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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Mechanical testing and biodegradation of an alternative dibenzoate plasticizer

Firlotte, Nicolas. January 2008 (has links)
Plasticizers are ubiquitous environmental contaminants. Biodegradation of some of these chemicals, such as di(2-ethylhexyl) phthalate (DEHP or DOP), has been shown to lead to the accumulation of toxic metabolic breakdown products. As a result there is a desire to produce new, fully biodegradable, "green" plasticizers. With this goal in mind, a series of tests were developed to be used to measure the plasticizing efficiency of potential green plasticizers. The base resin selected for the study was poly(vinyl chloride) (PVC). The glass transition temperature (Tg) of the plasticized polymer was measured by temperature-modulated differential scanning calorimetry (TMDSC). Tensile tests were carried out on samples of the material from which the tensile strength and the strain at break of the material were measured. The aforementionned properties were measured for PVC plasticized with the commercial plasticizers DEHP, diethylene glycol dibenzoate (DEGDB) and dipropylene glycol dibenzoate (DPGDB) at several plasticizer concentrations. / 1,5 pentanediol dibenzoate (PDDB) was synthesized and evaluated as a plasticizer by comparing results for this compound with those for the commercial plasticizers using the developed tests. The depression in Tg and tensile properties were comparable at a fixed composition for blends with PDDB relative to blends with DEHP, DEGDB, and DPGDB. PDDB was subjected to biodegradation unsing co-metabolism by the common soil bacterium Rhodococcus rhodocrous (ATCC 13808). After 16 days of growth, nearly all the PDDB was degraded and only small amounts of transient, unidentified, metabolites were observed in the growth medium during the experiment.
2

Mechanical testing and biodegradation of an alternative dibenzoate plasticizer

Firlotte, Nicolas. January 2008 (has links)
No description available.
3

The synthesis and characterization of novel materials for use in secondary lithium-ion batteries

Nafshun, Richard L. 09 August 1996 (has links)
Graduation date: 1997
4

The distribution and behaviour of phthalate esters in the aquatic environment

Al-Omran, L. A. J. January 1987 (has links)
No description available.
5

Pharmacokinetics, cerebrovascular permeability & biotransformation of the neurotoxic plasticiser N-butylbenzenesulfonamide (NBBS) /

Samiayah, Ganesh Kumar. January 1997 (has links)
Thesis (Ph. D.)--University of New South Wales, 1997. / Also available online.
6

Mobility and oxidative stability in plasticised food matrices : the role of water /

Partanen, Riitta. January 1900 (has links) (PDF)
Thesis (doctoral)--Helsinki University of Technology, 2008. / Includes bibliographical references. Also available on the World Wide Web.
7

Evaluation of eucalyptus citriodora derived p-menthane-3,8-diol-citronellal acetal as a bio-plasticizer for cosmetic application

Burger, Kirstin January 2013 (has links)
Plasticizers are generally added to cosmetic and personal care products to improve the filmforming abilities of the product and increase flexibility of the film formed on the skin or hair surface. For example, plasticizers are present in perfumes to prolong the release of the specific scent, which is the ultimate goal in a good quality perfume. Plasticizers in nail varnishes prevent chipping, improve the aesthetics by adhering to the keratin in the nail which means the coating stays on for much longer, which is the ultimate goal in nail products. Plasticizers improve the gloss, resist chipping and allow quick drying time. Therefore it can be seen that plasticizers play a vital role in personal care products like perfumes and nail varnishes. Certain plasticizers e.g. phthalates, can cause problems associated with human health and can harm the environment. They are easily available and large volumes can be obtained at a low cost. These phthalates, for example, di-butyl phthalate (DBP) have been identified as carcinogenic. Nowadays the occurrence of cancer is rapidly increasing. The plasticizers present in a large number of consumer and personal care products, can possibly be linked to the ever increasing reports of cancer. Therefore a substitute to the traditional phthalate plasticizers must be investigated. The aim of this research is to produce a plasticizer derived from naturally occurring Eucalyptus oil, which can be used to replace the existing plasticizers in cosmetic formulations. Para-menthane-3,8-diol (PMD), occurring naturally in the oil from the tree, Eucalyptus citriodora, forms an acetal with citronellal (PMD, acetal, citronellal all occur naturally in the oil). It has been previously shown that PMD-citronellal acetal will exhibit plasticizing properties similar to conventional plasticizers. The objective was to enhance the formation of the acetal in the Eucalyptus oil by reacting it with excess PMD. An effective synthesis method for the PMD-citronellal acetal enriched oil (~73.8 percent) was determined from optimization experiments. The physical characterisation of the PMD-citronellal acetal enriched oil was done and compared with that of DBP. The acetal-enriched oil had a lower density, slightly higher solubility in water (at 25°C), lower refractive index (Brix percent) and a higher boiling point (350°C) than DBP. The physical characteristics of the Eucalyptus oil source and the acetal-enriched Eucalyptus oil were very similar. This can be expected as the Eucalyptus oil consists of ~84.3 percent Citronellal, ~ 1.3 percent PMD and 2.7 percent PMD-citronellal acetal. In this study the effectiveness of the acetal-enriched Eucalyptus oil (referred to from now on as the bio-plasticizer) was compared to a conventional plasticizer such as di-butyl phthalate (DBP), commonly used in cosmetic products. Two cosmetic formulations were produced: a nail varnish and a perfume formulation. Various tests were performed on these formulations to investigate the plasticizing properties of the bio-plasticizer. The objectives were to determine if the natural plasticizer is as effective as the potentially carcinogenic phthalate plasticizers and can be used as a substitute for the phthalates in personal care products. The results indicate that the bio-plasticizer does behave similarly to di-butyl phthalate, however, the effectiveness of the bio-plasticizer is lower than that of di-butyl phthalate. As the viscosity of the synthesized oil was high, this affected the overall consistency of the products. A more viscous nail varnish and perfume was produced in comparison to the DBP counterpart. The stability of the bio-plasticizer in the cosmetic formulations of nail varnish and perfume was also investigated. The cosmetic products were incubated at 0°C, 25°C and 40°C over a period of two months. Any changes in colour, odour, pH, refractive index, separation and plasticizer peak change in the gas chromatogram trace were recorded. It was determined that the PMD-citronellal acetal-enriched oil was relatively unstable under elevated temperatures and light intensity. Storage under higher temperatures (40°C) tends to increase the acidity. Therefore the bio-plasticizer must be placed in a closed, covered bottle and stored in an environment away from light and elevated temperatures. According to the gas chromatogram peaks, it was clear that both the bio-plasticizer and the DBP were more unstable in the perfume formulation than in the nail polish and were especially sensitive to light when in the perfume. This could possibly be due to the interaction with the fragrance molecule, p-anisaldehyde.
8

A general study of the migration of some contaminants and plasticisers from the packaging materials into food.

January 1995 (has links)
by Wong Siu Kay. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 172-175). / Chapter PARTI : --- Naphthalene contamination in Milk Drinks / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 : --- Methods of determination of Naphthalene in Milk and Packaging Materials --- p.6 / Chapter Chapter 3 : --- Prediction Method I - Simulation --- p.15 / Chapter Chapter 4 : --- Prediction Method II- Mathematical Modelling --- p.24 / Chapter Chapter 5 : --- Atmospheric Effect I - Naphthalene Vapour in Air --- p.31 / Chapter Chapter 6 : --- Atmospheric Effect II- Aromatic Hydrocarbons in Air --- p.44 / Chapter Chapter 7 : --- Naphthalene Contamination In Solid Foods --- p.58 / Chapter Chapter 8 : --- Migration of Naphthalene in other Types of Polymers --- p.69 / Chapter Chapter 9 : --- Further Studies --- p.76 / Reference --- p.31 / Appendix I --- p.88 / Chapter Part II : --- General Study of Plasticisers Migration into Food / Chapter Chapter 1 : --- Introduction --- p.91 / Chapter Chapter 2 : --- Survey of Plasticisers Level in Food Contact Materials --- p.100 / Chapter Chapter 3 : --- Survey of Plasticisers Level in Foodstuff --- p.119 / Chapter Chapter 4 : --- Mathematical Modelling --- p.139 / Chapter Chapter 5 : --- Effect of Microwave Heating --- p.159 / Reference --- p.172 / Appendix II --- p.176
9

Analysis of plasticisers in food by GC/MS.

January 1996 (has links)
by Wai Yin Karen Fong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves [106]-[110]). / Abstract --- p.2 / Acknowledgments --- p.3 / Dedication --- p.4 / Abbreviations --- p.5 / Table of Contents --- p.7 / Chapter Chapter 1: --- Introduction --- p.11 / Chapter 1.1 --- Overviews of packaging materials --- p.11 / Chapter 1.2 --- Source of contamination --- p.14 / Chapter 1.2.1 --- Contamination from packaging materials --- p.15 / Chapter 1.2.2 --- Contamination of plasticisers from packaging materials and its effect --- p.16 / Chapter 1.3 --- Classification of commercial plasticisers --- p.19 / Chapter 1.3.1 --- Application of plasticisers --- p.20 / Chapter 1.4 --- Analysis of the plasticisers in the food packaging films --- p.22 / Chapter 1.5 --- Analysis of plasticisers in food using isotope dilution technique --- p.22 / Chapter Chapter 2 --- : Instrumentation and Analytical methods --- p.25 / Chapter 2.0 --- Instrumentation --- p.25 / Chapter 2.1 --- Gas chromatography --- p.25 / Chapter 2.2 --- Detector --- p.26 / Chapter 2.2.1 --- Flame ionisation detector --- p.26 / Chapter 2.2.2 --- Mass spectrometer --- p.27 / Chapter 2.2.2.1 --- Ion trap detector --- p.28 / Chapter 2.2.3 --- Ionisation mode --- p.33 / Chapter 2.2.3.1 --- Electron ionisation (EI) --- p.33 / Chapter 2.2.3.2 --- Chemical ionisation (CI) --- p.34 / Chapter 2.4 --- Analytical methods --- p.36 / Chapter 2.3 --- The use of combined GC/MS in the analysis of plasticisers --- p.36 / Chapter 2.3.1 --- Identification by GC/MS --- p.37 / Chapter 2.3.2 --- Qualitative MS --- p.37 / Chapter 2.3.3 --- Quantitative MS --- p.39 / Chapter 2.3.3.1 --- Isotope dilution technique --- p.40 / Chapter Chapter 3: --- Analysis of plasticisers in food packaging materials --- p.41 / Chapter 3.1 --- Introduction --- p.41 / Chapter 3.2 --- Experimental and Instrumental --- p.42 / Chapter 3.2.1 --- Reagents --- p.43 / Chapter 3.2.2 --- Materials --- p.43 / Chapter 3.3 --- Identification of food packaging materials --- p.43 / Chapter 3.3.1 --- Fourier transform infrared spectrometry --- p.44 / Chapter 3.3.2 --- Burning test --- p.45 / Chapter 3.3.3 --- Solvent dissolution method --- p.46 / Chapter 3.4 --- Extraction of plasticisers from the packaging materials --- p.49 / Chapter 3.4.1 --- Chloroform extraction --- p.50 / Chapter 3.4.2 --- Solvent reflux method --- p.50 / Chapter 3.5 --- Results and discussion --- p.51 / Chapter 3.5.1 --- Precision test --- p.51 / Chapter 3.5.2 --- Calibration curve --- p.52 / Chapter 3.5.3 --- Detection limit --- p.54 / Chapter 3.5.4 --- Recovery --- p.54 / Chapter 3.6 --- Survey of the level of plasticisers in food packaging materials --- p.55 / Chapter 3.7 --- Conclusion --- p.66 / Chapter 4.0 --- Analysis of plasticisers in foods --- p.67 / Chapter 4.1 --- Introduction --- p.67 / Chapter 4.2 --- Experimental and instrument --- p.67 / Chapter 4.2.1 --- Reagents --- p.68 / Chapter 4.2.2 --- Materials --- p.68 / Chapter 4.3 --- Analysis --- p.69 / Chapter 4.3.1 --- selection of stable isotope labelled analogues --- p.69 / Chapter 4.3.2 --- Synthesis of deuterated internal standard --- p.70 / Chapter 4.4 --- Extraction of foods --- p.71 / Chapter 4.4.1 --- Clean up method --- p.73 / Chapter 4.4.2 --- Quantitation --- p.77 / Chapter 4.5 --- Results and discussion --- p.82 / Chapter 4.5.1 --- Precision test --- p.82 / Chapter 4.5.2 --- Calibration curve --- p.84 / Chapter 4.5.3 --- Detection limit --- p.85 / Chapter 4.5.4 --- Survey of the level of plasticisers in food --- p.86 / Chapter 4.6 --- Conclusion --- p.91 / Chapter 5.0 --- Analysis of plasticisers in food by EI and CI method / Chapter 5.1 --- Introduction --- p.93 / Chapter 5.2 --- Experimental and Instrumental --- p.94 / Chapter 5.2.1 --- Reagents --- p.95 / Chapter 5.2.2 --- Materials --- p.95 / Chapter 5.3 --- Extraction of foods --- p.95 / Chapter 5.3.1 --- Clean up method --- p.95 / Chapter 5.4 --- Result and discussion --- p.95 / Chapter 5.4.1 --- Precision test --- p.95 / Chapter 5.4.2 --- Calibration curve --- p.97 / Chapter 5.4.3 --- Detection limit --- p.99 / Chapter 5.4.4 --- Survey of plasticisers in food by EI and CI method --- p.100 / Chapter 5.4.5 --- Paired t-Test --- p.103 / Chapter 5.5 --- Conclusion --- p.104 / Chapter Chapter 6 --- Conclusion --- p.105 / Bibliography --- p.106 / Appendices : / Chapter 1 --- The mass spectrum of DEP --- p.i / Chapter 2 --- The mass spectrum of DIBA --- p.i / Chapter 3 --- The mass spectrum of DIBP --- p.ii / Chapter 4 --- The mass spectrum of DBP --- p.ii / Chapter 5 --- The mass spectrum of DBS --- p.iii / Chapter 6 --- The mass spectrum of ATBC --- p.iii / Chapter 7 --- The mass spectrum of BBP --- p.iv / Chapter 8 --- The mass spectrum of DEHA --- p.iv / Chapter 9 --- The mass spectrum of DPOP --- p.v / Chapter 10 --- The mass spectrum of DEHP --- p.v / Chapter 11 --- The mass spectrum of DCHP --- p.vi / Chapter 12 --- The mass spectrum of DOAZ --- p.vi / Chapter 13 --- The mass spectrum of DOS --- p.vii / Chapter 14 --- Calibration curve of GC/FID --- p.viii / Chapter 15 --- Calibration curve of GC/MS (magnum) --- p.xi / Chapter 16 --- Calibration curve of GC/MS (GCQ) --- p.xiv
10

Introduction of Natural Oils into Rubber Compounds

Norwood, Verrill M, IV 01 May 2014 (has links)
In the rubber industry, plasticizers for rubber compounds mainly consist of petroleum derivatives. Consequently, the rubber industry is in constant competition with many petroleum consumers. This competition places an economic strain on rubber companies such as HEXPOL RUBBER COMPOUNDING L.L.C. In order to alleviate this strain, natural oil alternatives to petroleum plasticizers are of novel research interest and are investigated in this thesis project.

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