The grafting and chemical modification of epoxidized natural rubber

Vermeulen, Johannes Petrus (1999-12)

Thesis (M.Sc) -- University of Stelllenbosch,1999.

Thesis

ENGLISH ABSTRACT: This study concerns the grafting and chemical modification of a commercially available epoxidized natural rubber (ENR50) by means of the emulsion polymerization technique. The following were investigated experimentally: three different techniques used for the emulsion polymerization process (batch, delayed addition of monomer and the pre-emulsion polymerization method), the influence of surfactant on the emulsion polymerization reaction, the compatibility of polymethyl methacrylate (PMMA) and polystyrene (PS) with the ENR50, the effect of acrylic and methacrylic acid on the compatibility of ENR50 and PMMA. A Dynamic Mechanical Analyzer (DMA) and Dielectric Analyzer (DEA) were used, simultaneously, for the analysis of the grafted ENR50 and the DMA was also used separately to evaluate the impact strength of the grafted material. Using the results of the investigations a series of grafted materials was synthesized in which different surfactant and ENR50 : MMA ratios were used. This study shows, conclusively, that the best grafting takes place in the reaction using the pre-emulsion polymerization method of MMA with ENR50 and that the simultaneous use of the DMA and DEA can be used as an analytical tool to fine-tune reaction conditions.

AFRIKAANSE OPSOMMING: Die studie het betrekking op die enting en die chemiese modifikasie van 'n kommersieel beskikbare geepoksideerde natuurlike rubber (ENR50) deur middel van die emulsie polimerisasie tegniek. Die volgende is eksperimenteel ondersoek: drie verskillende tegnieke vir die emulsie polimerisasie proses (produksie, stelselmatige byvoeging van monomeer en die preemulsie polimerisasie metode), die invloed van seep op die emulsie polimerisasie reaksie, die verenigbaarheid van polimetiel-metakrilaat (PMMA) en polistireen (PS) met die ENR50, die effek van akrielsuur en metakrielsuur op die verenigbaarheid van ENR50 en PMMA. 'n Dinamiese Meganiese Analiseerder (DMA) en Dielektrikum Analiseerder (DEA) is gelyktydig gebruik vir die analise van die geente ENR50 terwyl die DMA ook apart gebruik is om die impak-krag van die geente materiaal te evalueer. Die resultate van die ondersoeke is gebruik om 'n reeks geente materiaal te sintetiseer waarin verskillende seep en ENR50 : MMA verhoudings gebruik is. Die studie bewys, onweerlegbaarl dat enting verkieslik tydens die reaksie plaasvind waar die pre-emulsie polimerisasie metode van MMA met ENRSO toegepas is en dat die gelyktydige gebruik van die DMA en DEA gebruik kan word as die analitiese instrument om die reaksie kondisies fyn in te stel.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/51483
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