Screening Life Cycle Assessment of Tall Oil-Based Polyols Suitable for Rigid Polyurethane Foams

Comprehensive Enhancement of Prepolymer-Based Flexible Polyurethane Foams' Performance by Introduction of Cost-Effective Waste-Based Ground Tire Rubber Particles

Material innovations in polyurethane (PU) foams should ideally combine performance enhancement, environmental impact limitation, and cost reduction. These goals can be achieved by applying recycled or waste-based materials without broader industrial applications, implicating their low price. Herein, from 5 to 20 parts by weight of ground tire rubber (GTR) particles originated from the recycling of postconsumer car tires were incorporated into a flexible foamed PU matrix as a cost-effective waste-based filler. A two-step prepolymer method of foams manufacturing was applied to maximize the potential of applied formulation changes. The impact of the GTR content on the foams' processing, chemical, and cellular structure, as well as static and dynamic mechanical properties, thermal stability, sound suppression ability, and thermal insulation performance, was investigated. The introduction of GTR caused a beneficial reduction in the average cell diameter, from 263.1 µm to 144.8-188.5 µm, implicating a 1.0-4.3% decrease in the thermal conductivity coefficient. Moreover, due to the excellent mechanical performance of the car tires-the primary application of GTR-the tensile performance of the foams was enhanced despite the disruption of the cellular structure resulting from the competitiveness between the hydroxyl groups of the applied polyols and on the surface of the GTR particles. The tensile strength and elongation at break were increased by 10 and 8% for 20 parts by weight GTR addition. Generally, the presented work indicates that GTR can be efficiently applied as a filler for flexible PU foams, which could simultaneously enhance their performance, reduce costs, and limit environmental impacts due to the application of waste-based material.

Scale-Up and Testing of Polyurethane Bio-Foams as Potential Cryogenic Insulation Materials

This article compares the properties of closed-cell PUR bio-foams produced on a laboratory scale and on an industrial scale. In the formulation used, the polyol premix contained 40 wt.% of a bio-polyol based on rapeseed oil. Selected useful properties of the foams obtained on the two scales and the use of one-step and spraying methods were compared. In the case of the spraying method, the experimental system was compared to a commercial one. Given the possibility of applying the bio-foams in insulation systems for cryogenic and liquefied natural gas (LNG) applications, a compressive strength analysis of the foams was carried out at room temperature as well as at −196 °C. It was found that the foams modified with the bio-polyol were characterized by a higher compressive strength at low temperatures than commercial foams based on a petrochemical polyol.

Recent Advances in Development of Waste-Based Polymer Materials: A Review

Limited petroleum sources, suitable law regulations, and higher awareness within society has caused sustainable development of manufacturing and recycling of polymer blends and composites to be gaining increasing attention. This work aims to report recent advances in the manufacturing of environmentally friendly and low-cost polymer materials based on post-production and post-consumer wastes. Sustainable development of three groups of materials: wood polymer composites, polyurethane foams, and rubber recycling products were comprehensively described. Special attention was focused on examples of industrially applicable technologies developed in Poland over the last five years. Moreover, current trends and limitations in the future “green” development of waste-based polymer materials were also discussed.

A Pathway toward a New Era of Open-Cell Polyurethane Foams-Influence of Bio-Polyols Derived from Used Cooking Oil on Foams Properties

In order to create greener polyurethane (PUR) foams, modified used cooking oils (UCO) were applied as starting resources for the synthesis of bio-polyols. The bio-polyols were produced using transesterification of UCO with diethylene glycol (UCO_DEG) and triethanolamine (UCO_TEA). Next, open-cell PUR foams were synthesized by replacing 20, 40, 60, 80 and 100% of the petrochemical polyol with the bio-polyol UCO_DEG or UCO_TEA. It was observed that an increasing bio-polyol content (up to 60%) led to an increase of the closed cell content. However, a further increase in the bio-polyol content up to 100% resulted in foam cell opening. The bio-foams obtained in the experiment had an apparent density of 13–18 kg/m³. The coefficient of thermal conductivity was determined at three different average temperatures: 10, 0 and −10 °C. The PUR bio-foams modified with bio-polyol UCO_TEA had lower values of thermal conductivity, regardless of the average temperature (35.99–39.57 mW/m·K) than the foams modified with bio-polyol UCO_DEG (36.95–43.78 mW/m·K). The compressive strength of most of the bio-foams was characterized by a higher value than the compressive strength of the reference material (without bio-polyol). Finally, it was observed that the bio-materials exhibited dimensional stability at 70 °C.