Rethinking Polyester Polyurethanes

Rethinking Polyester Polyurethanes: Algae Based Renewable, Sustainable, Biodegradable and Recyclable Materials explains how and why bio-based materials, specifically algae, will change the polymer industry. The book provides background on algae, polyurethanes (PUs), and their everyday use. It covers the biology and chemistry behind how and why these materials are engineered to be both biodegradable and, through the process of depolymerization, fully recyclable. Chapters cover Re-evaluating the Sources, Redefining the Analytics, Reformulating Polyester Polyurethanes, and The Future. The latter part of the book describes the landscape of bio-based materials, the eco-consumer, and insights into the industry problem of “greenwashing. This book is a valuable resource for industry professionals who use polyurethanes in the supply chain for manufactured products, those in sales and marketing or regulatory roles who wish to better understand the unique advantages of bio-based materials, and researchers studying R&D of biobased polyurethanes or remediation of microplastics pollution on land and in bodies of fresh and saltwater worldwide. Builds on the foundation of sustainable, renewable, biodegradable, recyclable microplastics, with lifecycle assessment, techno-economic analysis, and the green premium Clarifies the true economics—if we were to go back to initial development of the plastics industry, what would we do differently? Covers the basic science—the knowledge required to effectively communicate the use of materials that are on first examination more expensive, but on closer examination less expensive when environmental consequences are factored

The enormous production and consumption of fossil-based plastics has caused severe environmental challenges such as pollution of the ocean, increased CO2-emissions, and various health problems. Many of these concerns are intimately connected to the use of fossil fuels in the production of polymers. For this reason, there is a considerable interest to develop bio-based monomers to mitigate some of the issues connected to fossil-based plastics. However, new bio-based monomers are often expensive and need some material advantages to facilitate their market entry. In this context, we have designed several new monomers by converting bio-based molecules such as 5-chloromethylfurfural (CMF), 5-hydroxymethylfurfural (HMF) and vanillin into rigid diols for polyester and polyurethane synthesis. This thesis has been divided into 5 chapters describing the most important findings from each underlying project. In Chapter 1 and 2, HMF was reacted with pentaerythritol and di(trimethylolpropane) to make two rigid diols with cyclic acetal structures. The monomer made from HMF and pentaerythritol was predicted to have an exceptionally low carbon footprint according to our LCA calculations. These diols were further used to synthesize a series of polyesters and polyurethanes with increased glass transition temperatures. Polyurethane synthesis was deemed more suitable for this type of monomers, since degradation occurred at the high temperatures required for polyester synthesis. The obtained polyurethanes were used to prepare coatings and textile fibers. Furthermore, the cyclic acetal structure of the monomers enabled chemical recycling under acidic conditions. In Chapter 3, HMF was produced in a continuous process from fructose, using water and dimethylcarbonate (DMC) in a biphasic system. Both yield and conversion were excellent, demonstrating the utility of DMC for HMF synthesis. The HMF synthesized by this method was sufficiently pure for preparation of the monomers in Chapters 1 and 2 in comparable yields to commercial HMF. In Chapter 4, three rigid diols were prepared from CMF and various lignin-based monomeric aldehydes including 4-hydroxybenzaldehyde, vanillin and syringaldehyde. The diol made from vanillin and CMF was used to prepare a series of thermoplastic polyurethanes with increased glass transition temperatures. The polymers were then cross-linked with DielsAlder chemistry, which could be reversed at higher temperature. This may facilitate its reprocessing and recycling. In Chapter 5, two rigid monomers were produced from potentially lignin-derived phenols, and used to prepare a series of polyesters with tunable thermal properties. The polymers could potentially be chemically recycled by acid hydrolysis.

Understanding variables that affect production of unsaturated polyester polyols based on dimer fatty acids Unidyme(r)14 and Unidyme(r)18 with ethylene glycol and 1,4-butane diol that were synthesized via the polycondensation reaction mechanism. We studied a fast way to determine molecular weight, which usually takes a lot of time and is not very economical and ecological. Among the experimental controlled parameters for each polyol synthesis a special attention was paid to these products viscosity, color, molecular weight, acid and hydroxyl value parameters of extremely commercial importance. The Unidyme(r)14 dimer fatty acid, having a dimer acid percentage of 94%, induces the polyols based on them to be products of relatively commercial relevance. As for the Unidyme(r) 18 dimmer fatty acid, its dimer percentage is 81,8%. Unidyme(r)18 its based polyols commercial interest is specially relevant not only when a lower cost is a relevant factor, but also when its trimmer content is important to confer non-crystallinity properties to the final end product. Also, flexible polyurethane foams were developed (1250-2000 molecular weight) polyol polyester and tested regarding oil absorption capac

An investigation of the extensional mechanical properties of a polyester based polyurethane and a polyether based polyurethane is described. Dynamic steady-state tests were performed over a frequency range of 1000 to 8000 cps and a temperature range of 50 to 110F for the polyester material held at a constant elongation of 105%. The experiments on the polyether were conducted at 110% initial elongation over a range of frequency of 200 to 1600 cps, and a temperature range of 50 to 110F. The complex modulus is found for both materials and the reduced variable concept applied. Master curves for the moduli are determined for a reference temperature of 510R (50F). Relaxation tests were performed on the same materials and the relaxation modulus determined. The relaxation spectrum is determined by using the data from the dynamic and relaxation experiments. (Author).

This is the first volume in the highly regarded Advances in Urethane Science and Technology series to be published by Rapra. This book presents reports on state of the art developments in the field of urethane science, written by experts in their field. The reports in this book are highly technical with an emphasis on industrial applications. This book will be invaluable to researchers and anyone involved with producing or using urethanes.

A variety of methods were used to obtain information about the structural organization and transitions in several polyester and polyether type polyurethanes in order to gain a better understanding of the factors which control the mechanical behavior and water vapor transmission of this important class of polymers. Thermal scanning methods reveal three characteristic transitions which are common to all samples. The low temperature transition is the major glass transition. An intermediate transition in the range of 60-80C is ascribed to urethane to polyester or polyether hydrogen bonding while the highest transition at 130-150C is attributed to interurethane bonding. A transition at 205C, which occurs only in the polyether samples, coincides with the melting of birefringent regions and is believed due to urethane crystallites. Light scattering measurements on this turbid sample indicate the existence of a wide range of structural order. Although crystallinity is absent in the unoriented samples, there is x-ray evidence of the stress induced crystallization of polyether or polyester segments. It is concluded that segregation of prepolymer and urethane segments into domain-like structure occurs in both types of polymers, but to a higher degree in the polyether than in the polyester based polymers, possibly due to restrictions in the latter imposed by interactions of the urethane and ester groups. (Author).

A comprehensive overview of biodegradable polymers, covering everything from synthesis, characterization, and degradation mechanisms while also introducing useful applications, such as drug delivery systems and biomaterial-based regenerative therapies. An introductory section deals with such fundamentals as basic chemical reactions during degradation, the complexity of biological environments and experimental methods for monitoring degradation processes. The result is a reliable reference source for those wanting to learn more about this important class of polymer materials, as well as scientists in the field seeking a deeper insight.