800778
Description
Mind Map by Nasuha Marzuki, updated more than 1 year ago
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Created by Nasuha Marzuki
over 10 years ago
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TEST RELATED TO PHYSICAL PROPERTIES
- PARTICLE SIZE DISTRIBUTION
- Not an important property
- The final properties of the latex products
not dependent on the particle size or
particle size distribution
- The final properties of the latex products
not dependent on the particle size or
particle size distribution
- Methods
- Microscope
method
- Particles of latex are made visible
- Particle size distribution : assessed by counting the number
of particles with sizes within a given range
- Microscope used : electron microscope
- Particles of latex are made visible
- Electronic counters
- Monitoring the change in the
electrical resistance as the
particles pass through a hole in
a certain tube
- The bigger the change in the resistance the bigger is
the particle size
- Monitoring the change in the
electrical resistance as the
particles pass through a hole in
a certain tube
- Scattering of
electromagnetic
radiation/photons by
latex particles
- Depends on the size of the particles, shape,
nature and the concentration of the
dispersed particles
- By analysing the nature can evaluate the size of the particles
- Depends on the size of the particles, shape,
nature and the concentration of the
dispersed particles
- Adsorption of
surface active
substances at the
interface between
particles &
dispersion medium
- Latex is titrated against an appropriate
surface-active substance of known
concentration
- Latex is titrated against an appropriate
surface-active substance of known
concentration
- Microscope
method
- Not an important property
- SURFACE TENSION
- NR latex have higher
surface free energies
than do polymer
solutions
- High surface , difficult to wet out some solid surfaces with aqueous lattices
- If the surface is greasy,
incomplete products will
be produced
- High surface , difficult to wet out some solid surfaces with aqueous lattices
- Method
- The du Nouy method
- Measured the force required to pull a
small metal-wire ring of circular
cross-section out of the surface of the
latex
- Measured the force required to pull a
small metal-wire ring of circular
cross-section out of the surface of the
latex
- The du Nouy method
- NR latex have higher
surface free energies
than do polymer
solutions
- VISCOSITY
- thickness of the latex products depends on its viscosity
- Depends on
- Shear rate : viscosity decreases with increasing shear rate (shear
thinning).
- Total solid content (TSC)
- Temperature of measurement
- Should be quoted with viscosity value
- Should be quoted with viscosity value
- Shear rate : viscosity decreases with increasing shear rate (shear
thinning).
- Method
- Brookfield Viscometer called as technical
viscometer
- Brookfield Viscometer called as technical
viscometer
- Useful for
- Latex quality-control purposes
- Compound development
- Latex quality-control purposes
- thickness of the latex products depends on its viscosity
- DENSITY
- Purpose
- As an indicator of rubber content
- For converting volume to mass
- As an indicator of rubber content
- Measurement
- Any chosen temperature
- Should be quoted with the result
- Any chosen temperature
- Formula
- mL - mass of latex in the density bottle
- mw - mass water in the density bottle
- ρw - the density the distilled water at the bath temperature
- mL - mass of latex in the density bottle
- Purpose
Media attachments
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