Plastics

1.     Introduction. Position and development of the plastics industry, the role of plastics in the economy. Definition: macromolecule, polymer, plastic, additives, other ingredients. Types of plastics: linear and cross-linked polymers, elastomer, engineering plastics. Properties of polymers and their modification. Outline of the subject, key questions (chemistry, physics, processing, application, environmental issues).

2.   Polymerization. Radical polymerization. Basic reactions: initiation, chain propagation, chain transfer, termination. Polymerization technologies: gas phase, emulsion, suspension, bulk. Copolymerization, relative reactivity. Ionic polymerization. Stereospecific polymerization.

3. Polycondensation, cross-linked polymers. Functionality, average functionality. Molecular mass and functionality, criterion of cross-linking and the production of cross-linked polymers. Materials, short introduction to the most frequently used polymers. Thermoplastics: PE, PP, PVC, PS and its copolymers. Engineering plastics: PC, PET, PA. Thermoset resins: pheno- and aminoplasts, epoxy resins, polyesters, polyurethanes. Elastomers and rubbers.

4    Polymer physics. Conformation, the freely-jointed chain model, factors hindering conformational changes. Radius of gyration, chain-end distance, entanglements. Polymer solutions, phase diagram, solubility. Several methods to determine molecular weight. The behavior of solid polymers, rubber elasticity.

5.   Deformation and fracture. Gas, liquid and solid state. Physical states. Crystalline and amorphous materials. Themomechanical traces, transitions. Melt rheology, flow, viscosity, shear dependence. Phenomenological models, viscoelastic deformation. Unidirectional deformation, stress vs. strain traces, necking. Fracture, brittle and plastic fracture, stiffness-impact resistance correlations.

6.   Correlation of structure and properties. Relationship of the molecular and macroscopic structure of plastics, characteristic temperatures, properties. Plasticization. Semi-crystalline polymers. Crystallization, melting, polymorphism. Nucleation. Correlation between crystalline structure and properties. Structure of amorphous polymers.

7.   Modified polymers. Polymer blends, miscibility, compatibility. Particulate filled polymers, correlation between component characteristics and composite properties. Reinforcing with short and long fibers. Micromechanical deformation processes. Structure and properties. Influence of interfacial interactions.

8.   Processing of thermoplastics. Physical states and processing technologies. Melt processing, the role of viscoelasticity. Extrusion, injection molding, blow-molding, calendaring. Processing in the rubber elastic state: thermoforming. Machining.

9.   Other processing methods and products. Fiber spinning, foams, membrane technology. Reactive injection molding. Processing of cross-linkable resins. Molding epoxy resins, impregnation, polyester resins reinforced with glass fibers and mats. Phenoplast and aminoplast boards. Rubber technology, tires. Lacquers, adhesives.

10. Application of plastics. Types of plastics used as packaging materials, the corresponding processing technologies, products. The most important characteristics of plastic packaging materials (mechanical properties, aesthetics, permeability, additives, lifetime, etc.). Aspects used in the selection of plastic packaging materials (properties, economy, regulations). Packaging of food and drugs. Legal aspects of using plastic packaging materials. Automotive industry. Body and body parts, bumpers. Suspension, vibration and sound insulation. Under hood parts. Lights and other electric parts. Instrument panel, seats, floor, trunk. Electronics, informatics. Insulators and conducting plastics. Non-linear optical plastics. Light sensitive, piezoelectric and liquid crystal polymers. Household equipment, bowls, plates, utensils. Chemical industry, pipes, pumps, heat exchangers. Agriculture: green houses, irrigation systems, artificial insemination, animal identification plates. Healthcare: disposable products, catheters, etc. Building industry: pipes, wall paper, profiles, electrical parts, etc.

11. Degradation, stabilization, additives. Reasons of degradation: heat, light, oxidation, irradiation. Mechanism of degradation, chain scission, elimination, depolymerization. Type of additives: additives maintaining (stabilizers, lubricants) or modifying properties (plasticizers, fillers, colorants, blowing agents, impact modifiers, etc.). Role and mechanism of additives.

12. Plastics and the environment. Plastic waste. Life cycle analysis. Methods of waste disposal: incineration, chemical decomposition, reprocessing, dumping. Technical and financial questions of reprocessing. Natural polymers and components: starch, cellulose, wood flour. Biodegradable polymers: properties and economy. Legal issues related to the handling of plastic waste.

Laboratory practice

1.   Introduction. Presentation of the goals and method of lab practice. Instructions for the preparation of the reports and information about individual questions. Aspects of the evaluation of the work done in the lab and of the report. Information about the prevention of accidents and fire in the lab.

2.   Identification of plastics. Application of rapid methods for the identification of unknown plastics. Identification based on visual inspection and the burning test (way of burning, odor of burning material, pH, dripping). Identification of heteroatoms, solubility and density.

3.   Thermal analysis of polymers. Application of differential scanning calorimetry (DSC), polarization optical microscopy, thermo-optical methods for the study of plastic products. Differences between crystalline and amorphous polymers, analysis of correlations between structure and application properties.

4.   Mechanical properties of plastics. Tensile testing of amorphous and crystalline polymers and copolymers, evaluation and interpretation of tensile characteristics. Application of dynamic mechanical thermal analysis (DMTA) for the determination of the relaxation transition of polymers (demonstration).

5.   Extrusion of thermoplastics. Introduction to the construction and operation of the extruder. Processes taking place in the extruder and the factors determining them. Similarities and differences in industrial and laboratory extrusion. Correlations between the technological parameters of the extrusion and the properties of the product.

6.   Injection molding of thermoplastics. Parts, construction and operation of injection molding machines. Detailed presentation of processes taking place during injection molding. Structure and properties of injection molded parts. Effect of injection molding technology on the properties of injection molded parts.

7.   Plastic foams. Production of foams with physical and chemical blowing agents. Preparation of foamed polystyrene blocks. Production of soft and rigid polyurethane foams. Characterization of the structure of the foam.