Laboratory Activity 4C (Vulcanisation of Rubber):
Aim: To produce vulcanised rubber.
Materials: Latex, ethanoic acid, CH3COOH and solution of disulphur dichloride, S2Cl2 in methylbenzene, C7H8 solution.
Apparatus: Beaker, dropper, retort stand, white tile, clip, knife and measuring cylinder.
Procedure:
1. Measure 25 cm3 of latex using a measuring cylinder and pour it into a beaker.
2. Drop 3-5 drops of ethanoic acid, CH3COOH using a dropper into the latex and stir using a glass rod.
3. Pour the latex onto the white tile and spread it over using the glass rod as shown in Figure 4.9.
4. The rubber on the white tile is left to dry for a few days.
5. Cut the dried rubber on the tile into smaller pieces using a knife.
6. Dip the rubber pieces into a disulphur dichloride, S2Cl2 solution.
7. Dry the rubber pieces by hanging them on the retort stand.
Discussion:
1. What is the function of ethanoic acid, CH3COOH?
2. Why does latex need to be spread out on the white tile?
3. How do you know vulcanised rubber is successfully produced?
Answer:
Discussion:
1. Ethanoic acid is a coagulant to coagulate the latex.
2. To obtain an even thickness.
3. Rubber strips produced are harder and can withstand high temperature.
Aim: To produce vulcanised rubber.
Materials: Latex, ethanoic acid, CH3COOH and solution of disulphur dichloride, S2Cl2 in methylbenzene, C7H8 solution.
Apparatus: Beaker, dropper, retort stand, white tile, clip, knife and measuring cylinder.
Procedure:
1. Measure 25 cm3 of latex using a measuring cylinder and pour it into a beaker.
2. Drop 3-5 drops of ethanoic acid, CH3COOH using a dropper into the latex and stir using a glass rod.
3. Pour the latex onto the white tile and spread it over using the glass rod as shown in Figure 4.9.
4. The rubber on the white tile is left to dry for a few days.
5. Cut the dried rubber on the tile into smaller pieces using a knife.
6. Dip the rubber pieces into a disulphur dichloride, S2Cl2 solution.
7. Dry the rubber pieces by hanging them on the retort stand.
Discussion:
1. What is the function of ethanoic acid, CH3COOH?
2. Why does latex need to be spread out on the white tile?
3. How do you know vulcanised rubber is successfully produced?
Answer:
Discussion:
1. Ethanoic acid is a coagulant to coagulate the latex.
2. To obtain an even thickness.
3. Rubber strips produced are harder and can withstand high temperature.