Transcript No Slide Title

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
D1
D2
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
CN
CH2=C-COOCH3
The polymerisation reaction is triggered by traces
of water, generally present on the surface to be
bonded
Melting temperatures of common polymers
•Polyethylene PE 100 °C
•Polypropylene PP 130 °C
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
Extruded product
OUT
Increasing temperature along the extruder barrel
Hall: Polymer Materials, 2nd edn
Polymer forming: simple extrusion
Granules of raw
thermoplastic
IN
Extruded product
OUT
Increasing temperature along the extruder
Hall: Polymer Materials, 2nd edn
Die
swell
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