370
Answers to the Quickies
4. The term “nature-identical” in the context
of vanillin means that vanillin is a naturally
occurring aroma which, in the case of a
nature-identical substance, has not been
synthetically produced from natural sources
but, for example, from petrochemical raw
materials.
5. The percentage of synthetic fragrances and
aromas is about 75%.
6. The essential oil from the skin of lime is
obtained both by pressing and by steam
distillation. Due to the influence of temperature during distillation, the aroma of lime oil
changes, which is desirable for some
applications.
7. Typical solvents for the extraction of essential oils from plant components are alcohols
such as ethanol or methanol. Toluene, hexane or petroleum ether are also commonly
used. Supercritical CO 2 can also be used.
This can be easily removed after extraction
and its properties, e.g. viscosity or density,
can be adjusted by temperature and pressure.
8. Enfleurage is a special and long-established
method of extracting petals with low-odor
animal fats. In the enfleurage à chaud process, the fat and the flowers to be extracted
are heated together to approx. 60 °C, which
allows a faster but less gentle extraction
than compared to enfleurage at ambient
temperature. The obtained fats are called
pomade, from which the essential oils can
be extracted with ethanol.
9. The Florentine bottle is the receiver into
which the condensed mixture of essential
oils and water enters after steam distillation. It allows the continuous separation
of the relatively large water phase from the
rather small oil phase. The oil phase can be
removed at the top of the bottle, while the
water is returned to distillation via a siphon.
10. The most gentle method to obtain essential
oils from precious flowers is enfleurage à
froid. Here, the fragrances from the flowers
are released into odorless fat at ambient
temperature over a long period of time. This
means that the fragrances are not subject
to any thermal or solvent-based stress, and
their character is completely retained.
Answers to 7 Chap. 19
1. The term “bioplastics” may in principle be
used for biogenic plastics, biodegradable
plastics and biocompatible plastics.
2. Advantages of biogenic plastics can be, for
example, their CO 2 neutrality, the conservation of limited fossil raw materials, biocompatibility and biodegradability.
3. The term biodegradability is often limited to
composting in large-scale (e.g. municipal)
composting plants. The relevant seals are
awarded under standardised conditions,
taking into account various criteria which
often cannot be fulfilled with domestic compost. Most biopolymers can therefore not be
composted in the garden.
4. Celluloid is the oldest thermoplastic.
Celluloid is an ester of cellulose with nitric
acid, the so-called nitrocellulose. Mixed
with camphor, a natural terpene, a plastic is
obtained that was initially used as a substitute for billiard balls otherwise made of
ivory. Another important historical application was the production of film carriers.
Today, "nitrocellulose" is still used for the
production of table tennis balls.
5. The production of clothes has been based
on wool from sheep, leather from animal
skins and silk from silkworms since ancient
times.
6. The abbreviation PHA stands for polyhydroxyalkanoates. These polymers are
biogenic polyesters formed by certain
bacteria under anaerobic conditions to store
carbon. Typical monomers of PHA are the
hydroxycarboxylic acids 3-hydroxybutyric
acid and 3-hydroxyvaleric acid. The technical production is initially carried out in a
growth fermenter to multiply the bacteria;
in a second step, the formation of PHA
is initiated under anaerobic conditions.
Finally, the fermentation broth is extracted
with solvents and the PHA is obtained after
removal of the solvent.
7. Lactic acid is formed by microorganisms in
a fermenter and then precipitated as lactate,
e.g. by adding calcium hydroxide. The lactic
acid is released again by the addition of
sulfuric acid and then prepolymerized. The
Answers to the Quickies
4. The term “nature-identical” in the context
of vanillin means that vanillin is a naturally
occurring aroma which, in the case of a
nature-identical substance, has not been
synthetically produced from natural sources
but, for example, from petrochemical raw
materials.
5. The percentage of synthetic fragrances and
aromas is about 75%.
6. The essential oil from the skin of lime is
obtained both by pressing and by steam
distillation. Due to the influence of temperature during distillation, the aroma of lime oil
changes, which is desirable for some
applications.
7. Typical solvents for the extraction of essential oils from plant components are alcohols
such as ethanol or methanol. Toluene, hexane or petroleum ether are also commonly
used. Supercritical CO 2 can also be used.
This can be easily removed after extraction
and its properties, e.g. viscosity or density,
can be adjusted by temperature and pressure.
8. Enfleurage is a special and long-established
method of extracting petals with low-odor
animal fats. In the enfleurage à chaud process, the fat and the flowers to be extracted
are heated together to approx. 60 °C, which
allows a faster but less gentle extraction
than compared to enfleurage at ambient
temperature. The obtained fats are called
pomade, from which the essential oils can
be extracted with ethanol.
9. The Florentine bottle is the receiver into
which the condensed mixture of essential
oils and water enters after steam distillation. It allows the continuous separation
of the relatively large water phase from the
rather small oil phase. The oil phase can be
removed at the top of the bottle, while the
water is returned to distillation via a siphon.
10. The most gentle method to obtain essential
oils from precious flowers is enfleurage à
froid. Here, the fragrances from the flowers
are released into odorless fat at ambient
temperature over a long period of time. This
means that the fragrances are not subject
to any thermal or solvent-based stress, and
their character is completely retained.
Answers to 7 Chap. 19
1. The term “bioplastics” may in principle be
used for biogenic plastics, biodegradable
plastics and biocompatible plastics.
2. Advantages of biogenic plastics can be, for
example, their CO 2 neutrality, the conservation of limited fossil raw materials, biocompatibility and biodegradability.
3. The term biodegradability is often limited to
composting in large-scale (e.g. municipal)
composting plants. The relevant seals are
awarded under standardised conditions,
taking into account various criteria which
often cannot be fulfilled with domestic compost. Most biopolymers can therefore not be
composted in the garden.
4. Celluloid is the oldest thermoplastic.
Celluloid is an ester of cellulose with nitric
acid, the so-called nitrocellulose. Mixed
with camphor, a natural terpene, a plastic is
obtained that was initially used as a substitute for billiard balls otherwise made of
ivory. Another important historical application was the production of film carriers.
Today, "nitrocellulose" is still used for the
production of table tennis balls.
5. The production of clothes has been based
on wool from sheep, leather from animal
skins and silk from silkworms since ancient
times.
6. The abbreviation PHA stands for polyhydroxyalkanoates. These polymers are
biogenic polyesters formed by certain
bacteria under anaerobic conditions to store
carbon. Typical monomers of PHA are the
hydroxycarboxylic acids 3-hydroxybutyric
acid and 3-hydroxyvaleric acid. The technical production is initially carried out in a
growth fermenter to multiply the bacteria;
in a second step, the formation of PHA
is initiated under anaerobic conditions.
Finally, the fermentation broth is extracted
with solvents and the PHA is obtained after
removal of the solvent.
7. Lactic acid is formed by microorganisms in
a fermenter and then precipitated as lactate,
e.g. by adding calcium hydroxide. The lactic
acid is released again by the addition of
sulfuric acid and then prepolymerized. The