The Effects of Henna Fillers on the Properties of Polyurethane Foam Composites

2020 ◽  
Vol 1010 ◽  
pp. 520-525
Author(s):  
Sinar Arzuria Adnan ◽  
Firuz Zainuddin ◽  
Nur Hidayah Ahmad Zaidi ◽  
Nur Afikah Zulkeply ◽  
Nur Maizatul Shima Adzali ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Cell Wall ◽  
Water Absorption ◽  
Cell Structure ◽  
Natural Fibers ◽  
Diphenylmethane Diisocyanate ◽  
Core Density ◽  
Blowing Agent ◽  
Pu Foam ◽  
Absorption Percentage

Polyurethane (PU) foam were produced from polyol (PolyGreen R3110) and 4,4- diphenylmethane diisocyanate (Maskiminate 80) with distilled water as a blowing agent. Natural fibers have received more attention from researchers due to their ability to increase the properties of the polymer composites. In this work, PU/Henna foam composites were prepared by used Henna fibers at different loading of 5, 10, 15 and 20 wt. %. The effect of different Henna loading on PU foam were investigated by density, compression test, morphology and water absorption. Core density of PU/Henna foam composites increased with addition Henna compared to control PU and showed highest core density of 85.10 kgm-3. Compressive strength decreased to 0.53 MPa after Henna addition at 5 % PU/Henna foam composites. Henna addition to 20 % PU/Henna foam composites were reduced the compressive strength to 0.97 MPa due to stiffness effect of Henna that contributed to embrittlement of the cell wall. The distorted cell wall and less uniform of cell structure were proved by SEM due to Henna addition as compared to control PU. Water absorption percentage of PU/Henna foam composites were increased with Henna addition as compared to control PU. It is because hydrophilic properties of Henna tendency to absorb moisture.

Microscopical, physico-chemical, mineralogical, and mechanical characterization of Sansevieria zeylanica fibers as potential reinforcement of composite structures

2016 ◽  
Vol 51 (6) ◽  
pp. 811-829 ◽  
Author(s):  
P Ponnu Krishnan ◽  
J Selwin Rajadurai
Keyword(s):  
Cell Wall ◽  
Thermogravimetric Analysis ◽  
Composite Structures ◽  
Cell Structure ◽  
Natural Fibers ◽  
Crystallinity Index ◽  
Primary Cell Wall ◽  
Mechanical And Thermal Properties ◽  
Fiber Density ◽  
Cellulose Component

The aim of this article is to examine for the first time the morphological, physical, chemical, mechanical, and thermal properties of a new kind of fibers, extracted from the leaves of a plant of the Asparagaceae family, to make it possible to use them as potential reinforcement for composite structures. The fibers were extracted from the leaves of Sansevieria zeylanica by decortication process. The presence of mechanical fibers and ribbon fibers were identified through the anatomy of Sansevieria zeylanica leaves. The hierarchical cell structure of these fibers was analyzed through polarized optical microscopy and scanning electron microscopy. It consists of primary cell wall, secondary cell wall, fiber lumen, and middle lamellae. The chemical composition of the natural fibers, in terms of cellulose 76.12%, hemicelluloses 9.32%, lignin 4.28%, and ash content 1.36%, was analyzed by using standard test methods and compared with other natural fibers. The fiber density and fineness were found to be 0.945 ± 0.004 g/cm3 and 8.35 tex, respectively. The thermal behavior of the fiber was investigated through thermogravimetric analysis/differential thermogravimetric analysis. The initial degradation temperature of the cellulose component is 304℃. The results obtained through Fourier transform infrared spectroscopy and X-ray diffraction showed the presence of cellulose with the crystallinity index of 66.67%. Finally, single fiber tensile tests have been performed to assess the mechanical properties. Tensile test of Sansevieria zeylanica fibers showed the tensile strength of 359 MPa and Youngs modulus of 8 GPa.

scholarly journals The Use of Waste from the Production of Rapeseed Oil for Obtaining of New Polyurethane Composites

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1431 ◽  
Author(s):  
Joanna Paciorek-Sadowska ◽  
Marcin Borowicz ◽  
Marek Isbrandt ◽  
Bogusław Czupryński ◽  
Łukasz Apiecionek
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Water Absorption ◽  
Apparent Density ◽  
Cell Structure ◽  
Dielectric Polarization ◽  
Cross Sectional ◽  
Rapeseed Cake ◽  
Foaming Process ◽  
Lower Reactivity

This article presents the results of research on obtaining new polyurethane materials modified by a by-product from vegetable oils industry—rapeseed cake. The chemical composition of rapeseed cake was examined. Rigid polyurethane-polyisocyanurate (RPU/PIR) foams containing a milled rapeseed cake in their composition were obtained as part of the conducted research. Biofiller was added in amount of 30 wt.% up to 60 wt.%. Effects of rapeseed cake on the foaming process, cell structure and selected properties of foams, such as apparent density, compressive strength, brittleness, flammability, absorbability, water absorption, thermal resistance and thermal conductivity are described. The foaming process of RPU/PIR foams modified by rapeseed cake was characterized by a lower reactivity, lower foaming temperature and decrease in dielectric polarization. This resulted in a slowed formation of the polyurethane matrix. Apparent density of RPU/PIR foams with biofiller was higher than in unmodified foam. Addition of rapeseed cake did not have a significant influence on the thermal conductivity of obtained materials. However, we observed a tendency for opening the cells of modified foams and obtaining a smaller cross-sectional area of cells. This led to an increase of absorbability and water absorption of obtained materials. However, an advantageous effect of using rapeseed cake in polyurethane formulations was noted. Modified RPU/PIR foams had higher compressive strength, lower brittleness and lower flammability than reference foam.

Synthesis of Palm Oil Based Polyol via Glycerolysis and Transamidation Reactions for Polyurethane Foam Production

2015 ◽  
Vol 735 ◽  
pp. 226-229 ◽  
Author(s):  
Khairul Azhar Abdul Halim ◽  
Sabrina Soloi ◽  
Rohah A. Majid
Keyword(s):  
Vegetable Oil ◽  
Palm Oil ◽  
Environmental Issue ◽  
Hydroxyl Group ◽  
Polypropylene Glycol ◽  
Diphenylmethane Diisocyanate ◽  
Blowing Agent ◽  
Pu Foam ◽  
Polymeric Resins ◽  
Foam Production

s. Renewable sources like vegetable oil have been used to prepare many polymeric resins due to the awareness on environmental issue and depletion on petrochemical sources. In polyurethane (PU) production, petroleum based polyol such as polypropylene glycol (PPG) has been replaced with plant based polyol from canola oil, soybean oil and palm oil. However, prior to be used, these vegetable oil needs to be modify chemically or physically in order to increase their functionality. In this study, palm oil (PO) has been modify via glyceroylsis and transamidation before reacted with diphenylmethane diisocyanate (MDI) at 1:1 NCO:OH ratio in the presence of distilled water as blowing agent and silicone surfactant as foam stabilizer to produce palm oil based PU foam. FTIR study of polyol from both routes shows that main hydroxyl group (-OH) have been successfully introduced into palm oil molecular structure. It was also found that the hardness of two routes have nearly similar values which were shore D 33.6 and 35.4 respectively. Both foams have potential to be used in many non-load bearing applications such as insulator in building or electrical appliances.

Reduction In Young's Modulus Of Aluminum Foams Due To Cell Wall Curvature And Corrugation

1998 ◽  
Vol 521 ◽  
Author(s):  
W. Sanders ◽  
L. J. Gibson
Keyword(s):  
Compressive Strength ◽  
Cell Wall ◽  
Young’S Modulus ◽  
Cell Walls ◽  
Young's Modulus ◽  
Cell Structure ◽  
Microstructural Characterization ◽  
Aluminum Foams ◽  
Element Analysis ◽  
Simple Bounds

ABSTRACTMeasurements of the Young's modulus and compressive strength of several closedcell aluminum foams indicate that they are lower than expected from models for foam behaviour. Microstructural characterization has revealed that there are a number of defects in the cell structure which may contribute to the reduction in mechanical properties. These include: cell wall curvature, cell wall corrugations, density variations and non-equiaxed cell shape. Finite element analysis of a closed-cell tetrakaidecahedral unit cell with idealized curved or corrugated cell walls indicates that these two types of defects can reduce the Young's modulus and compressive strength by up to 70%. In this paper we report the results of measurements of the curvature of the cell walls and of the amplitude and frequency of corrugations in the cell walls and use simple bounds to estimate the reduction in modulus that they are responsible for.

scholarly journals Castor Oil-Based Polyurethane Resin for Low-Density Composites with Bamboo Charcoal

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1100 ◽  
Author(s):  
Yi-Chun Chen ◽  
Wei Tai
Keyword(s):  
Water Absorption ◽  
Castor Oil ◽  
Volume Expansion ◽  
Dibutyltin Dilaurate ◽  
Phyllostachys Pubescens ◽  
Low Density ◽  
Bamboo Charcoal ◽  
Blowing Agent ◽  
Pu Foam ◽  
Pu Foams

Polyurethane (PU) foam adhesives were prepared from castor oil as a polyol with isocyanate poly(4,4’-methylene diphenyl isocyanate) (PMDI) using a solvent-free process. The NCO/OH molar ratio used for the preparation of PU foams was 1.5. Water, organosiloxane and dibutyltin dilaurate were used as the blowing agent, surfactant and catalyst, respectively. The ratio of blowing agent and catalyst were adjusted to optimize the properties. The results show that PU foam prepared with 4 wt % of castor oil catalyst and blowing agent has minimal water absorption and maximal volume expansion in the PU foams. FT-IR analysis shows that a urethane bond was formed by the hydroxyl group of castor oil and the –NCO group of isocyanate PMDI. More blowing agent and catalyst could improve the volume expansion ratio and reduce water retention of PU foams. It was found that Moso bamboo charcoal (Phyllostachys pubescens) and China fir wood particle (Cunninghamia lanceolate) composites with setting densities of 500 and 600 kg/m3 can be prepared from optimized castor oil-based PU foam adhesive at 100 °C for 5 min under a pressure of 1.5 MPa. Increasing the amount of bamboo charcoal decreases the equilibrium moisture content, water absorption and internal bonding strength of the composite. Notably, bamboo charcoal composite exhibits excellent dimensional stability. The optimized density and bamboo charcoal percentages of the composite were 500 kg/m3 and 50–100%, respectively. The castor oil-based PU composites containing bamboo charcoal fulfilled the CNS 2215 standards for particleboard. This dimensionally stable, low-density bamboo charcoal composite has high potential to replace current indoor building materials.

scholarly journals Castor Oil-Based Polyurethane Resin for Low-Density Composites with Bamboo Charcoal

2018 ◽  
Author(s):  
Yi-Chun Chen ◽  
Wei Tai
Keyword(s):  
Water Absorption ◽  
Castor Oil ◽  
Volume Expansion ◽  
Dibutyltin Dilaurate ◽  
Phyllostachys Pubescens ◽  
Low Density ◽  
Bamboo Charcoal ◽  
Blowing Agent ◽  
Pu Foam ◽  
Pu Foams

Polyurethane (PU) foam adhesives were prepared from castor oil as a polyol with isocyanate poly (4,4′-methylene diphenyl isocyanate) (PMDI) using a solvent-free process. The NCO/OH molar ratio used for the preparation of PU foams was 1.5. Water, organosiloxane and dibutyltin dilaurate were blowing agent, surfactant and catalyst, respectively. Effects of the ratio of blowing agent and catalyst were adjusted to optimize the properties. The results show that 4 wt% of castor oil of catalyst and blowing agent minimizes water absorption and maximizes volume expansion in the PU foams. FT-IR analysis shows that urethane bond was formed by hydroxyl group of castor oil and –NCO group of isocyanate PMDI. More blowing agent and catalyst could improve the volume expansion ratio and reduce water retention of PU foams. It was found that Moso bamboo charcoal (Phyllostachys pubescens) or/and China fir wood particle (Cunninghamia lanceolate) composites with setting densities of 500 and 600 kg/m3 can be prepared from optimized castor oil-based PU foam adhesive at 100 °C for 5 min under a pressure of 1.5 MPa. Increasing the amount of bamboo charcoal decreases the equilibrium moisture content, water absorption and internal bonding strength of the composite. Notably, bamboo charcoal composite exhibits excellent dimensional stability. The optimized density and bamboo charcoal percentages of the composite were 500 kg/m3 and 50 to 100%. The castor oil-based PU composites containing bamboo charcoal fulfilled the CNS 2215 standards for particleboard. This dimensionally stable, low-density bamboo charcoal composite has high potential to replace current indoor building materials.

Incorporation of Iraqi Rocks in the Production of Eco-Friendly Cement Mortar

2020 ◽  
Vol 38 (10A) ◽  
pp. 1522-1530
Author(s):  
Rawnaq S. Mahdi ◽  
Aseel B. AL-Zubidi ◽  
Hassan N. Hashim
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Compressive Strength ◽  
Water Absorption ◽  
Structural Properties ◽  
Mechanical Milling ◽  
Cement Mortar ◽  
Cement Mortars

This work reports on the incorporation of Flint and Kaolin rocks powders in the cement mortar in an attempt to improve its mechanical properties and produce an eco-friendly mortar. Flint and Kaolin powders are prepared by dry mechanical milling. The two powders are added separately to the mortars substituting cement partially. The two powders are found to improve the mechanical properties of the mortars. Hardness and compressive strength are found to increase with the increase of powders constituents in the cement mortars. In addition, the two powders affect water absorption and thermal conductivity of the mortar specimens which are desirable for construction applications. Kaolin is found to have a greater effect on the mechanical properties, water absorption, and thermal conductivity of the mortars than Flint. This behavior is discussed and analyzed based on the compositional and structural properties of the rocks powders.

scholarly journals The Effect of Polymer Waste Addition on the Compressive Strength and Water Absorption of Geopolymer Ceramics

2021 ◽  
Vol 11 (8) ◽  
pp. 3540
Author(s):  
Numfor Linda Bih ◽  
Assia Aboubakar Mahamat ◽  
Jechonias Bidossèssi Hounkpè ◽  
Peter Azikiwe Onwualu ◽  
Emmanuel E. Boakye
Keyword(s):  
Public Health ◽  
Compressive Strength ◽  
Fracture Surface ◽  
Water Absorption ◽  
Chemical Bonding ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Polymer Waste ◽  
Pull Out

The quantity of polymer waste in our communities is increasing significantly. It is therefore necessary to consider reuse or recycling waste to avoid an increase in the risk to public health. This project is aimed at using pulverized low-density polyethylene (LDPE) waste as a source to reinforce and improve compressive strength, and to reduce the water absorption of geopolymer ceramics (GC). Clay:LDPE composition consisting of 5%, 10%, and 15% LDPE was geopolymerized with an NaOH/Na2SiO3 solution and cured at 30 °C and 50 °C. Characterization of the geopolymer samples was carried out using XRF and XRD. The microstructure was analyzed by SEM and chemical bonding by FTIR. The SEM micrographs showed LDPE particle pull-out on the geopolymer ceramics’ fracture surface. The result showed that the compressive strength increases with the addition of pulverized polymer waste compared to the controlled without LDPE addition. Water absorption decreased with an increase in LDPE addition in the geopolymer ceramics composite.

Study on Waterproof and Water-Resistant Properties of Gypsum

2012 ◽  
Vol 476-478 ◽  
pp. 1585-1588
Author(s):  
Hong Pan ◽  
Guo Zhong Li
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Portland Cement ◽  
Water Absorption ◽  
Ordinary Portland Cement ◽  
Experimental Results ◽  
Softening Coefficient

The comprehensively modified effect of cement, VAE emulsion and self-made acrylic varnish on mechanical and water-resistant properties of gypsum sample was investigated and microstructure of gypsum sample was analyzed. Experimental results exhibit that absolutely dry flexural strength, absolutely dry compressive strength, water absorption and softening coefficient of gypsum specimen with admixture of 10% ordinary Portland cement and 6% VAE emulsion and acrylic varnish coated on its surface can respectively reach to 5.11MPa , 10.49 MPa, 8.32% and 0.63, respectively.

scholarly journals Astringency in ʻGiomboʼ persimmon and its relationship with the harvest time

Revista CERES ◽  
2016 ◽  
Vol 63 (5) ◽  
pp. 646-652
Author(s):  
Magda Andréia Tessmer ◽  
Beatriz Appezzato-da-Glória ◽  
Ricardo Alfredo Kluge
Keyword(s):  
Cell Wall ◽  
Exposure Time ◽  
Fruit Quality ◽  
Cell Structure ◽  
Parenchyma Cell ◽  
Growing Season ◽  
Ethanol Exposure ◽  
Harvest Time ◽  
Intercellular Spaces ◽  
Parenchyma Cell Wall

ABSTRACT ʻGiomboʼ is one of most cultivated persimmon cultivars in Brazil. It is a late-harvest cultivar and requires treatment for astringency removal. The aim of this study was to evaluate the efficiency of ethanol and the effect of harvest time on reducing astringency, physicochemical and anatomical characteristics of 'Giombo' persimmon. Two experiments were carried out, one in each growing season, with five treatments corresponding to exposure to 1.70 mL kg-1ethanol for 0, 12, 24, 36 and 48 hours. At the end of the growing season (2011) the fruits achieved the astringency index and levels of soluble tannins suitable for consumption in 24 hours, and at the beginning of the growing season (2012) in 36 hours, indicating that the efficiency of the treatment is related to harvest time and ethanol exposure time. Astringency removal with ethanol affects the cell structure with accumulation of substances inside the cells and in intercellular spaces, resulting in the degradation of the parenchyma cell wall. To avoid such damage and maintain fruit quality, it is recommended the combination of low ethanol doses with less ethanol exposure time.

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