#6 Research Initiatives-Susie Kirsh
Blog #6 – Research Initiatives
Cotton Testing
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Bags of cottons brought in for
conditioning
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Samples are individually taken out and
placed in trays
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Air is conditioned so that the heat
and humidity are similar to the air during testing
o
Done to create consistency among
sample
-
Samples are then tested when they
reach the right level (temperature)
-
Technician tests and pulls them into
lab
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Samples are tested in both small
amounts and large amounts
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Machine pulls out and combs the cotton
and then is cut straight across, evenly
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Then samples are checked again
Technical Polyester
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Polyester
o
Produced from polyethylene
terephthalate (PET polymer)
o
Molecular weight of PET polymer –
20,000-40,000
o
Raw materials for preparation:
§ Dimethyl
terephthalate (DMT) or Terephthalic Acid (TPA)
§ Monoethylene
Glycol (MEG)
-
Production
o
Two routes, each route consists of two
step esterification process
§ Route
1: from Purified Terephthalic Acid (TPA)
§ Route
2: from Dimethyl terephthalate (DMT)
o
Two Steps:
§ Step
1: Transesterification or Direct esterification resulting in Prepolymer
de-glycol terephthalate (DGT)
§ Step
2: DGT polymerized by polycondensation
o
Two Methods:
§ Bath
Process – two separate autoclaves used: one for transesterification or
esterification reaction and second for polycondensation process; production
limited; cost of production is high
§ Continuous
Process

o
Two Step Process
§ Advantageous
·
To keep the raw materials during polymerization
in equimolar (1:1) proportion
·
Higher speed of reaction
·
Less side reactions
·
Better thermal stability of melt
·
Good color of polymer
·
Better drawability
-
Properties
o
Density (gm/cc) – 1.38
o
Moisture regain (%) – 0.4 at 65%rh
o
Breaking tenacity (gpd) – 3-10
o
Softening temperature (Celsius) –
225-230 degrees
o
Melting temperature (Celsius) –
255-265 degrees
o
Effect on Acids – good resistance to
organic acids and inorganic acids at room temperature but degrades and
dissolves in concentrated Sulfuric acid
I appreciate how well organized your thoughts are on these topics and how easy to understand your notes are.
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