362
Answers to the Quickies
are biodegradable, skin-friendly non-ionic
surfactants consisting exclusively of renewable raw materials.
7. Glucose is converted with methylamine
under water elimination in the presence of
hydrogen to N-methylglucamine, which
then reacts with a fatty acid methyl ester
to form N-methylglucamide. The fatty
acid glucamides are also well degradable,
skin-compatible surfactants.
8. About 5% of lactose is contained in cow’s
milk. After separation of the fat and the
casein from the milk, the whey remains,
from which lactose crystallises during
evaporation.
9. Preparation of the sugar juice (washing
and crushing of the beets, extraction of the
sucrose with 70 °C hot water), purification
of the sugar juice (by liming, carbonation
and filtration), thickening of the thin juice
in a multistage evaporator station to the
thick juice and multistage crystallization
in the cooking station. The by-products are
pellets and molasses, which are partly used
as animal feed, and carbokalk, which can be
used as fertilizer.
10. Hydrolysis leads to invert sugar, conversion
with carboxylic acids to esters, telomerization with butadiene to ethers with octadienyl chains, chlorination to sucralose,
oxidation to polyhydroxypolycarboxylic
acids and isomerization to isomaltulose.
Answers to 7 Chap. 7
1. 40–50% cellulose; 10–20% hemicelluloses;
20–30% lignin; 5–10% secondary components such as resins, waxes and turpentine
oils.
2. Cellulose consists of glucose monomers
linked together in a β-1,4-glycosidic
manner. Long linear chains with molecular masses of up to one million Dalton are
formed. The molecular chains are partially
connected to each other via hydrogen bonds
and form crystalline regions.
3. The wood chips are pretreated with
low-pressure steam in a presteamer and
then transported to the cooker via a pressure lock. At temperatures around 180 °C, a
pressure of approx. 10 bar is reached in the
cooker. The decomposition takes place with
a caustic solution of NaOH, sodium sulfide
and sodium carbonate. After decomposition,
the pulp is washed and the lye reprocessed.
Sodium sulfate is added to the lye to compensate for the sulfur losses.
4. In the sulfate process, the ether bonds in the
lignin are cleaved by the influence of the hot
caustic soda lye and phenolic compounds
are released, which accumulate in the black
liqour. In the sulfite process, water-soluble
lignosulfonic acids are formed, which are
present in the sulfite liquor.
5. Fillers, pigments and binding agents are
added to the paper.
6. Cellulose is swollen in 20% caustic soda
solution to alkali cellulose, then converted
with carbon disulfide to xanthate and the
aqueous solution of the cellulose xanthate is
injected into a precipitation bath consisting
of sulfuric acid and sulfates. The spinnable
filament of the viscose silk is formed.
7. An alternative is the Lyocell process, in
which cellulose is dissolved in NMMO.
From the homogeneous solution, a thread
can be spun again.
8. Cellulose triacetate forms when cellulose
is converted with a significant excess of
acetic acid. Cellulose diacetate cannot be
formed by using a smaller amount of acetic
acid: Mixtures of mono-, di- and triacetates
are then always formed. Targeted partial
hydroly sis of the triacetate to the diacetate is
more effective.
9. If the hydroxyl groups are substituted by
nitrate groups, the lacquer wool forms at a
DS up to 70%, the collodion wool at a DS
up to 85% and the gun cotton at a DS up to
90%.
10. Important cellulose ethers are carboxymethylcellulose CMC (graying inhibitor in
detergents), methylcellulose MC (wallpaper
glue, thickener), hydroxyethylcellulose HEC
(viscosity improver, protective colloid),
ethylcellulose EC and hydroxypropylcellulose HPC (both used in adhesives, in
construction chemicals and in pharmaceuticals).
Answers to the Quickies
are biodegradable, skin-friendly non-ionic
surfactants consisting exclusively of renewable raw materials.
7. Glucose is converted with methylamine
under water elimination in the presence of
hydrogen to N-methylglucamine, which
then reacts with a fatty acid methyl ester
to form N-methylglucamide. The fatty
acid glucamides are also well degradable,
skin-compatible surfactants.
8. About 5% of lactose is contained in cow’s
milk. After separation of the fat and the
casein from the milk, the whey remains,
from which lactose crystallises during
evaporation.
9. Preparation of the sugar juice (washing
and crushing of the beets, extraction of the
sucrose with 70 °C hot water), purification
of the sugar juice (by liming, carbonation
and filtration), thickening of the thin juice
in a multistage evaporator station to the
thick juice and multistage crystallization
in the cooking station. The by-products are
pellets and molasses, which are partly used
as animal feed, and carbokalk, which can be
used as fertilizer.
10. Hydrolysis leads to invert sugar, conversion
with carboxylic acids to esters, telomerization with butadiene to ethers with octadienyl chains, chlorination to sucralose,
oxidation to polyhydroxypolycarboxylic
acids and isomerization to isomaltulose.
Answers to 7 Chap. 7
1. 40–50% cellulose; 10–20% hemicelluloses;
20–30% lignin; 5–10% secondary components such as resins, waxes and turpentine
oils.
2. Cellulose consists of glucose monomers
linked together in a β-1,4-glycosidic
manner. Long linear chains with molecular masses of up to one million Dalton are
formed. The molecular chains are partially
connected to each other via hydrogen bonds
and form crystalline regions.
3. The wood chips are pretreated with
low-pressure steam in a presteamer and
then transported to the cooker via a pressure lock. At temperatures around 180 °C, a
pressure of approx. 10 bar is reached in the
cooker. The decomposition takes place with
a caustic solution of NaOH, sodium sulfide
and sodium carbonate. After decomposition,
the pulp is washed and the lye reprocessed.
Sodium sulfate is added to the lye to compensate for the sulfur losses.
4. In the sulfate process, the ether bonds in the
lignin are cleaved by the influence of the hot
caustic soda lye and phenolic compounds
are released, which accumulate in the black
liqour. In the sulfite process, water-soluble
lignosulfonic acids are formed, which are
present in the sulfite liquor.
5. Fillers, pigments and binding agents are
added to the paper.
6. Cellulose is swollen in 20% caustic soda
solution to alkali cellulose, then converted
with carbon disulfide to xanthate and the
aqueous solution of the cellulose xanthate is
injected into a precipitation bath consisting
of sulfuric acid and sulfates. The spinnable
filament of the viscose silk is formed.
7. An alternative is the Lyocell process, in
which cellulose is dissolved in NMMO.
From the homogeneous solution, a thread
can be spun again.
8. Cellulose triacetate forms when cellulose
is converted with a significant excess of
acetic acid. Cellulose diacetate cannot be
formed by using a smaller amount of acetic
acid: Mixtures of mono-, di- and triacetates
are then always formed. Targeted partial
hydroly sis of the triacetate to the diacetate is
more effective.
9. If the hydroxyl groups are substituted by
nitrate groups, the lacquer wool forms at a
DS up to 70%, the collodion wool at a DS
up to 85% and the gun cotton at a DS up to
90%.
10. Important cellulose ethers are carboxymethylcellulose CMC (graying inhibitor in
detergents), methylcellulose MC (wallpaper
glue, thickener), hydroxyethylcellulose HEC
(viscosity improver, protective colloid),
ethylcellulose EC and hydroxypropylcellulose HPC (both used in adhesives, in
construction chemicals and in pharmaceuticals).