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Aminolysis of PET using Ethylene Glycol Catalyst and Long Chain Alkyl-Amines

Description
Various research papers and literature were reviewed and consulted for the depolymerization of polyethylene terephthalate (PET) using long chain alkyl amines and ethylene glycol (EG) as catalyst in the aminolysis process. The main hypothesis of this thesis is to use EG as a catalyst in the aminolysis of PET using…

Various research papers and literature were reviewed and consulted for the depolymerization of polyethylene terephthalate (PET) using long chain alkyl amines and ethylene glycol (EG) as catalyst in the aminolysis process. The main hypothesis of this thesis is to use EG as a catalyst in the aminolysis of PET using octylamine, dodecylamine and hexadecylamine. Initial reactions with the three amines were performed with and without EG to observe and compare the terephthalamides obtained from these reactions to test this hypothesis. Various reaction conditions like concentration of reactants, temperature and time of reaction were later considered and employed to find the optimal conditions for the depolymerization of PET before confirming the catalytic properties of EG in the aminolysis reaction. The depolymerized products were subjected to attenuated total reflectance-infrared spectroscopy (ATR-IR Spectroscopy) to check for presence of important amide and ester peaks through their infrared absorption peaks, thermogravimetric analysis (TGA) to find their Td5 temperatures and differential scanning calorimetry (DSC) to check for endothermic melting temperature of the obtained products. These characterization techniques were used to understand, examine, and compare the different properties of the products obtained from different reaction mixtures. The three distinct amines considered for this reaction also showed differences in the conversion rate of PET under similar reaction conditions thus signifying the importance of selecting an appropriate amine reactant for the aminolysis process. Finally, the in-situ IR probe was used to determine the reaction kinetics of the aminolysis reaction and the formation and loss of products and reactants with time.
ContributorsBakkireddy, Adarsh (Author) / Green, Matthew (Thesis advisor) / Emady, Heather (Committee member) / Seo, Eileen S. (Committee member) / Arizona State University (Publisher)
Created2023
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Recycling of HDPE

Description
High-Density polyethylene (HDPE) is the most used polymer on earth. Since it is used in such large quantities, it has become the most extensively produced polymer on the planet. Unfortunately, the rate of reusing or recycling HDPE is far behind the rate of production leading to plastic pollution. Most of…

High-Density polyethylene (HDPE) is the most used polymer on earth. Since it is used in such large quantities, it has become the most extensively produced polymer on the planet. Unfortunately, the rate of reusing or recycling HDPE is far behind the rate of production leading to plastic pollution. Most of this waste plastic ends up in landfills or incineration to recover energy. Plastic production consumes a lot of energy and is associated with CO2 emissions. This method of disposing plastic only adds to the environmental pollution rather than improving it. Primary reasons for low recycling rate appear to be more political and financial. In the US, the rate of recycling was less than 10% whereas Japan showed a recycling rate of more than 80%. The other aspect of low recycling is financial. In order to make recycling a financially viable process, efforts have to be made to streamline the process of waste collection, segregation and technically feasible process. This study focusses on the technical aspect of the issue. Even though efforts have been made to recycle HDPE, none of the processes have been recycle HDPE with financial viability, recovering full value of plastic, minimum CO2 emissions and minimum change in properties of the polymer. This study focusses on effective recycling of HDPE with minimum change in its properties. Dissolution has been used to dissolve the polymer selectively and then reprecipitating the polymer using a non-solvent to obtain the polymer grains. This is followed by mixing additives to the polymer grains to minimize degradation of the polymer during the extrusion process. The polymer is then extruded in an extruder beyond its melting temperature. This process is repeated for 5 cycles. After each cycle, the polymer is tested for its properties using the Tensile Testing, Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and Dynamic Mechanicalii Analysis (DMA). It was observed that the rheological properties of the polymer were maintained after the 5th recycle whereas the mechanical properties deteriorated after the 2nd recycle. Also, increase in carbonyl index was observed after 5th recycle.
ContributorsSaini, Rahul Rakesh (Author) / Green, Matthew (Thesis advisor) / Holloway, Julianne (Committee member) / Xie, Renxuan (Committee member) / Arizona State University (Publisher)
Created2022
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Utilization of thermoplastic mounting studs for simple performance testing on hot mix asphalt

Description

The objective of the research is to test the use of 3D printed thermoplastic to produce fixtures which affix instrumentation to asphalt concrete samples used for Simple Performance Testing (SPT). The testing is done as part of materials characterization to obtain properties that will help in future pavement designs. Currently,…

The objective of the research is to test the use of 3D printed thermoplastic to produce fixtures which affix instrumentation to asphalt concrete samples used for Simple Performance Testing (SPT). The testing is done as part of materials characterization to obtain properties that will help in future pavement designs. Currently, these fixtures (mounting studs) are made of expensive brass and cumbersome to clean with or without chemicals.

Three types of thermoplastics were utilized to assess the effect of temperature and applied stress on the performance of the 3D printed studs. Asphalt concrete samples fitted with thermoplastic studs were tested according to AASHTO & ASTM standards. The thermoplastics tested are: Polylactic acid (PLA), the most common 3D printing material; Acrylonitrile Butadiene Styrene (ABS), a typical 3D printing material which is less rigid than PLA and has a higher melting temperature; Polycarbonate (PC), a strong, high temperature 3D printing material.

A high traffic volume Marshal mix design from the City of Phoenix was obtained and adapted to a Superpave mix design methodology. The mix design is dense-graded with nominal maximum aggregate size of ¾” inch and a PG 70-10 binder. Samples were fabricated and the following tests were performed: Dynamic Modulus |E*| conducted at five temperatures and six frequencies; Flow Number conducted at a high temperature of 50°C, and axial cyclic fatigue test at a moderate temperature of 18°C.

The results from SPT for each 3D printed material were compared to results using brass mounting studs. Validation or rejection of the concept was determined from statistical analysis on the mean and variance of collected SPT test data.

The concept of using 3D printed thermoplastic for mounting stud fabrication is a promising option; however, the concept should be verified with more extensive research using a variety of asphalt mixes and operators to ensure no bias in the repeatability and reproducibility of test results. The Polycarbonate (PC) had a stronger layer bonding than ABS and PLA while printing. It was recommended for follow up studies.
ContributorsBeGell, Dirk (Author) / Kaloush, Kamil (Thesis advisor) / Mamlouk, Michael (Committee member) / Stempihar, Jeffery (Committee member) / Arizona State University (Publisher)
Created2018

A study of heating and degradation of acrylonitrile-butadiene-styrene/polycarbonate polymer due to ultraviolet lasers illumination during localized pre-deposition heating for fused filament fabrication 3D printing

Description
With the growing popularity of 3d printing in recreational, research, and commercial enterprises new techniques and processes are being developed to improve the quality of parts created. Even so, the anisotropic properties is still a major hindrance of parts manufactured in this method. The goal is to produce parts that…

With the growing popularity of 3d printing in recreational, research, and commercial enterprises new techniques and processes are being developed to improve the quality of parts created. Even so, the anisotropic properties is still a major hindrance of parts manufactured in this method. The goal is to produce parts that mimic the strength characteristics of a comparable part of the same design and materials created using injection molding. In achieving this goal the production cost can be reduced by eliminating the initial investment needed for the creation of expensive tooling. This initial investment reduction will allow for a wider variant of products in smaller batch runs to be made available. This thesis implements the use of ultraviolet (UV) illumination for an in-process laser local pre-deposition heating (LLPH). By comparing samples with and without the LLPH process it is determined that applied energy that is absorbed by the polymer is converted to an increase in the interlayer temperature, and resulting in an observed increase in tensile strength over the baseline test samples. The increase in interlayer bonding thus can be considered the dominating factor over polymer degradation.
ContributorsKusel, Scott Daniel (Author) / Hsu, Keng (Thesis advisor) / Sodemann, Angela (Committee member) / Kannan, Arunachala M (Committee member) / Arizona State University (Publisher)
Created2017