Low density rigid polyurethane foam incorporated with renewable polyol as sustainable thermal insulation material

2022 ◽  
pp. 0021955X2110626
Author(s):  
Adnan Srihanum ◽  
Maznee TI Tuan Noor ◽  
Kosheela PP Devi ◽  
Seng Soi Hoong ◽  
Nurul H Ain ◽  
...  

Palm olein-based polyol (PP) was used as a partial replacement for commercial sucrose/glycerine initiated polyether polyol (GP) for the production of low density rigid polyurethane foams (RPUFs). The hydroxyl value (OHV) of the GP was 380 mg KOH/g, whereas the OHV for PP was 360 mg KOH/g. The RPUFs were prepared by replacing the GP with PP up to 50 parts per hundred parts of polyols (pph). Characterisation of the RPUFs, including density, compressive strength and strain, cell morphology and thermal conductivity ( k-value), were conducted. The dimensional stability of the foams was also evaluated. The study showed improvement in the compressive strength and strain for palm-based RPUFs with the incorporation of up to 30 pph PP as compared to GP foams. The lowest k-value (0.0232 W/m.K) of RPUF with density below 30 kg/m3 was obtained with the incorporation of 10 pph PP. This was due to the smallest and uniform pore size distribution observed using SEM images. The dimensional stability of the RPUF prepared from PP was within the acceptable range. Thus, the RPUFs made from PP are potential candidates to be used as insulation for refrigerators, freezers and piping.

2020 ◽  
Vol 6 (10) ◽  
pp. 1932-1943
Author(s):  
Alvin Joseph Santos Dolores ◽  
Jonathan David Lasco ◽  
Timothy M. Bertiz ◽  
Kimjay M. Lamar

Infusing plastic waste to concrete and masonry structures is an increasingly common industry practice that has the potential to create an environment-friendly material that can improve some of the material’s properties, craft a novel means to repurpose plastic waste, and reduce the need for mining aggregates in the environment. This concept has been studied extensively in different forms of concrete, as shown by several studies; however, there is a dearth of studies focusing on the incorporation plastic waste in concrete hollow blocks (CHB). In this study, we aim to fill that gap by investigating on the effects of incorporating low-density polyethylene (LDPE), a commonly used plastic material, to CHB on its compressive strength and bulk density. Samples of varying percentages of LDPE replacement by volume (0, 10, 20, 30 and 40%) were fabricated and tested. Results showed a general trend of decreasing compressive strength and bulk density upon increasing the amount of LDPE pellets in CHB, which was also observed in previous studies. However, the compressive strength of CHB increased at 10% LDPE replacement, a result similar to a previous study. It was inferred that the strength of the plastic material could have a direct contribution to the compressive strength of CHB at low percentage of aggregate replacement. Statistical analysis showed that the mix with 10% LDPE pellets as replacement to sand was the best among the samples tested. It was shown that CHB infused with LDPE pellets has a higher compressive strength than what is normally used in the Philippines. It was concluded that based on compressive strength and bulk density, LDPE pellets is a viable material to use as partial replacement to sand in non-load bearing CHB.


2013 ◽  
Vol 357-360 ◽  
pp. 1441-1445
Author(s):  
Xiao Lin Li ◽  
Zheng Fang ◽  
Dong Ji ◽  
Zhi Dong Wan ◽  
Kai Guo

The synthesis of a novel class of diamine-based polyols derivatives and the potentials and the limitations of these polyols were reported. This class of diamine-based polyols with high hydroxyl values and no acid values can be used in rigid polyurethane foams. The prepared rigid foams show the properties of low density, high closed cell content, low thermal conductivity, and high compressive strength.


2014 ◽  
Vol 887-888 ◽  
pp. 727-730
Author(s):  
Meng Zhang ◽  
Li Qiang Zhang ◽  
Yong Hong Zhou

Rosin based polyether polyols were synthesized from rosin formaldehyde adduct, propylene epoxide and ethylene epoxide in the presence of catalyst. Rigid polyurethane foams (PUFs) were prepared with these rosin-based polyols and compared with foam made with an industrial polyether polyol (TC-4110) and rosin-based polyester polyols. The mechanical and thermal properties of foams were analyzed by some methods. The experimental results show that the foaming behavior for the foams prepared from such rosin based polyether polyols is similar to that of industrial products, but the reaction activities were higher, the viscosities are much lower. Furthermore, their 10% compression strength and thermal stability were higher and the dimensional stability is similar or somewhat better than that of TC-4110 system. All these unique properties of rigid PUFs made with rosin based polyether polyols were more suitable for as industrial production.


2021 ◽  
Vol 13 (13) ◽  
pp. 7157
Author(s):  
Hamidul Bari ◽  
Md. Safiuddin ◽  
Md. Abdus Salam

In this study, coconut shell aggregate (CSA) was used in brick aggregate concrete (BAC) to produce structural lightweight concrete. Various BACs containing CSA (CSBACs) were prepared based on the volumetric mix ratio of 1:1.5:3 (cement:fine aggregate:coarse aggregate). CSA was used substituting 0−15% of brick aggregate (BA) by weight. The concrete mixes were designed based on the weight-based water to cement (w/c) ratios of 0.45, 0.50, and 0.55. All the freshly mixed concretes were tested for their workability with respect to slump. In addition, the freshly mixed concretes made with the w/c ratio of 0.50 were examined for their wet density and air content. The hardened concretes were tested for their dry density, compressive strength, and microstructural characteristics (e.g., microcrack, micropore, fissure). The microstructure of CSBACs was investigated by a scanning electron microscope (SEM). In addition, the fissure width between the cement paste and CSA was measured from the SEM images using “ImageJ” software. The correlation between the compressive strength and fissure width of CSBAC was also examined. Test results showed that the air content of CSBACs including 5–15% CSA was higher than that of the control concrete (0% CSA). In addition, the density and compressive strength of concrete decreased with the increased CSA content. Above all, the most interesting finding of this study was the presence of fissures in the interfacial transition zone between the cement paste and CSA of CSBAC. The fissure width gradually increased with the increase in CSA content and thus decreased the compressive strength of concrete. However, the fissure width decreased with the increased curing age of concrete and therefore the compressive strength of CSBAC was enhanced at later ages. Moreover, a good correlation between the compressive strength and fissure width of CSBAC was observed in this study.


Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1392 ◽  
Author(s):  
Guangyu Zhang ◽  
Yumin Wu ◽  
Weisheng Chen ◽  
Dezhi Han ◽  
Xiaoqi Lin ◽  
...  

Bio-based polyurethane materials with abundant open-cells have wide applications because of their biodegradability for addressing the issue of environmental conservation. In this work, open-cell rigid polyurethane foams (RPUFs) were prepared with bio-based polyols (BBPs) derived from the liquefaction of peanut shells under different post-processing conditions. The influences of the neutralization procedure and filtering operation for BBPs on the foaming behaviors, density, dimensional stability, water absorption, swelling ratio, compressive strength, and microstructure of RPUFs were investigated intensively. The results revealed that a small amount of sulfuric acid in the polyols exhibited a great impact on physical and chemical properties of RPUFs while the filtering operation for those polyols had a slight effect on the above properties. The RPUFs prepared from neutralized BBPs possessed higher water absorption, preferable dimensional stability and compression strength than that fabricated from the non-neutralized BBPs. Moreover, the prepared RPUFs exhibited preferable water absorption of 636–777%, dimensional stability of <0.5%, compressive strength of >200 KPa, lower swelling rate of ca. 1%, as well as uniform cell structure with superior open-cell rate, implying potential applications in floral foam.


Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6263
Author(s):  
Ala Abu Abu Taqa ◽  
Mohamed Al-Ansari ◽  
Ramzi Taha ◽  
Ahmed Senouci ◽  
Ghaleb M. Al-Zubi ◽  
...  

This study investigated the potential utilization of the TBM muck obtained from the Gold Line of the Doha Metro Project as a partial replacement of coarse aggregates in concrete mixes. First, the TBM muck particles were screened to coarse aggregate standard sizes. Then, concrete mixes were prepared using 0%, 25%, 50%, and 75% TBM muck replacement of coarse aggregates. The compressive and flexural strengths were determined for all mixes at 28 and 56 days. Moreover, the results obtained were validated using EDX analysis and SEM images. A t-statistical analysis did not show a significant impact of TBM muck usage on the compressive strength results of the concrete mixes. However, another t-statistical analysis showed that TBM muck replacement of coarse aggregates had adversely affected the flexural strength results. The EDX analysis indicated the presence of Na+ ions, which can replace the Ca2+ ions in the C-S-H gel, cause discontinuities of it, and hence reduce the strength at later ages. Finally, the SEM images showed that the ettringite and carbon hydroxide (C-H) contents in the mixes with TBM muck were higher than that of the control mix, while the C-S-H gel was less in such mixes.


Alloy Digest ◽  
1988 ◽  
Vol 37 (3) ◽  

Abstract COMPAX is a chromium-molybdenum shock-resistant tool steel characterized by high toughness, good wear resistance, good through hardening and good dimensional stability during hardening. This datasheet provides information on composition, physical properties, hardness, elasticity, and compressive strength. It also includes information on heat treating, machining, joining, and surface treatment. Filing Code: TS-488. Producer or source: Uddeholm Steel Corporation.


2021 ◽  
Vol 11 (7) ◽  
pp. 3032
Author(s):  
Tuan Anh Le ◽  
Sinh Hoang Le ◽  
Thuy Ninh Nguyen ◽  
Khoa Tan Nguyen

The use of fluid catalytic cracking (FCC) by-products as aluminosilicate precursors in geopolymer binders has attracted significant interest from researchers in recent years owing to their high alumina and silica contents. Introduced in this study is the use of geopolymer concrete comprising FCC residue combined with fly ash as the requisite source of aluminosilicate. Fly ash was replaced with various FCC residue contents ranging from 0–100% by mass of binder. Results from standard testing methods showed that geopolymer concrete rheological properties such as yield stress and plastic viscosity as well as mechanical properties including compressive strength, flexural strength, and elastic modulus were affected significantly by the FCC residue content. With alkali liquid to geopolymer solid ratios (AL:GS) of 0.4 and 0.5, a reduction in compressive and flexural strength was observed in the case of geopolymer concrete with increasing FCC residue content. On the contrary, geopolymer concrete with increasing FCC residue content exhibited improved strength with an AL:GS ratio of 0.65. Relationships enabling estimation of geopolymer elastic modulus based on compressive strength were investigated. Scanning electron microscope (SEM) images and X-ray diffraction (XRD) patterns revealed that the final product from the geopolymerization process consisting of FCC residue was similar to fly ash-based geopolymer concrete. These observations highlight the potential of FCC residue as an aluminosilicate source for geopolymer products.


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