logging in or signing up plastics aSGuest3382 Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 445 Category: Entertainment License: All Rights Reserved Like it (0) Dislike it (0) Added: November 18, 2008 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript Plastics : Plastics Question: : Question: Which is more effective at cleaning your hair: a thick, viscous shampoo or a thin, freely flowing shampoo, or are they probably about equal? Observations About Plastics : Observations About Plastics Some plastics are clear, others translucent Some plastics are stiff, others are flexible Some plastics stretch, others don’t Some plastics melt, others don’t Some plastics smell, particularly when hot Some glues dry, others harden without drying Plastic : Plastic Polymers: enormous chain or tree like molecules Chemical bonds : Chemical bonds Metallic bond electrons shared between many atoms Ionic bond atoms become oppositely charged ions Covalent bond atoms share a pair of electrons Polymerization : Polymerization Plastics employ covalent bonds Individual monomer molecules are joined This polymerization forms giant molecules Some molecules are linear chains Some are branched tree-like structures Some are networked together completely Plastic structure : Plastic structure Amorphous random mess of polymers Crystalline neatly oriented polymers Regimes : Regimes Glassy: hard, brittle solid Glass-rubber transition: leathery Rubbery plateau: flexible and elastic Rubbery flow: viscous flow but elastic Reptation: chains slide along their length Liquid flow: viscous liquid Changing regimes : Changing regimes Temperature Plasticizers Chemical dissolved in a polymer to soften it Shift a polymer’s behavior to a different regime Question: : Question: Which is more effective at cleaning your hair: a thick, viscous shampoo or a thin, freely flowing shampoo, or are they probably about equal? Thermoplastics : Thermoplastics Individual strands Change behavioral regimes when heated Thermosets : Thermosets Polymers are cross-linked Can’t melt Vulcanization: cross-linking of a thermoplastic Glues are Plastics : Glues are Plastics White Glue (Water-Soluble Plastic) Model Cement (Solvent-Soluble Plastic) Heat Melting Glue (Glue Gun Glue) UV-Hardening Acrylic Glues (Acrylates) Superglues (Cyanoacrylates) Mix-Hardening Glues (Epoxies) Oriented Plastics : Oriented Plastics Kevlar (Liquid Crystal Plastics) Spectra (Draw-Ordered Plastics) You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
plastics aSGuest3382 Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 445 Category: Entertainment License: All Rights Reserved Like it (0) Dislike it (0) Added: November 18, 2008 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript Plastics : Plastics Question: : Question: Which is more effective at cleaning your hair: a thick, viscous shampoo or a thin, freely flowing shampoo, or are they probably about equal? Observations About Plastics : Observations About Plastics Some plastics are clear, others translucent Some plastics are stiff, others are flexible Some plastics stretch, others don’t Some plastics melt, others don’t Some plastics smell, particularly when hot Some glues dry, others harden without drying Plastic : Plastic Polymers: enormous chain or tree like molecules Chemical bonds : Chemical bonds Metallic bond electrons shared between many atoms Ionic bond atoms become oppositely charged ions Covalent bond atoms share a pair of electrons Polymerization : Polymerization Plastics employ covalent bonds Individual monomer molecules are joined This polymerization forms giant molecules Some molecules are linear chains Some are branched tree-like structures Some are networked together completely Plastic structure : Plastic structure Amorphous random mess of polymers Crystalline neatly oriented polymers Regimes : Regimes Glassy: hard, brittle solid Glass-rubber transition: leathery Rubbery plateau: flexible and elastic Rubbery flow: viscous flow but elastic Reptation: chains slide along their length Liquid flow: viscous liquid Changing regimes : Changing regimes Temperature Plasticizers Chemical dissolved in a polymer to soften it Shift a polymer’s behavior to a different regime Question: : Question: Which is more effective at cleaning your hair: a thick, viscous shampoo or a thin, freely flowing shampoo, or are they probably about equal? Thermoplastics : Thermoplastics Individual strands Change behavioral regimes when heated Thermosets : Thermosets Polymers are cross-linked Can’t melt Vulcanization: cross-linking of a thermoplastic Glues are Plastics : Glues are Plastics White Glue (Water-Soluble Plastic) Model Cement (Solvent-Soluble Plastic) Heat Melting Glue (Glue Gun Glue) UV-Hardening Acrylic Glues (Acrylates) Superglues (Cyanoacrylates) Mix-Hardening Glues (Epoxies) Oriented Plastics : Oriented Plastics Kevlar (Liquid Crystal Plastics) Spectra (Draw-Ordered Plastics)