Polypropylene Crystallization
Contents
1. Introduction and literature review
1.1 Polypropylene
1.1.1 Polypropylene crystallization
1.2 Polymer degradation
1.3 Broadband dielectric
1.4 Solubility and the cohesive energy density
1.5 Literature review
2. Experimental method
2.1 Solubility of SN 1010 in various solvents
2.2 Calibration curve
2.3 Preparation of polymer/antioxidant mix for films
2.4 Soxhlet extraction
2.5 Broadband dielectric analysis of films
2.6 Broadband dielectric analysis of molten samples
3. Results and discussion
3.1 Solubility of SN 1010 in various solvents
3.2 Calibration curve
3.3 Soxhlet extraction
3.4 Broadband dielectric analysis of films
3.5 Broadband dielectric analysis of molten samples
3.5.1 Discussion of method
4. Conclusion
1. Introduction and literature review
1.1 Polypropylene
Packaging for the protection and storage of food products is commonly made from plasticsA. Polypropylene, fig 1, is a common polymer for this type of use.
Figure 1. The repeating unit of Polypropylene.
Polypropylene can be either isotactic or syndiotactic. Isotactic polypropylene has a more crystalline structure and the more crystalline the structure the higher the melting point will be. In isotactic polypropylene the methyl groups are all on the same side of the long chain. In syndiotactic polypropylene the methyl group alternates between both sides of the chain.
1.1.1 polypropylene crystallization
There are two main processes during the crystallization of polypropyleneG. Primary crystallization and secondary crystallization. Primary crystallization comprises of the growth of spherulites. It is thought that this primary phase is heterogeneous and relies on impurities for the formulation of nuclei. From here the nuclei grow outwards forming crystalline fibrils. Each fibrils are made up of lamellae. Secondary crystallization is the thickening of lamellae or the growth of new lamellae in-between existing lamellae. The
1. Introduction and literature review
1.1 Polypropylene
1.1.1 Polypropylene crystallization
1.2 Polymer degradation
1.3 Broadband dielectric
1.4 Solubility and the cohesive energy density
1.5 Literature review
2. Experimental method
2.1 Solubility of SN 1010 in various solvents
2.2 Calibration curve
2.3 Preparation of polymer/antioxidant mix for films
2.4 Soxhlet extraction
2.5 Broadband dielectric analysis of films
2.6 Broadband dielectric analysis of molten samples
3. Results and discussion
3.1 Solubility of SN 1010 in various solvents
3.2 Calibration curve
3.3 Soxhlet extraction
3.4 Broadband dielectric analysis of films
3.5 Broadband dielectric analysis of molten samples
3.5.1 Discussion of method
4. Conclusion
1. Introduction and literature review
1.1 Polypropylene
Packaging for the protection and storage of food products is commonly made from plasticsA. Polypropylene, fig 1, is a common polymer for this type of use.
Figure 1. The repeating unit of Polypropylene.
Polypropylene can be either isotactic or syndiotactic. Isotactic polypropylene has a more crystalline structure and the more crystalline the structure the higher the melting point will be. In isotactic polypropylene the methyl groups are all on the same side of the long chain. In syndiotactic polypropylene the methyl group alternates between both sides of the chain.
1.1.1 polypropylene crystallization
There are two main processes during the crystallization of polypropyleneG. Primary crystallization and secondary crystallization. Primary crystallization comprises of the growth of spherulites. It is thought that this primary phase is heterogeneous and relies on impurities for the formulation of nuclei. From here the nuclei grow outwards forming crystalline fibrils. Each fibrils are made up of lamellae. Secondary crystallization is the thickening of lamellae or the growth of new lamellae in-between existing lamellae. The
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