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Solid Materials. Plastics. Ceramics. Metals. Thermo -settings. Thermoplastics. Commodity. Engineering. Specialty. PLASTICS. THERMOPLASTICS Linear or slightly branched polymer – addition/condensation Repeated softened at elevated temperature and solidified on cooling
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Solid Materials Plastics Ceramics Metals Thermo -settings Thermoplastics Commodity Engineering Specialty www.cse-annauniv.weebly.com
PLASTICS THERMOPLASTICS • Linear or slightly branched polymer – addition/condensation • Repeated softened at elevated temperature and solidified on cooling • No chemical changes occur • Molecules are held by secondary forces THERMOSETTING PLASTICS • Do not form linear chain – forms 3 –dimensional structure • Hard and infusible and cannot be softened without decomposition • Molecules are held by primary forces. www.cse-annauniv.weebly.com
FAMILIES OF POLYMER MATERIALS www.cse-annauniv.weebly.com
Polymers are a large class of materials consisting of many small molecules (called monomers) that can be linked together to form long chains, thus they are known as macromolecules www.cse-annauniv.weebly.com
Amorphous Vs Crystalline An amorphous solid is formed when the chains have little orientation throughout the bulk polymer. The glass transition temperature is the point at which the polymer hardens into an amorphous solid. This term is used because the amorphous solid has properties similar to glass. In the crystallization process, it has been observed that relatively short chains organize themselves into crystalline structures more readily than longer molecules. Therefore, the degree of polymerization (DP) is an important factor in determining the crystallinity of a polymer. Polymers with a high DP have difficulty organizing into layers because they tend to become tangled www.cse-annauniv.weebly.com
Thermoplastics From melt to solid www.cse-annauniv.weebly.com
Various Thermoplastics PI Specialty Polymers PTFE PSU LCP PES HPPA PPSU PA Engineering Polymers PC POM PET PBT PPO TPE ABS PMMA Commodities PE-UHMW PP-GF PS PVC PP PE-HD SAN PE-LD AMORPHOUS CRYSTALLINE www.cse-annauniv.weebly.com
Why Use Thermoplastics? • Increased performance • Corrosion resistance • Weight reductions (specific strength & stiffness) • Cost reduction! • Parts consolidation & net shape formation • Process elimination (painting, machining, assembly) • Economics of injection molding • Properties can be altered to suit the needs • Good strength/weight ratio • Tough & durable • Non toxic • Easy processability • Chemical/Moisture Resistant • Fire retardant • Do not rust/corrode. • Resistant to microbes • Attractive colours • Good weatherability • Practically maintenance free • Reusable / Recyclable www.cse-annauniv.weebly.com
Low Density Polyethylene(LDPE) www.cse-annauniv.weebly.com
STRENGTHS LIMITATIONS Susceptible to environmental stress cracking Low strength, stiffness and maximum service temperature High gas permeability, particularly carbon dioxide Poor UV resistance Highly flammable High-frequency welding and joining impossible Poor scratch and abration resistance • Very low cost • Excellent chemical resistance • Very good process-ability • High impact strength at low temperature • Excellent electrical insulating properties • Very low water absorption • FDA compliant • Can be transparent in thin film form • Since it is non-polar, electrical properties are almost independent of temperature and frequency • Tg is well below the room temperature www.cse-annauniv.weebly.com
Processability www.cse-annauniv.weebly.com
Packaging www.cse-annauniv.weebly.com
Agriculture www.cse-annauniv.weebly.com
Linear Low Density Polyethylene (LLDPE) www.cse-annauniv.weebly.com
Packaging www.cse-annauniv.weebly.com
Applications of LDPE & LLDPE Bottle Caps Green House Cable Sheathing Pouch www.cse-annauniv.weebly.com
High Density Polyethylene (HDPE) www.cse-annauniv.weebly.com
Polypropylene (PP) www.cse-annauniv.weebly.com
Packaging www.cse-annauniv.weebly.com
Health Care www.cse-annauniv.weebly.com
Polyvinyl Chloride (PVC) www.cse-annauniv.weebly.com
Electrical www.cse-annauniv.weebly.com
Building and Construction www.cse-annauniv.weebly.com
Packaging www.cse-annauniv.weebly.com
Electrical www.cse-annauniv.weebly.com
Consumer Goods www.cse-annauniv.weebly.com
Automotive www.cse-annauniv.weebly.com
Types of Profiles : • Hollow Profiles • Foam Profiles • Doors : • Aluminium Frame + Hollow Profile • PVC Frame + Hollow Profile • PVC Frame + Foam Sheet • Door Frame • Windows • Sliding • Casement • Single Glazing • Double Glazing • Partitions • False Ceiling • Miscellaneous • (Viz... Kitchen Cabinets etc.) www.cse-annauniv.weebly.com
Versatility of PVC From Footwear….. www.cse-annauniv.weebly.com
Polystyrene (PS) www.cse-annauniv.weebly.com
Packaging www.cse-annauniv.weebly.com
