Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Heterophasic ethylene-propylene copolymers, also known as impact polypropylene (PP) copolymers (IPCs) or heterophasic copolymers (HECOs), are a unique group of polyolefins produced through the copolymerisation of ethylene and propylene, with the aim of improving the impact properties of the PP homopolymer at low temperatures. Therefore, this polymer comprises of a PP homopolymer matrix with a dispersed rubbery copolymer phase. Due to their unique properties, HECO polymers have become commercially important materials, with a wide range of applications. Therefore a fundamental understanding of the processes and chemistry that affects their final macroscopic properties needs to be expanded. The main focus of this investigation was to understand why specific organic peroxides influence or interact differently with the various phases of HECO polymers, in order to utilize their properties to obtain HECO polymers with optimal and desired properties. Two HECO polymers with different ethylene contents were fractionated into three fractions (30, 100 and 130 °C), using preparative temperature rising elution fractionation (P-TREF). Each individual TREF fraction was degraded with two different types of organic peroxides, and then characterised using four different analytical tools. The changes in the molecular structures of the different fractions were investigated by Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The changes in comonomer sequence distributions were investigated by carbon 13 nuclear magnetic resonance spectroscopy (13C-NMR). Moreover, the degradation of the different fractions was investigated by high temperature size exclusion chromatography (HT-SEC). The investigation showed that the HECO polymers with different ethylene contents were uniquely altered. It was evident that the ethylene content influenced the degradation behaviour of the HECO polymers. The ability of the peroxide to affect certain regions of the HECO polymer more than others is highly dependent upon its miscibility with certain regions of the HECO polymers. The “visbreaking” efficiency of a specific organic peroxide appears to be primarily dependent on the number of “peroxy” groups it contains in its molecular structure. Stellenbosch University https://scholar.sun.ac.za / AFRIKAANSE OPSOMMING: Heterofase etileen-propileen ko-polimere, ook bekend as impak PP ko-polimere (IPCS) of heterofase ko-polimere (HECO), is 'n unieke groep poliolefiene geproduseer deur die ko-polimerisasie van etileen en propileen, met die doel op die verbetering in die impak eienskappe van die PP homopolimeer by lae temperature. Hierdie polimeer bestaan dus uit 'n PP homopolimeer matriks met 'n verspreide rubberagtige ko-polimeer fase. As gevolg van hul unieke eienskappe, is HECO polimere van kommersiële belang, met 'n wye verskeidenheid van toepassings. 'n Fundamentele begrip van die prosesse en chemie wat die finale makroskopiese eienskappe beïnvloed moet dus uitgebrei word. Die hooffokus van hierdie ondersoek was om te verstaan waarom spesifieke organiese peroksiede verskillende invloede en interaksies met die verskillende fases van HECO polimere het, om sodoende van hul eienskappe gebruik te maak om HECO polimere te verkry met optimale en gewenste eienskappe. Twee HECO polimere met verskillende etileen inhoud was gefraksioneer in drie fraksies (30, 100 en 130 °C), met behulp van preparatiewe temperatuur styging eluering fraksionering (P-TREF). Elke individuele TREF fraksie was gedegradeer met twee verskillende tipes organiese peroksiede en daarna gekarakteriseer deur vier verskillende analitiese metodes. Die veranderinge in molekulêre strukture van die verskillende fraksies was geondersoek met behulp van Fourier transform infrarooi spektroskopie (FTIR) en differensiële skandering kalorimetrie (DSC). Die veranderinge in ko-monomeer volgorde distribusie was bestudeer deur middel van kern magnetiese resonans spektroskopie (KMR). Verder was die degradasie van die verskillende fraksies met behulp van hoë temperatuur grootte uitsluitingschromatografie (HT-SEC) bestudeer. Die ondersoek het getoon dat die HECO polimere met verskillende etileen inhoud uniek gedegradeer was. Dus is dit duidelik genoeg dat die etileen inhoud die degradasie gedrag van die HECO polimere beïnvloed het. Die vermoë van die peroksied om sekere areas van die HECO polimeer meer as ander te beïnvloed is hoogs afhanklik van die mengbaarheid met sekere areas van die HECO polimere. Die "visbreking" doeltreffendheid van 'n spesifieke organiese peroksiede is meestal afhanklik van die aantal "peroksie" groepe in die molekulêre struktuur.

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Die vorliegende Arbeit beschreibt die Herstellung und Charakterisierung der ersten Antikörper gegen Triacetontriperoxid (TATP), einem hoch empfindlichen und unkonventionellen (nicht-kommerziellen) Initialsprengstoff. Entscheidend dafür war die Synthese eines TATP-imitierenden Haptens, welches die typische nonagonale Struktur des TATP mit seinen drei Peroxid- und sechs Methylgruppen nahezu perfekt nachbildet, aber den Vorzug einer zusätzlichen Carboxygruppe zur kovalenten Kopplung an Proteine aufweist. Dadurch konnte das TATP-Hapten an Rinderserumalbumin (BSA) gebunden werden, um ein immunogenes Konjugat zu erzeugen, welches die erfolgreiche Immunisierung zweier Säugetierarten, Maus und Kaninchen, ermöglichte. Der Verlauf der In vivo-Immunisierungen wurde durch die Analyse der Tierseren in regelmäßigen Abständen mittels enzymgekoppeltem Immunoassay (ELISA) verfolgt. Die polyklonalen Antikörper beider Spezies waren ungewöhnlich selektiv gegenüber TATP. Jedoch unterschied sich die Affinität der Antikörper der zwei Spezies um das 5000-fache, wobei die Kaninchenseren den Mausseren überlegen waren. Entsprechend war auch die mit Kaninchenserum erreichbare TATP-Nachweisgrenze von 0.01 µg/L deutlich besser im Vergleich zu 50 µg/L, die mit Mausserum erzielt wurden. Der Messbereich des TATP-ELISA mit Kaninchenserum deckte zudem mehr als vier Zehnerpotenzen ab, wie mittels Präzisionsprofil bestimmt wurde. Die erhaltenen TATP-Antikörper aus Kaninchen stehen damit Anwendungen in Nachweissystemen für die sehr empfindliche Detektion von TATP zur Verfügung, die u. a. in sicherheitsrelevanten Bereichen zum Einsatz kommen könnten. Als erste Anwendung wurde ein TATP-ELISA realisiert, der im Rahmen dieser Arbeit ausführlich optimiert wurde. Außerdem wurden erste Schritte zur Entwicklung eines TATP-Schnelltests (LFA) unternommen. Weitere Biosensoren auf Grundlage der neu entwickelten TATP-Antikörper sind denkbar. / The present work decribes the production and characterization of the first antibodies against triacetone triperoxide (TATP), a highly sensitive and improvised (non-commercial) primary explosive. Crucial to this work was the synthesis of a TATP-related hapten that mimics almost perfectly the typical nonagonal structure of TATP with its three peroxide and six methyl groups. Advantageously, it has an additional carboxylic acid group, which provides a conjugation site for covalent attachment to proteins. Thus, the TATP hapten could be linked to bovine serum albumin (BSA) to produce an immunogenic conjugate, allowing the successful immunization of two different mammalian species, mouse and rabbit. The in vivo immunization progress was followed by periodically analyzing the animals’ sera using enzyme-linked immunosorbent assay (ELISA). The polyclonal antibodies of both species were remarkably selective to TATP. The affinity of these TATP-antibodies was, however, different between the two species, with the rabbit sera showing an affinity about 5000-fold superior than the murine one. Consequently, the TATP detection limit of 0.01 µg/L was considerably better using the sera from rabbit in contrast to 50 µg/L when mouse serum was used. The working range of the TATP-ELISA with rabbit sera covers more than four decades, calculated from a precision profile. The obtained TATP antibodies from rabbit are now available for applications in highly sensitive detection systems for TATP, which could be employed, among others, in security-relevant areas. The first application was the realization of a TATP-ELISA, which was extensively optimized within the course of this work. Furthermore, the first steps towards the development of a lateral flow assay (LFA) targeting TATP were taken, making conceivable further biosensor platforms based on the newly developed TATP antibodies.