Elastic modulus of PETP: changes during fibre drawing

Hall: Polymer Materials, 2nd edn

Polymer viscoelasticity Maxwell element D Hookean elastic spring Viscous element dashpot

Polymer viscoelasticity Maxwell element D At constant applied stress

Polymer viscoelasticity Maxwell element D At constant applied strain

Polymer viscoelasticity Kelvin-Voigt element D

Polymer viscoelasticity Standard linear solid D1D1 D2D2

ADHESIVES Many commercial adhesives Four examples Polymer cement: polystyrene Latex or emulsion type: EvoStik PVA Epoxy: thermoset Araldite Cyanoacrylate: Loctite, Glasbond

ADHESIVES Polystyrene cement Solid PS polymer + solvent Liquid adhesive Bonds by solvent evaporation Yes, it’s that simple.

Latex or emulsion type adhesive EvoStik Spherical polymer particles dispersed in water Ma, Davis and Scriven Prog Org Coatings 2005, v52, 46-62

Latex coalescence Film formation As water is lost, particles come into contact and merge Ma, Davis and Scriven Prog Org Coatings 2005, v52, 46-62

Super-glue Cyanoacrylate adhesives The uncured adhesive consists of a monomer commonly CH 2 =C-COOCH 3 The polymerisation reaction is triggered by traces of water, generally present on the surface to be bonded CN

Melting temperatures of common polymers Polyethylene PE 100 °C Polypropylene PP 130 °C

Hall: Polymer Materials, 2nd edn Polymer forming: extrusion

Hall: Polymer Materials, 2nd edn Polymer forming: extrusion injection moulding

Hall: Polymer Materials, 2nd edn Polymer forming: extrusion injection moulding rotational moulding

Hall: Polymer Materials, 2nd edn Polymer forming: extrusion injection moulding rotational moulding blow moulding

Hall: Polymer Materials, 2nd edn Polymer forming: simple extrusion Granules of raw thermoplastic IN Increasing temperature along the extruder barrel Extruded product OUT

Hall: Polymer Materials, 2nd edn Polymer forming: simple extrusion Granules of raw thermoplastic IN Increasing temperature along the extruder Die swell Extruded product OUT

Polymer forming: injection moulding

Polymer forming: rotational moulding

Polymer forming: blow moulding

Netlon process for mesh Hall: Polymers, in Civil Engineering Materials, 5nd edn

Netlon process: 1992 patent (one of many)

Netlon process for mesh Hall: “Polymers”, in Civil Engineering Materials, 5nd edn, Pt VI

Netlon process for mesh Hall: “Polymers”, in Civil Engineering Materials, 5nd edn, Pt VI