel time and rise time, Cu(OAc)2(EA) had higher catalytic activity than Zn(OAc)2(EA) and both metal acetate-ethanolamine complexes had lower catalytic activity than DMCHA. Density and compressive strength of RPUR foam catalyzed by Cu(OAc)2(EA) were comparable to that prepared from DMCHA.

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Development of Water Blown Bio-Based Thermoplastic Polyurethane Foams

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.584.361 ◽

2012 ◽

Vol 584 ◽

pp. 361-365 ◽

Cited By ~ 1

Author(s):

Baralu Jagannatha Rashmi ◽

Daniela Rusu ◽

Kalappa Prashantha ◽

Marie France Lacrampe ◽

Patricia Krawczak

Keyword(s):

Compressive Strength ◽

Cell Size ◽

Surfactant Concentration ◽

Thermoplastic Polyurethane ◽

Polyurethane Foams ◽

Chain Extender ◽

Morphological Properties ◽

Foam Sample ◽

Glass Transition Temperatures ◽

Blowing Agent

Water blown biobased thermoplastic polyurethane (TPU) foams were prepared using synthetic and biobased chain extender. The concentration of chain extender, blowing agent (BA) and surfactant were varied and their effects on physical, mechanical and morphological properties of foams were investigated. Density, compressive strength and modulus of foams decreases with an increase in BA content and increased with chain extender concentration, but do not change significantly with change in surfactant concentration. The glass-transition temperatures of the foam samples increases with an increase in BA and chain extender concentration. The cell size of the foam sample increases slightly with an increase in BA whereas chain extender concentration has no effect on cell size.

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Effect of micro in-plane fiber waviness on compressive properties of unidirectional fabric composites

Journal of Composite Materials ◽

10.1177/0021998317740197 ◽

2017 ◽

Vol 52 (15) ◽

pp. 2065-2074 ◽

Cited By ~ 3

Author(s):

Bo Wang ◽

Nobuhide Uda ◽

Kousei Ono ◽

Hiroto Nagai

Keyword(s):

Compressive Strength ◽

Numerical Model ◽

Tensile Stress ◽

Compressive Modulus ◽

Two Dimensional ◽

Compressive Properties ◽

Fiber Waviness ◽

Experimental Part ◽

Fabric Composites ◽

Vartm Process

In this paper, a combination of experimentation and analysis is used to study the effect of micro in-plane fiber waviness on the compressive properties of unidirectional fabric composites. The experimental part includes a measurement of the micro in-plane fiber waviness in two types of unidirectional fabrics, manufacturing composites with each unidirectional fabric via VaRTM process and tests for establishing the compressive modulus and strengths of the composites. The compressive strengths were confirmed to be affected by the micro in-plane fiber waviness, but the compressive modulus was not. Furthermore, a two-dimensional numerical model is proposed to explain our experimental results. The numerical results indicate that the tensile stress (owing to the micro in-plane fiber waviness) and compressive stress along the weft and warp directions, respectively, of the composite lead to reductions in the compressive strength.

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Bio-based rigid polyurethane foam prepared from apricot stone shell-based polyol for thermal insulation application – Part 2: Morphological, mechanical, and thermal properties

BioResources ◽

10.15376/biores.15.3.6080-6094 ◽

2020 ◽

Vol 15 (3) ◽

pp. 6080-6094

Author(s):

Muhammed Said Fidan ◽

Murat Ertaş

Keyword(s):

Thermal Conductivity ◽

Compressive Strength ◽

Thermal Properties ◽

Thermogravimetric Analysis ◽

Polyurethane Foam ◽

Flame Retardants ◽

Compressive Modulus ◽

Cell Diameter ◽

Mechanical And Thermal Properties ◽

Rigid Polyurethane Foam

The procedure for the liquefaction of apricot stone shells was reported in Part 1. Part 2 of this work determines the morphological, mechanical, and thermal properties of the bio-based rigid polyurethane foam composites (RPUFc). In this study, the thermal conductivity, compressive strength, compressive modulus, thermogravimetric analysis, flammability tests (horizontal burning and limited oxygen index (LOI)) in the flame retardants), and scanning electron microscope (SEM) (cell diameter in the SEM) tests of the RPUFc were performed and compared with control samples. The results showed the thermal conductivity (0.0342 to 0.0362 mW/mK), compressive strength (10.5 to 14.9 kPa), compressive modulus (179.9 to 180.3 kPa), decomposition and residue in the thermogravimetric analysis (230 to 491 °C, 15.31 to 21.61%), UL-94 and LOI in the flame retardants (539.5 to 591.1 mm/min, 17.8 to 18.5%), and cell diameter in the SEM (50.6 to 347.5 μm) of RPUFc attained from liquefied biomass. The results were similar to those of foams obtained from industrial RPUFs, and demonstrated that bio-based RPUFc obtained from liquefied apricot stone shells could be used as a reinforcement filler in the preparation of RPUFs, specifically in construction and insulation materials. Moreover, liquefied apricot stone shell products have potential to be fabricated into rigid polyurethane foam composites.

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Preparation of rigid polyurethane foams with powder filler

Journal of Polymer Engineering ◽

10.1515/polyeng-2011-0108 ◽

2012 ◽

Vol 32 (2) ◽

Cited By ~ 3

Author(s):

Joanna Paciorek-Sadowska ◽

Bogusław Czupryński ◽

Joanna Liszkowska ◽

Kazimierz Piszczek

Keyword(s):

Compressive Strength ◽

Polyvinyl Chloride ◽

Softening Point ◽

Processing Parameters ◽

Polyurethane Foams ◽

Favorable Effect ◽

Start Time ◽

Rigid Polyurethane Foams ◽

Powder Filler ◽

Foam Plastics

Abstract The diversified properties of polyurethane (PUR) foam plastics result from differences in the receipts applied during their preparation. The preparation of rigid polyurethane-polyisocyanurate foams (PUR-PIR) with application of different amounts of polyvinyl chloride (PVC) s-70 as a filler is described in this study. It was found that application of PVC s-70 has an effect on the prolongation of processing parameters, i.e., start time and, to a greater extent, expansion and gelation times. Moreover, it was found that introduction of filler into the foam composition causes a reduction in the capacity of the foam to absorb water; however, a distinct change in the amount of closed cells in comparison with standard foam was not observed. A favorable effect of filler on brittleness and flammability of PUR-PIR foams (significant reduction) as well as on compressive strength and softening point (a significant increase in these values) was observed.

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Compression Characterization of Polyurethane Foams with Different Formulations of Polyol and MDI

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.815.74 ◽

2015 ◽

Vol 815 ◽

pp. 74-78

Author(s):

Sinar Arzuria Adnan ◽

Firuz Zainuddin ◽

Hazizan Md. Akil ◽

Sahrim Hj Ahmad

Keyword(s):

Compressive Strength ◽

Energy Absorption ◽

Palm Oil ◽

Polyurethane Foams ◽

Methylene Diphenyl Diisocyanate ◽

Pu Foams

Rigid polyurethane (PU) foams were prepared with palm oil based polyols (POP) and methylene diphenyl diisocyanate (MDI) in order to archieve rigid formulations. The effect of the different amount of MDI (1 wt.%, 1.1 wt.% and 2 wt.%) were studied in density, compressive strength and energy absorption. It was found that the higher compressive strength of the PU foams showed at 1.604 MPa whereas the amount of MDI increased to 1.1 wt. %. The increased amount of MDI to 2 wt.% showed the higher value in density (0.0531 kg/m3) and energy absorption with 46.490 J for 70 % displacement.

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Preparation of open cell rigid polyurethane foams and modified with organo-kaolin

Journal of Cellular Plastics ◽

10.1177/0021955x19880507 ◽

2019 ◽

Vol 56 (4) ◽

pp. 435-447

Author(s):

Guojian Wang ◽

Tao Yang

Keyword(s):

Compressive Strength ◽

Polyurethane Foam ◽

Coupling Agent ◽

Silane Coupling Agent ◽

Polyurethane Foams ◽

Compressive Property ◽

Rigid Polyurethane Foam ◽

Open Cell ◽

Silane Coupling ◽

Cell Opening

The open cell rigid polyurethane foam (ORPUF) was prepared by adding chemical cell openers including O-500 and AK-9903. The FTIR results of cell openers and open cell rate of ORPUFs showed that O-500 has more effective cell opening capacity. In the ORPUF foaming formulation using O-500 as cell opener, silane coupling agent (KH-550) modified kaolin (organo-kaolin) was introduced into ORPUF with different weight loadings. The cellular morphology, apparent density, and compressive strength of the foams were tested in order to investigate the effects of organo-kaolin on the open cell rate and compressive property of the foams. The results showed that the open cell rate of ORPUFs slightly increased from 83.9% to 92.9% with the content of organo-kaolin. Meanwhile, compared to neat ORPUF, the compressive strength of foams increased by 72.8% when the content of introduced organo-kaolin was 4 parts per hundred of polyol by mass (php).

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