Submit to Special Issue Submit Abstract to Special Issue Review for Polymers Propose a Special Issue

Journal Menu

Journal Browser

► Journal Browser

Polyurethane Foams

Print Special Issue Flyer
Editor
Special Issue Information
Keywords
Benefits of Publishing in a Special Issue
Published Papers

A Special Issue of Polymers (ISSN 2073-4360) belonging to the section "Polymer Applications".

Deadline for manuscript submissions: 30 November 2026 | Viewed by 3419

Share This Special Issue

Editor

Dr. Elżbieta Malewska

E-Mail Website
Guest Editor

Department of Chemistry and Technology of Polymers, Cracow University of Technology, Warszawska 24, 31-155 Kraków, Poland
Interests: synthesis, structure, and properties of polyurethane materials; polyurethane foams; development of sustainable solutions; bio-based raw materials; chemical recycling of polyurethanes; relationships between chemical composition, cellular structure, and the application of foamed materials
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

This Special Issue “Polyurethane Foams” aims to present the latest research and developments related to the synthesis, structure, properties and applications of polyurethane foams. The global production of polyurethanes continues to grow, with more than half of the total output consisting of flexible and rigid foams widely used in the furniture, automotive and construction industries.

In light of these trends, increasing attention is being paid to the search for new renewable raw materials that could replace petrochemical-based feedstocks, as well as to meeting growing environmental requirements, including the phasing-out of certain physical blowing agents and chlorine-containing flame retardants.

This Special Issue welcomes contributions focused on innovative raw materials, including bio-based polyols and sustainable additives, as well as novel processing methods and recycling strategies for polyurethane foams. Particular attention will be devoted to the relationships between chemical composition, cellular structure and foam applications by different industries branches. Both experimental and modeling studies, as well as comprehensive review articles, are highly encouraged.

Dr. Elżbieta Malewska
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 250 words) can be sent to the Editorial Office for assessment.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-anonymized peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Polymers is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

polyurethane foams
flexible foam
rigid foam
bio-based polyols
recycling
cellular structure
mechanical properties
thermal insulation
structure–property relationship
processing methods

Benefits of Publishing in a Special Issue

Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
Reprint: MDPI Books provides the opportunity to republish successful Special Issues in book format, both online and in print.

Further information on MDPI's Special Issue policies can be found here.

Published Papers (4 papers)

Download All Papers

Order results

Result details

Show export options Show export options

Select all

Export citation of selected articles as:

Research

24 pages, 21811 KB

Open AccessArticle

Predicting Mechanical Properties of Lignin-Containing Polyurethane Rigid Foams from Microstructure Using Convolutional Neural Networks

by Ilige S. Hage, Charbel Y. Seif, Jose Enrico Q. Quinsaat, Daniel J. Van De Pas, Richard Vendamme, Walter Eevers, Karolien Vanbroekhoven and Elias Feghali

Polymers 2026, 18(18), 2229; https://doi.org/10.3390/polym18182229 - 12 Sep 2026

Viewed by 337

Abstract

Bio-based alternatives to conventional rigid foams have proven to be good substitutes owing to their enhanced sustainability and competitive performance. However, because their manufacturing processes are complex and destructive testing is often impractical, this study investigates whether microstructural features can be correlated with mechanical properties in lignin-containing rigid polyurethane (PU) foams using machine learning approaches. Various types and percentages of lignin-based polyols were investigated as partial replacements for polyol, including LHO, DCA, DCA-D, LHO-O, Kraft lignin (KL), and LHO-MD, at polyol replacement levels ranging from 12.5% to 50%, together with a control formulation. Scanning electron microscopy (SEM) images and corresponding mechanical compression data were used to train a custom state-of-the-art dual-head convolutional neural network (CNN) targeting the specific prediction of density, specific compression modulus, specific yield stress, and specific compression strength. The CNN was optimized with a weighted multi-output loss function, achieving strong predictive performance with R² values ranging from 0.850 to 0.91 and correlation coefficients above 0.92, while maintaining mean absolute error percentages below ≈9%. This proves the trained network’s capability to predict and capture morphological features governing load-bearing responses. On the other hand, Grad-CAM visualization revealed that the network focused its predictions on physically meaningful microstructural regions such as cell walls and strut junctions, which confirms that the proposed network can be classified as an interpretable, non-destructive, and data-driven framework for predicting and understanding bio-based PU foams’ mechanical behavior, hence reducing the inconvenience caused by time-consuming manufacturing and destructive testing. Full article

(This article belongs to the Special Issue Polyurethane Foams)

► Show Figures

Figure 1

19 pages, 3185 KB

Open AccessArticle

Impact Absorption Optimization in Rigid Polyurethane Foams Modified with Diethanolamine

by Tatiana Francisco, Fabio Oliveira, Rosana Moreira, Elcio Cruz de Oliveira and Diego Souza

Polymers 2026, 18(14), 1741; https://doi.org/10.3390/polym18141741 - 16 Jul 2026

Viewed by 457

Abstract

Rigid polyurethane foams are used in impact-attenuation systems due to their tunable cellular structure and energy dissipation capacity. However, expanded polystyrene (EPS), commonly used for impact protection, presents limitations related to impact attenuation performance and limited design flexibility. This study evaluates the impact performance of rigid polyurethane foams modified with diethanolamine and assesses formulation efficiency using Data Envelopment Analysis (DEA). Rigid PU foam formulations containing 0–3 wt% DEOA were synthesized and characterized by impact testing, apparent density measurements, Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, and Thermogravimetric Analysis/Derivative Thermogravimetry. DEA was applied to correlate diethanolamine content with impact absorption efficiency. Excessive crosslinking and reduced energy dissipation were observed above 2 wt%, while concentrations below 0.5 wt% resulted in poorly structured foams. The formulation containing 1 wt% DEOA was identified as the most efficient among the investigated formulations, exhibiting the best overall performance, reducing transmitted peak acceleration by 13.8% compared with neat PU foam, while exhibiting an approximately 48% increase in apparent density, more complete consumption of NCO groups, a more uniform cellular structure, and only modest changes in thermal degradation behavior. These findings indicate that the improved impact performance is associated with the combined effects of increased apparent density, modified cellular morphology, and changes in the polyurethane network promoted by DEOA, underscore the promise of diethanolamine-modified rigid polyurethane (PU) foams for protective applications. Full article

(This article belongs to the Special Issue Polyurethane Foams)

► Show Figures

Graphical abstract

20 pages, 3633 KB

Open AccessArticle

Impact of Suberin Depolymerization Conditions on the Thermal Properties and Flammability of Rigid Polyurethane Foams

by Aiga Ivdre, Mikelis Kirpluks, Daniela Godina, Arnis Abolins, Laima Vevere, Rudolfs Berzins, Maris Lauberts and Janis Rizikovs

Polymers 2026, 18(11), 1355; https://doi.org/10.3390/polym18111355 - 29 May 2026

Viewed by 411

Abstract

Suberinic acids (SA) derived from birch outer bark are renewable feedstocks for bio-based polyols suitable for rigid polyurethane (PU) foams. Three SA fractions were prepared under different depolymerization conditions: acidification at pH 1 (SA1), pH 5 (SA2), and FeCl₃-assisted treatment (SA3), and their chemical composition was analysed by GC–MS, Py–GC/MS, and GPC–RID. Polyols derived from tall oil fatty acids (TOFA) or epoxidized TOFA with trimethylolpropane were used as the sole polyol components in foam formulations. The SA fractions differed in molecular weight distribution, affecting polyol processability. All foams exhibited similar limiting oxygen index (19–20) and cone calorimetry results, showing no statistically significant differences in flammability. This indicates that variations in depolymerization conditions, including polyphenolic content and removal of higher-molecular-weight fractions during FeCl₃ treatment, do not dominate fire performance under the studied conditions. SA3-based polyols showed the lowest viscosity and produced foams with optimal mechanical and thermal properties, while SA1 offered higher yield with comparable performance. These results demonstrate the feasibility of converting SA fractions into functional polyols for rigid PU foams and highlight the FeCl₃-treated SA3 fraction and SA1 as the most promising candidates for further development. Full article

(This article belongs to the Special Issue Polyurethane Foams)

► Show Figures

Figure 1

17 pages, 2780 KB

Open AccessArticle

Bio-Based Viscoelastic Polyurethane Foams: Functional Behavior Across Application Temperatures

by Elżbieta Malewska, Konstantinos N. Raftopoulos, Piotr Rytlewski, Sławomir Michałowski, Natalia Koman, Maria Kurańska and Aleksander Prociak

Polymers 2026, 18(2), 174; https://doi.org/10.3390/polym18020174 - 8 Jan 2026

Cited by 4 | Viewed by 1574

Abstract

Viscoelastic polyurethane foams were prepared using four different bio-based polyols derived from coconut oil (CO), palm oil (PO), duck fat (DF), and pork fat (PF), employing up to 20 wt.% of the polyol component in a conventional formulation. The introduction of bio-polyols into the polyurethane formulation gave rise to an early minor decomposition of modified foams at low temperatures; however, the overall thermal stability improved slightly by the elimination of some intermediate decomposition stages. The glass transition temperature of foams was only moderately influenced and remained in the typical temperature range (around 10 °C). The effect of biopolyol type and content (5–20 wt.%) on the mechanical properties of the foams was investigated over the temperature range −20 to 40 °C. At 20 and 40 °C, all foams exhibited comfortable viscoelastic properties suitable for furniture applications. Hysteresis and the damping behavior of foams were also influenced by biopolyol type and concentration, with CO and DF providing enhanced energy absorption. Overall, these bio-based foams demonstrate potential for eco-friendly, high-performance applications, although their use at temperatures below 10 °C may be limited by increased stiffness. Full article

(This article belongs to the Special Issue Polyurethane Foams)

► Show Figures

Journal Menu

Journal Browser

Polyurethane Foams

Share This Special Issue

Editor

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (4 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI