Physical Sciences and Mathematics Commons^™

Enhanced Mechanical Strength Of Soybean Oil-Based Non-Isocyanate Polyurethane Adhesive For Wood Application By Introducing Nanofillers, Vatsal Chaudhari

Electronic Theses & Dissertations

Polyurethane (PU) is a versatile material that finds extensive use in various industries including bedding, construction, automotive, and packaging. Historically, this particular polymer relied significantly on petrochemical resources, a practice that was considered to have negative environmental impacts. The conventional method for preparing PU involves the use of isocyanate, which is a disadvantage due to its negative impact on the environment and human health. The resolution of this problem entails identifying an appropriate substitute for petroleum-derived products that minimize their impact on both the environment and human health. The researchers earlier utilized soybean oil, for the formulation of PUs in …

Exploring Soybean Oil-Based Polyol And Effect Of Non-Halogenated Flame Retardants In Rigid Polyurethane Foam, Sahithi Kondaveeti

Electronic Theses & Dissertations

To address the increasing demand for sustainable biomaterials due to the depletion of fossil fuel resources and growing environmental concerns, a new type of biodegradable and environmentally friendly rigid polyurethane foam (RPUF) has been synthesized. These foams are derived from chemically modified soybean oil-based polyol obtained from soybean oil by epoxidation followed by a ring-opening reaction. Polyurethane foam is generally used in construction, furniture, and automobile industries but is highly flammable and releases toxic gases and smoke during combustion. In this study, a highly efficient synergistic effect halogen-free flame-retardant (FR) melamine salt, 2-carboxyethyl(phenyl)phosphinic acid melamine salt (CMA) was synthesized from …

Effect Of Graphene-Based Fillers On The Properties Of Sunflower-Based Polyurethane, Vishwa Suthar

Electronic Theses & Dissertations

Polyurethane market majorly depends on synthetic materials which are noxious. This stimulated an idea to replace petrochemical resources with renewable resources for polyurethane production. Keeping this in mind, this research focused on the use of sunflower oil for the preparation of polyol and its use in polyurethane composition. The reaction mechanism of epoxidation and ring-opening was approached for the conversion of sunflower oil to polyol. During the conversion of sunflower oil, unsaturated groups of sunflower oil were converted into hydroxyl groups of polyol.

Sunflower oil-based polyol was successfully blended with methylene diphenyl diisocyanate (MDI) to form urethane bonds. Confirmative tests …

Sunflower Oil-Based Polyol In Flame-Retardant Rigid Polyurethane Foams, Magdalene Asare

Electronic Theses & Dissertations

The current shift from solely depending on petroleum sources to seeking renewable alternatives is due to their fast depletion, spike in prices, and the need to reduce our carbon footprint. For instance, the polyurethane industry currently calls for renewable and less toxic polyols and isocyanates for their synthesis over the traditionally used ones. To tackle an aspect of this matter, this work investigates the generation of polyol from sunflower oil, and further probes their use in rigid foams, one of the widely utilized polyurethanes. Epoxidation and ring-opening reactions were used to convert the sunflower oil into a more reactive form, …

Studies In The Use Of 1,1'-Di(1-Hydroxyethyl)Ferrocene As A Flame Retardant For Polyurethanes, Chanel Yeary

Electronic Theses & Dissertations

Significant research in non-toxic flame retardants (FR) has been performed in recent years since the dangerous consequences of halogenated FR were found. As early as the 1970’s, carcinogenic the side effects of halogenated compounds were being acknowledged. Since the early 2000’s halogenated FRs began being phased out of use due to these negative side effects. Since then, significant research has been exploring alternative effective flame retardants. Ferrocene (Fc) is a promising alternative to halogenated FRs due to its nontoxicity and FR properties. This research will report on the synthesis of 1,1’-di(1-hydoxyethyl) ferrocene (DHEFc) and its incorporation into a polyurethane. A …

Environment-Friendly Flame Retardants For Bio-Based Polyurethanes, Felipe Martins De Souza

Electronic Theses & Dissertations

Finding alternative ways to decrease the large consumption of non-renewable resources has been one of the greatest challenges faced by the industry and academia. The trend of using bio-renewable-based materials is an interesting alternative to tackle environmental issues as well as provide economically viable materials. In this work, carvone, an essential oil, was used to synthesize a bio-based polyol through a thiol-ene reaction. The chemical functions were analyzed through Fourier transformed infrared spectrum (FTIR), gel permeation chromatography (GPC), viscosity, and hydroxyl number, which confirmed the synthesis of carvone-based polyol. The latter was then physically blended with three different flame-retardants separately: …

Uv-Curable Organic-Inorganic Hybrid Polyurethane Coating, Shiyin Yu

Master's Theses and Doctoral Dissertations

This thesis explored a series of organic-inorganic hybrid polyurethane oligomers with varying molecular weights and functional groups (acrylate and/or silane) that were cured with a single ultraviolet (UV) trigger but two photo-initiators. Upon UV irradiation, the free-radical initiator initiated a free-radical reaction for acrylate cross-linking, and the photo-latent base initiated a sol-gel reaction for condensation of the silanes. This study explored the cure extent of both reactions by FTIR for acrylates and silanes and a weight-loss method for silanes as a function of functional group concentration and time. The general film properties were also studied. The results showed that the …

Nanomorphology Dependent Optical And Mechanical Properties Of Aerogels, Chandana Mandal

Doctoral Dissertations

"Aerogels are very low density, light weight open pore materials. A hypothesis that is under intense current investigation by the scientific community states that the mechanical properties of nanostructured polymers depend on their nanomorphology. Aerogels are nanostructured ultra-lightweight nanoporous materials with skeletal frameworks that can display a wide range of nanomorphologies. Thereby aerogels comprise a suitable platform for testing not only that hypothesis but also a wide range of other properties such as light scattering for applications, for example, in thermally insulating windows.

To study the mechanical properties of nanostructured matter as a function of nanomorphology, various shape-memory polyurethane aerogels …

A Detailed Study Of Novel High-Performance Bromine And Phosphorus Based Reactive Flame Retardants In High-Quality Bio-Polyol Based Rigid Polyurethane Foams, Sanket Bhoyate

Electronic Theses & Dissertations

Structural fire is one of the most catastrophic issues related to human safety observed from reports of National Fire Protection Association of United States in past years. Polyurethanes are one of the important structural material used as thermal insulation in housing. They are also used in automotive, construction, medical, packaging, furniture, thermal, electrical, and vibration insulation. Considering this, we have synthesized bio-based polyurethane foams using limonene-based polyol, isocyanates, and other compounds. Flame retardancy was imparted using reactive flame retardant polyols. Firstly, flame retardancy test was performed on the foams using two novel aliphatic and two novel aromatic bromine-based synthesized reactive …

The Effect Of Plant Source On Lignin-Based Polyurethanes And The Interdiffusion Dynamics Of Semi-Rigid Polymers, Jason Michael Lang

Masters Theses

The work reported in this thesis increases our understanding of the effect of lignin plant source on the mechanical and morphological properties of lignin-based polyurethanes and the interdiffusion of glassy/liquid bilayer thin films. The interdiffusion of glassy/liquid polymer pairs has received much less attention than liquid/liquid bilayers, leading to conflicting results and unresolved discrepancies. Therefore, the reported study of interdiffusion between polysulfone glassy/liquid polymer layers provides insight into the dynamics of these systems.

This thesis first reports the correlation between the mechanical properties of lignin-based polyurethanes and the lignin plant source. Lignin is a molecule that can be used as …

Use Of Decahydrodecaborate As Flame Retardants In Polyurethanes, Austin W. Bailey

Electronic Theses & Dissertations

There is a growing need for non-halogenated flame retardants due to the toxicity and environmental impacts that are exhibited by current ones. The polyurethane industry is one that has expressed a need for flame retardants in many of its industrial and commercial applications. For these reasons, two different decaborate compounds, tetramethyl and tetrabutyl ammonium decahydrodecaborate, were synthesized and incorporated into polyurethane films for testing. The compounds were characterized using Fourier Transform Infrared (FT-IR) spectroscopy, Proton-Nuclear Magnetic Resonance (¹H-NMR) spectroscopy, Carbon-Nuclear Magnetic Resonance (¹³C-NMR) spectroscopy, and Boron-Nuclear Magnetic Resonance (¹¹B-NMR) spectroscopy. The compounds were incorporated …

Biowaste Derived Rigid Polyurethane Foams And Supercapacitors: A Renewable And Sustainable Alternative For Petrochemicals, Charith K. R. Akurana Gamaralalage

Electronic Theses & Dissertations

Bio-based polyol for rigid polyurethane (PU) foams and porous structured carbon as an electrode material for supercapacitors were synthesized from readily available biowaste precursor (orange peel) as an alternative to currently used petroleum-based starting materials. Synthesized bio-based polyols were characterized using FTIR, GPC, hydroxyl number, and viscosity measurements. These analyses indicated that intended bio-based polyol was obtained via thiol-ene chemistry with a high yield. Rigid PU foams prepared from bio-based polyol exhibited density around 35 kg/m³, maintained a regular cell structure with uniform cell distribution, closed cell content over 90%, and excellent compressive strength of ~230 kPa, suggesting …

Molecular Interpretation Of A Trigger For Controlling An Amine Isocyanate Polyurethane Reaction, Katherine V. Carrasquillo

Masters Theses

The temperature profile needed to complete the reaction between the sodium-diamine complex and the isocyanate terminated prepolymer has been established. The sodium diamine complex has the advantage of blocking the nearly instantaneous reaction between the diamine and isocyanate from taking place until it is released at elevated temperatures. Because of its low melting temperature (~40 °C) and its low molecular weight (low viscosity), this chain extension reaction is not dependent on the participation of the prepolymer. Instead, the rate of reaction is dependent on the dissolution of the 4,4’-methylenedianiline (MDA) complex into the system. The dissolution of the MDA complex …

Synthesis Of Polyhedral Oligomeric Silsesquioxane (Poss) Functionalized Carbon Nanotubes For Improved Dispersion In Polyurethane Films, Xiaonan Kou

Dissertations

Carbon nanotube (CNT) polymer nanocomposites are promising advanced materials. These materials exhibit the advantages of traditional polymeric materials, such as being light weight and easy to process, combined with the potential to exhibit enhanced mechanical, thermal and electrical properties compared to pure polymers. To achieve substantial improvement of composite properties at low CNT loading, uniform dispersion of CNTs in the polymer matrix and strong CNT-polymer interfacial interaction are needed. However, it is difficult to achieve adequate dispersion and interfacial interactions due to the inert nature of CNTs. In this project, polyhedral oligomeric silsequioxane (POSS) will be used as a dispersing …

Self-Repairable Polymeric Networks: Synthesis And Network Design, Biswajit Ghosh

Dissertations

This dissertation describes the design, synthesis and development of a new class of polymeric networks that exhibit self-repairing properties under UV exposure. It consists of two parts: (a) modification and synthesis of oxetane (OXE), and oxolane (OXO) substituted chitosan (CHI) macromonomer, and (b) design, and synthesis of self-repairing polyurethane (PUR) networks consisting of modified chitosan. Unmodified CHI consisting of acetamide (-NHCOCH₃), primary hydroxyl (-OH), and amine (-NH₂) functional groups were reacted with OXE or OXO compounds under basic conditions in order to substitute the 1° –OH groups, and at the same time, convert -NHCOCH₃ functionalities …

Development And Extrapolation Of An Undergraduate Laboratory Experiment To An Elastomeric Spinal Muscular Atrophy Brace, Richard Sterling Brose

Master's Theses

Ever since the advent of polymer science, polyurethanes have played a huge role in the industrial world. They have been used in endless applications from furniture padding to aircraft coatings, to binders for insensitive munitions. It is therefore important that the chemistry of polyurethanes is well understood as well as the ability to draw relationships between the raw materials selected and the end-use properties of the polymer. Because of the multitude of practical applications, the development of an undergraduate polymer chemistry laboratory focused on polyurethane elastomers is developed and described herein. Polymer chemistry students are exposed to hydroxyterminated polybutadiene (HTPB) …