Experiment 25: ORGANIC POLYMERS: THE SYNTHESIS OF NYLON.
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Transcript of Experiment 25: ORGANIC POLYMERS: THE SYNTHESIS OF NYLON.
Experiment 25:
ORGANIC POLYMERS: THE SYNTHESIS OF NYLON
Objectives:
To synthesize Nylon 6,10 from hexamethylene diamine and sebacoyl chloride.
To determine the length of the Nylon formed using a simple mathematical calculation.
SYNTHESIS OF AN AMIDE
Carboxylic Acid
Reacting a carboxylic acid with an amine yields an amide. Water is a by-product, and this reaction is slow without a catalyst.
R N
H
H
+ C
O
HO
R catalystR N
H
C
O
R + H2O
amine amide
SYNTHESIS OF AN AMIDE
amine Acid chloride
amide
R N
H
H
+ C
O
Cl
R R N
H
C
O
R + HCl
By using a carboxylic acid chloride, a more reactive carboxylic acid derivative, the rate of reaction can be increased. In this reaction, HCl is the by-product.
MECHANISM
RC
Cl
O
+
R'N
H
H
RC
Cl
O
NR' H
H
+ OHR
CCl
O
NR' H
RC
N
O
H
R'
SYNTHESIS OF NYLON 6,10
In order to make a polyamide, such as Nylon 6,10, the amine molecule must have a –NH2 group at each end, and the acid chloride must have a –COCl group at each end.
The diamine and the diacid chloride bond together, end-on-end, to form very long chains.
Nylon 6,10 is made from hexamethylene diamine (the diamine) and sebacoyl chloride (the diacid chloride).
Hexamethylene diamine
Sebacoyl
chloride
N
H
H
CH2CH2CH2CH2CH2CH2 N
H
H
C
O
Cl
CH2CH2CH2CH2CH2CH2CH2CH2 C
O
Cl
SYNTHESIS OF NYLON 6,10
N
H
H
CH2CH2CH2CH2CH2CH2 N
H
H
C
O
Cl
CH2CH2CH2CH2CH2CH2CH2CH2 C
O
Cl
HN CH2CH2CH2CH2CH2CH2
HN C
O
CH2CH2CH2CH2CH2CH2CH2CH2 C
O
HN CH2CH2CH2CH2CH2CH2
HN HCl
HN (CH2)6
HN C
O
(CH2)8 C
O
+
+
Nylon 6,10 =n n
Hexamethylene diamine
Sebacoyl
chloride
CLASSIFICATIONS OF SYNTHETIC POLYMERS
Synthetic polymers are classified by their method of synthesis.
Chain-growth Step-growth
polystyrene Polyamides (nylon)
Synthetic Method
NATURAL ORGANIC POLYMERS
Proteins
hair, skin, tissue
Polysaccharides
cellulose, starch
Polynucleotides
DNA, RNA
SYNTHETIC ORGANIC POLYMERS
Nylons Polyesters Acrylics Polyvinyls
Plastic sheeting and plumbing materials
Polystyrenes Insulating materials
EXPERIMENTAL PROCEDURE
(Synthesis)
Pour diamine solution and diacid chloride in separate beakers.
Using forceps, grasp the film that forms at the interface of the two liquids.
Pull up slowly and wrap end of nylon string around a test tube.
Rotate the tube and count the number of revolutions made before no more nylon can be produced.
EXPERIMENTAL PROCEDURE
(Analysis)
Calculate the length of the nylon string produced (in meters) using the following equation:
Nylon produced (m) = (test tube diameter (m)) X () X (# test tube revolutions )
Table 25.1
Test tube diameter (mm)
# of test tube revolutions
Length of nylon (m)
SAFETY CONCERNS
CAUTION:All chemicals are hazardous to the skin and eyes. Safety goggles and gloves are required during the experiment!!!
WASTE MANAGEMENT
Pour all waste from synthesis and solubility tests into container labeled “ORGANIC WASTE (Polymers)”
CLEANING
Clean all glassware with soap, water, brush, and rinse with wash acetone before returning to lab drawer!
DO NOT return any glassware to lab drawer dirty or wet!