A greener and sustainable approach for converting polyurethane foam rejects into superior polyurethane coatings

2019 ◽  
Author(s):  
Chem Int

Recycling is a crucial area of research in green polymer chemistry. Various developments in recycling are driven by Environmental concerns, interest in sustainability and desire to decrease the dependence on non-renewable petroleum based materials. Polyurethane foams [PUF] are widely used due to their light weight and superior heat insulation as well as good mechanical properties. As per survey carried Polyurethane Foam Association, 12 metric tonnes of polyurethane foam are discharged during manufacturing and/or processing and hence recycling of PUF is necessary for better economics and ecological reasons. In present study, rejects of PUF is subjected to reaction with a diethylene amine in presence of sodium hydroxide [NaOH] as catalyst, as a result depolymerised product containing hydroxyl and amine groups is obtained. Conventional and Microwave reaction for depolymerizing polyurethane foam have been carried, and best results are obtained by Microwave reaction. Further depolymerised product with hydroxyl and amine functionalities are reacted with bis (2-hydroxyethyl terephthalate) [BHET] obtained by recycling polyethylene terephthalate [PET] and sebacic acid, with stannous oxalate [FASCAT 2100 series] as catalyst to obtain Polyester amides. These Polyester amides having hydroxyl and amino groups in excess are cured with isocyanates-hexamethylene diisocyanate biuret [HDI biuret] and isophorone diisocyanate [IPDI] for coating applications. The coated films are characterized using physical, mechanical and chemical tests, which shows comparable physical, mechanical properties but alkali resistance is poor.

2008 ◽  
Vol 385-387 ◽  
pp. 205-208 ◽  
Author(s):  
Liviu Marsavina ◽  
Tomasz Sadowski ◽  
Dan Mihai Constantinescu ◽  
Radu Negru

Polyurethane foam materials are widely used as cores in sandwich composites, for packing and cushioning. This paper presents the experimental results obtained for the mechanical properties of polyurethane foams in different loading conditions and the influence of impregnation on the mechanical properties. A 200 kg/m3 density polyurethane foam was tested in tension, compression and three point bending. The experimental results show that the impregnation layer has no effect on the strength of the foam, but has considerable influence on the tensile and flexure modulus.


2008 ◽  
Vol 399 ◽  
pp. 123-130 ◽  
Author(s):  
Liviu Marsavina ◽  
Tomasz Sadowski ◽  
Dan Mihai Constantinescu ◽  
Radu Negru

. Polyurethane foam materials are widely used as cores in sandwich composites, for packing and cushioning. The main characteristics of foams are light weight, high porosity, high crushability and good energy absorption capacity. The paper presents the experimental results obtained for the mechanical properties of polyurethane foams in different loading conditions and the influence of impregnation on the mechanical properties. A 200 kg/m3 density polyurethane foam was investigated in the experimental program in three different Strength of Materials laboratories from Lublin, Bucharest and Timisoara. The paper assesses the possibility to describe the polyurethane foam behaviour trough compression tests, micromechanical models and Finite Element Analysis (FEA). The micromechanical models and Finite Element Analysis could be used successfully for representing the engineering stress – strain behaviour if the compression tests provide reliable material parameters.


2020 ◽  
Vol 56 (5) ◽  
pp. 547-557
Author(s):  
Mohammed Imran ◽  
Ariful Rahaman ◽  
Aabid H Shaik ◽  
Mohammed R Chandan

Addition of fillers in polyurethane foams enhances the mechanical properties of polymeric foams. However, fillers can be loaded to a certain extent, as higher percentage of fillers in polymeric foam causes structural instability leading to the collapse of foam. In this article, we report the use of hollow glass microspheres as a possible co-filler which enables higher loading of nano-clay in flexible polyurethane foam. It has been observed that the structural and mechanical properties of nano-clay-loaded foams were found to cause instability at 5 wt% loading of nano-clay. Therefore, upon addition of hollow glass microspheres in 5 wt%, nano-clay-loaded polyurethane foam shows remarkable enhancement in terms of stability and mechanical properties of the resultant foams. A 100-fold increment in tensile strength has been observed for 2 wt% hollow glass microspheres and 5 wt% nano-clay-loaded flexible polyurethane foams as compared to conventional (unloaded) polyurethane foams.


Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1144 ◽  
Author(s):  
Yangjie Ji ◽  
Shuming Chen ◽  
Yabing Cheng

Polyurethane foam is commonly used in the automobile industry due to its favorable acoustic performances. In this study, a new tung oil-based polyurethane composite foam (TOPUF) was prepared by a one-step method. Different forms and contents of miscanthus lutarioriparius (ML) were used in TOPUF for improving acoustic performance. Polyurethane foams were characterized by means of Fourier transform infrared and SEM. The acoustic properties and mechanical properties of TOPUF, obtained with ML, were determined and compared with pure petroleum-based polyurethane foam. The results illustrate that the modification of TOPUF with the ML has a positive effect on the acoustic and mechanical properties in comparison to the unmodified foam. TOPUF obtained with ML powders has better acoustic performance than that obtained with ML strips. The optimum acoustic performance is achieved at the filler content of 0.3 wt%. The average sound absorption coefficient and transmission loss can reach 0.518, and 19.05 dB, respectively.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Juan Liu ◽  
RiQing Chen ◽  
ChunPeng Wang ◽  
YongJun Zhao ◽  
FuXiang Chu

AbstractA series of phenol-formaldehyde-polyethylene glycol polyether polyols (PF-PEGs) were synthesized through the condensation polymerization and etherification of phenol, formaldehyde, and poly(ethylene glycol) (PEG) under alkaline conditions and subsequently reacted with 1,6-hexamethylene diisocyanate to obtain polyurethane (PU) films using acetone as solvents. The influence of phenol and formaldehyde to PEG mass ratio ((P + F)/PEG) on the hydroxyl number of PF-PEGs and mechanical properties, thermal stabilities, crystallization behaviors, as well as microstructure of polyurethane composite films were studied using chemical analysis, mechanical tests, thermogravimetric analyses (TGA), dynamic mechanical analyses (DMA), X-ray diffraction (XRD), scanning and transmission electron microscopies (SEM and TEM), respectively. Results demonstrated that PF-PEGs with (P + F)/PEG of 50/50 had the highest hydroxyl number of 323 mg K(OH)/g. The incorporation of phenol and formaldehyde into PEG improved the mechanical properties of polyurethane films, glass transition temperature (Tg), and thermal properties but resulted in the brittleness characteristic of the composite films and low crystallization properties. Moreover, the synthesis mechanism of PF-PEGs polyurethane composite films was revealed, which would provide a theoretical base for the preparation of the rigid polyurethane foams based on phenolic resins.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1801
Author(s):  
Rafał Oliwa ◽  
Joanna Ryszkowska ◽  
Mariusz Oleksy ◽  
Monika Auguścik-Królikowska ◽  
Małgorzata Gzik ◽  
...  

We investigated the effect of the type and amount of expandable graphite (EG) and blackcurrant pomace (BCP) on the flammability, thermal stability, mechanical properties, physical, and chemical structure of viscoelastic polyurethane foams (VEF). For this purpose, the polyurethane foams containing EG, BCP, and EG with BCP were obtained. The content of EG varied in the range of 3–15 per hundred polyols (php), while the BCP content was 30 php. Based on the obtained results, it was found that the additional introduction of BCPs into EG-containing composites allows for an additive effect in improving the functional properties of viscoelastic polyurethane foams. As a result, the composite containing 30 php of BCP and 15 php of EG with the largest particle size and expanded volume shows the largest change in the studied parameters (hardness (H) = 2.65 kPa (+16.2%), limiting oxygen index (LOI) = 26% (+44.4%), and peak heat release rate (pHRR) = 15.5 kW/m2 (−87.4%)). In addition, this composite was characterized by the highest char yield (m600 = 17.9% (+44.1%)). In turn, the change in mechanical properties is related to a change in the physical and chemical structure of the foams as indicated by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) analysis.


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

RSC Advances ◽  
2015 ◽  
Vol 5 (69) ◽  
pp. 55879-55891 ◽  
Author(s):  
Águeda Sonseca ◽  
Oscar Sahuquillo ◽  
E. Johan Foster ◽  
Enrique Giménez

Two pre-polymers with ad-mannitol : sebacic acid 1 : 1 and 1 : 2 ratios respectively were combined with cellulose nanocrystals (CNCs) and crosslinked applying different time–temperature profiles to obtain PMS/CNC nanocomposites with different properties.


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