- Title
- Evaluation of p-menthane-3, 8-diol citronellal acetal as a suitable bio-plasticizer for polyvinyl chloride
- Creator
- Ncanywa, Luphumlo
- Subject
- Polyvinyl chloride Chlorine compounds
- Date Issued
- 2016
- Date
- 2016
- Type
- Thesis
- Type
- Masters
- Type
- MSc
- Identifier
- http://hdl.handle.net/10948/45898
- Identifier
- vital:39317
- Description
- The main aim of this project is to test novel naturally-derived plasticizers (bio-plasticizers) synthesized at Innoventon and to determine if they are a suitable replacement for conventional plasticizers used to plasticize polyvinyl chloride. Polyvinyl chloride (PVC) is one of the most common plastics used in the world because of its durability and low cost. PVC when blended with plasticizers is a versatile thermoplastic and is used in many applications. A plasticizer is a substance that is added to a material, usually a polymer, to increase flexibility, softness and workability. Many elastomers and polymers are tough and dry; therefore they need plasticizers to make them useful. A plasticizer must be thoroughly incorporated in the elastomer or polymer in order for it to be effective. There are many types of plasticizers used in the world. Phthalate plasticizers are the most commonly used plasticizers of the past century. They comprise 92% of the global production of plasticizers. DEHP (di-ethyl hexyl phthalate) is the most widely used phthalate plasticizer. Phthalate plasticizers have been proved to be harmful to the environment and human beings. They can cause many harmful diseases to humans e.g. kidney failure, heart disease, liver failure, fertility and growth disorders. They lower testosterone in baby boys that are exposed through breast milk. In light of the above, the use of certain phthalates has been banned in cosmetics and consumer products. Since there is sufficient evidence to raise fears over the use of phthalate plasticizers, there is a great opportunity to find a way to replace phthalate plasticizers in PVC with bio-plasticizers. The current study represents the first step in developing alternative plasticizers for PVC and other polymers. These alternative plasticizers are characterized by low toxicity, low migration and are less harmful to the environment and human beings. p-menthane-3, 8-diol citronellal acetal is one such proposed bio-plasticizer which has a similar structure to the phthalates and has been previously reported by Innoventon to have potential plasticizing characteristics. During this study PVC was plasticized with PMD-citronellal acetal and tested for plasticizing properties. The plasticizing effect of PMD-citronellal acetal in PVC films was compared to that of conventional plasticizer dibutyl phthalate (DBP). The two plasticizers‟ performance was evaluated by preparing PVC films with varying amounts of each plasticizer and PMD-citronellal acetal subjecting the films to a series of tests. Tensile strength and elongation tests were performed on the plasticized and unplasticized films but these tests did not produce consistent results due to premature failures on the films. However, tensile strength was reduced in some films for both plasticizers compared to unplasticized film. Elongation and flexibility were increased in some samples as the percentage of plasticizer in each film was increased. Glass transition temperatures were determined for the plasticized and unplasticized PVC films. Glass transition temperature of both plasticizers was reduced as the percentage of plasticizer in each film was increased. Multiple regression analysis was done on the data to compare the similarity of the two plasticizers. The statistical tests showed that DBP and PMD-citronellal acetal have the same plasticization property with regard to glass transition temperature of PVC. The thermal stability of the PVC films with the two plasticizers was evaluated. Similar thermal stability was observed on the PVC, PVC with DBP and PVC with PMD-citronellal acetal. The leaching of the PMD-citronellal acetal and DBP were compared. The plasticizer loss increased as the percentage of each plasticizer in the PVC increased. The relationship between the percentage of the plasticizers and leaching rate was further analysed using multiple linear regressions. The two plasticizers were found to have the same leaching rate. FTIR analysis was performed on the plasticized and unplasticized PVC films to identify functional groups present and to determine whether the plasticizers formed any bonds with PVC functional groups. The characteristics bands of PVC were observed in FTIR. The FTIR spectra indicated that the plasticizers were incorporated into the PVC matrix without bonding. The results of the tests showed that PMD-citronellal acetal can be a suitable bio-plasticizer for PVC since it exhibited similar plasticization properties to DBP with regard to glass transition temperatures, leaching rates and thermal stability. Regarding tensile strength and elongation, further testing has to be done as the preliminary results were inconclusive. PMDcitronellal acetal was shown to be a possible alternative for DBP.
- Format
- 101 leaves
- Format
- Publisher
- Nelson Mandela Metropolitan University
- Publisher
- Faculty of Science
- Language
- English
- Rights
- Nelson Mandela Metropolitan University
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NMMU School of BioMolecular and Chemical Sciences
| Thumbnail | File | Description | Size | Format | |||
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| View Details Download | SOURCE1 | Luphumlo Ncanywa.pdf | 2 MB | Adobe Acrobat PDF | View Details Download |