Preliminary Mechanical Characterization of Reinforced Rigid Polyurethane Foams

Author(s):  
Nagesh Kasichainula ◽  
Sanjeev K. Khanna

Rigid polyurethane foams are very widely used in a variety of structural and non-structural applications. For example, it may be used as an insulator, in sandwich layered composite panels, and as filler for improving the stiffness of lightweight components, such as thin metal tubes. Rigid foams do not show any recovery after impact and typically are crushed or crumble. They also tend to degrade over a period of time. Thus in this investigation, reinforced rigid polyurethane foams have been developed and characterized for their quasi-static mechanical properties. Rigid polyurethane foam was reinforced with short, 0.47 mm length, milled E-glass fibers. It has been observed that short glass fiber reinforcement helps in improving the mechanical properties, such as tensile modulus, breaking strength, and compression modulus, of the reinforced foam as compared to monolithic foam.

Author(s):  
Mehran Tehrani ◽  
Ayoub Y. Boroujeni ◽  
Timothy B. Hartman ◽  
Thomas P. Haugh ◽  
Scott W. Case ◽  
...  

Carbon fiber reinforced plastics (CFRPs) possess superior in-plane mechanical properties and are widely used in structural applications. Altering the interphase of CFRPs could alleviate the shortcomings of their out-of-plane performance. In this work, the effects of adding multi-walled carbon nanotubes (MWCNTs) to the epoxy matrix of a CFRP are investigated. Two sets of CFRPs with matrices comprising MWCNTs/epoxy and neat epoxy, respectively, were fabricated. The tensile properties of the two systems, namely the stiffness, the ultimate strength, and the strain to failure were evaluated. The results of the tension tests showed slight changes on the on-axis (along the fiber) tensile modulus and strength of the carbon fiber reinforced epoxy/MWCNT compared to composites with no MWCNTs. The addition of MWCNTs to the matrix moderately increased the strain to failure of the composite. Energy absorption capabilities for the two sets of composites under an intermediate impact velocity (100 m.s−1) test were measured. The energy dissipation capacity of the CFRPs incorporating MWCNTs was higher by 17% compared to the reference CFRPs.


2004 ◽  
Vol 36 (4) ◽  
pp. 333-349 ◽  
Author(s):  
Bo Yin ◽  
Zhong-Ming Li ◽  
Hui Quan ◽  
Ming-Bo Yang ◽  
Qiu-Ming Zhou ◽  
...  

2021 ◽  
Author(s):  
Chao Chen ◽  
Qingong Zhu ◽  
Huanping Wang ◽  
Feifei Huang ◽  
Qinghua Yang ◽  
...  

Abstract As is well known, silicate glass has a stable glass-forming region and mature drawing processes into fibers. In this study, to obtain enhanced mechanical properties, glasses with a composition of SiO2-Al2O3-MgO-CaO-B2O3-Fe2O3 were synthesized using TiO2 and CeO2. When the amount of TiO2 and CeO2 is less than 2 wt%, the mechanical properties increase with increases in the TiO2 and CeO2. However, as the amount of TiO2 and CeO2 increases from 2 to 3.5 wt%, the mechanical properties decrease. Co-doping with 1 wt% TiO2 and 1 wt% CeO2 was found to be the optimum approach, with a density, bending strength, compression strength, and compression modulus of 2.626 g/cm3, 108.36 MPa, 240.18 MPa, and 115.03 GPa, respectively. The optical band gap and Raman spectroscopy proved that, as long as the content of oxygen bonds reaches the maximum level, a kind of best structural stability and mechanical properties will be achieved. Hence, this type of high-strength silicate glass can be used in optical fibers for military defense, wind power generation, and transportation.


2019 ◽  
Vol 24 ◽  
pp. 1-7
Author(s):  
Md. Naimul Islam ◽  
Harun Ar-Rashid ◽  
Farhana Islam ◽  
Nanda Karmaker ◽  
Farjana A. Koly ◽  
...  

E-glass fiber mat reinforced Unsaturated Polyester Resin (UPR)-based composites were fabricated by conventional hand lay-up technique. The fiber content was varied from 5 to 50% by weight. Mechanical properties (tensile and bending) of the fabricated composites were investigated. The tensile strength (TS) of the 5% and 50% fiber reinforced composites was 32 MPa and 72 MPa, respectively. Similarly, tensile modulus, bending strength and bending modulus of the composites were increased by the increase of fiber loading. Interfacial properties of the composites were investigated by scanning electron microscopy (SEM) and the results revealed that the interfacial bond between fiber and matrix was excellent. Keywords: Unsaturated Polyester Resin, Mechanical Properties, E-glass Fibers, Composites, Polymer.


Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2725 ◽  
Author(s):  
Jānis Andersons ◽  
Mikelis Kirpluks ◽  
Ugis Cabulis

Rigid low-density closed-cell polyurethane (PU) foams are widely used in both thermal insulation and structural applications. The sustainability of PU foam production can be increased by using bio-based components and fillers that ensure both enhanced mechanical properties and higher renewable material content. Such bio-based foams were produced using polyols derived from rapeseed oil and microcrystalline cellulose (MCC) fibers as filler. The effect of MCC fiber loading of up to 10 wt % on the morphology, tensile stiffness, and strength of foams has been evaluated. For estimation of the mechanical reinforcement efficiency of foams, a model allowing for the partial alignment of filler fibers in foam struts was developed and validated against test results. It is shown that although applying MCC fibers leads to modest gains in the mechanical properties of PU foams compared with cellulose nanocrystal reinforcement, it may provide a higher content of renewable material in the foams.


Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 336 ◽  
Author(s):  
Sylwia Członka ◽  
Anna Strąkowska ◽  
Krzysztof Strzelec ◽  
Agnieszka Adamus-Włodarczyk ◽  
Agnė Kairytė ◽  
...  

Rigid polyurethane foams (RPUFs) were successfully modified with different weight ratios (0.5 wt%, 1.5 wt% and 5 wt%) of APIB-POSS and AEAPIB-POSS. The resulting foams were evaluated by their processing parameters, morphology (Scanning Electron Microscopy analysis, SEM), mechanical properties (compressive test, three-point bending test and impact strength), viscoelastic behavior (Dynamic Mechanical Analysis, DMA), thermal properties (Thermogravimetric Analysis, TGA, and thermal conductivity) and application properties (contact angle, water absorption and dimensional analysis). The results showed that the morphology of modified foams is significantly affected by the type of the filler and filler content, which resulted in inhomogeneous, irregular, large cell shapes and further affected the physical and mechanical properties of resulting materials. RPUFs modified with APIB-POSS represent better mechanical and thermal properties compared to the RPUFs modified with AEAPIB-POSS. The results showed that the best results were obtained for RPUFs modified with 0.5 wt% of APIB-POSS. For example, in comparison with unfilled foam, compositions modified with 0.5 wt% of APIB-POSS provide greater compression strength, better flexural strength and lower water absorption.


2015 ◽  
Vol 3 (12) ◽  
pp. 3382-3387 ◽  
Author(s):  
Lorena Ugarte ◽  
Sandra Gómez-Fernández ◽  
Cristina Peña-Rodrı́uez ◽  
Aleksander Prociak ◽  
Maria Angeles Corcuera ◽  
...  

2007 ◽  
Vol 105 (5) ◽  
pp. 2988-2995 ◽  
Author(s):  
Zhongbin Xu ◽  
Xiling Tang ◽  
Aijuan Gu ◽  
Zhengping Fang ◽  
Lifang Tong

Polymer ◽  
2018 ◽  
Vol 153 ◽  
pp. 616-625 ◽  
Author(s):  
Shui-Xiu Wang ◽  
Hai-Bo Zhao ◽  
Wen-Hui Rao ◽  
Sheng-Chao Huang ◽  
Ting Wang ◽  
...  

2017 ◽  
Vol 7 ◽  
pp. 184798041668411 ◽  
Author(s):  
Caterina Lorusso ◽  
Viviana Vergaro ◽  
Francesca Conciauro ◽  
Giuseppe Ciccarella ◽  
Paolo Maria Congedo

This study investigates the effects of commercial nanoparticles on thermal and mechanical performance of rigid polyurethane foams. Two different types of nanoparticles are considered as fillers, spherical titania and rod-shaped halloysite clay nanotubes. The aim of this study was to produce rigid polyurethane foams modified with titania nanocrystals and nanohalloysite in order to obtain polyurethanes with improved properties. The laboratory scale-up will be suitable for the production in many branches of industry, such as construction and automotive production. In particular, these foams, added with commercial nanoparticles, characterized by better thermal and mechanical properties, are mainly used in construction for thermal insulation of buildings. The fillers were dispersed in the components, bringing rates up to 10%. In these investigations, the improvement of the thermal properties occurs by adding nanoparticles in the range 4–8% of titania and halloysite. The mechanical properties instead have been observed an improvement starting from 6% of nanoparticles addition. All data are in agreement with scanning electron microscope observations that shown a decrease in the average cell size and an increase in the cell density by adding nanoparticles in foams.


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