Final Year Project Content

8/8/2019 Final Year Project Content

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CHAPTER 1

1.0 OVERVIEW

Natural rubber is well known to produce various types of product. One of the

platforms which latex product most frequently used is in medical site, which is called

medical examination gloves. We used latex as raw material because of its astounding

properties, which acts as a barrier of protection both for the health care worker and the

patient to guard against contact with blood, other body fluids, and microorganisms.

Despite of the protection offered by the latex gloves, there is one little thing,

which always ignored by the users. Latex product also comes with the side effect

which is famously known as Allergic Reaction which the main priority of this project.

The project is all about to identify the chemicals, which has been the cause of the

allergic reaction to occur. After that, we are going to formulate another formulation

with the chemicals which contains the cause of the allergic reaction been minimized

with the mechanical properties of the product maintained.

With the new formulation, we can reduce the amount of chemicals, which has

been the caused of such occurrences and the new formulation did not affect the

quality of our product. This project is worth doing because if we can reduced the

effect of using latex product, the quality of health can be more secured because this is

a serious matter which is still cannot be solve until now.

1.1 ALLERGIC REACTION

Over the past few years, there has been an increasing incidence of allergic

reaction among health care workers to latex medical gloves. Current estimates on theprevalence of latex allergy among health care workers range as high as 17%. This is

thought to be largely due to the institution of universal precautions in response to the

AIDS epidemic, and the resultant dramatically increases in glove usage.

In the process of producing latex gloves, there are various types of chemicals

which need to be include to produce a perfect gloves which can offers great barrier

properties in order to protect our skin from infection by blood contact which for the

safety both of the patient and also the health care worker (for medical platform).

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But despite of the awareness of the infection from outer source, most of the

users unaware of the chemicals that lies in the glove itself which also a serious threat

that can cause severe impact to the safety of the wearer.

1.2 OBJECTIVES

1) To perform a series of study about latex allergic reaction and the cause of such

reaction to occurs.

2) To perform studies on the chemicals used in latex glove production with the

guidelines from the supervisor.

3) To find a way to reduce the effect of allergic reaction which presents because

of the reaction between the accelerators resulting the production of latex

protein, which is the main focus in this project.

4) To reduce the allergic reaction by minimizing the amount of accelerators

usage.

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CHAPTER 2

LITERATURE REVIEW

2.0 LATEX

Latex is the common name for the fluid produced by many plants but it is the

latex that comes from the rubber tree Hevea Braziliensis that is potentially dangerous

to people who are allergic to it.

Allergy to latex (natural rubber) is now recognised to be an increasing and

clinically important problem. Awareness about it is improving and this knowledge is

important both for health care workers and the general public. The rise in the number

of people becoming sensitised is thought to be due to the increase in the use of latex

gloves since the recognition of the spread of blood-borne viral diseases such as

hepatitis and AIDS. Latex gloves are the conventional means for preventing contact

with body fluids.

New manufacturing methods could also be partly responsible. The increase in

demand for latex gloves resulted in a change in quality during manufacture. Some

gloves now contain more natural latex protein than before and some are pre-powdered

with starch powder, which adsorbs the latex proteins from the gloves and becomes

airborne inducing allergic respiratory problems.

2.1 WHO IS AT RISK?

Both children and adults are affected, and children who have had repeated

surgical operations are particularly at risk. It has been suggested that some babies may

become sensitised when they come into contact with latex gloves at birth. Infants also

come across many articles of clothing, toys and other everyday items that contain

rubber, such as dummies. Any of these could also be sensitising them to latex.

Groups who are particularly at risk include health care workers and people who have

repeated surgery, because of their increased exposure to latex. The condition is most

common in atopic people (people with a tendency to develop allergies). It must be

remembered that people use latex gloves at home to do the washing up.

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2.2 TYPES OF ALLERGIC REACTION

There are two types of allergic reaction to latex. These are known as type-1 and type-

4 reactions

Type-4 is a non-life threatening dermatitis on sites of contact, produced by an allergy

to the chemicals used when processing the rubber. Symptoms include reddening,

itching and swelling of the skin, which develop one or two days after contact.

Type-1 allergy is potentially life threatening. Those affected are sensitive to the

natural proteins in latex. These people may suffer from nasal irritations, urticaria

(hives), asthma and anaphylaxis.

Latex allergy is unusual in that there are more than 12 allergens present in

latex. Allergy commonly involves sensitisation to different latex proteins and patients

are usually sensitive to more than one. Latex allergy is potentially a serious problem

but it can be managed and controlled. If you are sensitive to latex, it is possible you

will react to any latex product and you should try to avoid any articles made from

rubber.

There are numerous everyday items to be avoided, including gloves, balloons,

rubber toys, pencil erasers, latex mattresses and pillows, hot water bottles and some

contraceptives (condoms and the diaphragm). Care should be taken with tyres and

rubber sole shoes, and also with adhesives and self-adhesive envelopes, some of

which contain latex.

Some people with relatively mild latex allergy may be able to use some latex

products. They may also be able to use some brands and not others as different

companies will use varying manufacturing processes that alter the allergenicity of the

latex protein. But even if you are slightly sensitive, it is sensible to avoid contact as

much as possible as with each contact the degree of your allergy and the reaction can

increase. People with severe allergy should not use any latex products.

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The latex-fruit syndrome associated with latex allergy is an important issue.

Some of the proteins present in latex also exist in some fruits and some plants. If a

person is allergic to the protein in latex that is also present in bananas, for example,

they may have a cross-reaction if they eat a banana.

In some cases this works the other way around if you are allergic to bananas,

you may be allergic to the same proteins in latex. The fresh fruits that commonly

cause problems are banana, avocado, kiwi and chestnut and occasionally other foods

including walnut. These three can cause anaphylaxis in a latex allergic person.

Whether you have a type 1 or a type 4 reaction to latex, when you go to a

dentist or a doctor, especially if you are to have an operation, it is essential that yougive information about your latex allergy. Its not just latex gloves that need to be

avoided; latex is also used in catheters, syringes, anaesthetic mouthpieces, elasticated

bandages and protective sheets. There are alternatives that can be used and there are

also alternatives to everyday latex items. For example, non-latex condoms are

available.

There is evidence to suggest that food handlers who wear latex gloves may

contaminate the food with latex allergens and are themselves at risk of developing

latex allergy. It has been demonstrated that when a person with latex allergy eats

cross-contaminated food, it can cause an allergic reaction. There is also a possible risk

from latex adhesives used in food packaging. These are used as cold seal adhesives in

cases where hot seals would damage a product, such as ice cream. There are reports of

people reacting to these adhesives.

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CHAPTER 3

METHODOLOGY

3.1 Basic Latex Formulation

Ingredients

Phr

Amount Needed

(g)Dry Actual

60% High Ammonia Natural Rubber Latex 100 167 500

10% Potassium Hydroxide (KOH) 0.5 5 15

10% Potassium Oleate 0.25

2.5 7.5

50% Sulphur 1.5 3 9

50% ZnO 1 2 6

Table 1 Basic Latex Formulation

This formulation is a common formulation, which has been used as the basic latex

formulations of compounding ingredients.

3.2 Compounding Ingredients

The compounding ingredients is manually prepared which means by weighing

the chemicals in the form of powder which the weigh is calculated as shown in the

sample of calculation below. All chemical ingredients are prepared by blending the

mixture using Pebble Mills to grind the chemicals into a uniform particles size for

ease of the compounding process. The particles size is crucial to be same to prevent

any coagulation and premature vulcanising process, which will totally damage the

mixture.

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Example of calculation to determine the actual weight of the ingredients.

Accelerators e.g. Mercaptobenzothiazoles (MBT)

Amount to be prepared = 500 g

Part by Weight

MBT 50

Dispersing Agent 1

Bentonite Clay 1

Soft Water 48

Total 100

500 / 100 = 2 (factor)

Actual weight can be calculate by multiplying the Part By Weight value with the

factor

Example:

MBT

50 x 2 = 100 g (the amount of MBT in the forms of powder needed to be weight)

Figure 1 Preparation of compounding ingredients by using Pebble Mill

The duration requires in the process of milling the chemical ingredients is

totally depending on the type of ingredients to be mill. For instance, in producing 50%of sulphur dispersion, the mixture needs to be mill for about 48 hours.

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After that, the mixture will undergo a dispersion test where a drop of the

mixture is dropped into a cylindrical tube filled with water so that the dispersion of

the chemicals particle can be observed.

This test is crucial to determine whether the particle size of the chemical is

well milled. If the particle is dropping abruptly after it is tested in the tube, the milling

time will needed to be extend until the particle size is well balance. If the unbalanced

of particle size which consist in the chemicals are to be mix with the latex,

coagulation of the mixture will initiates and the result will be totally invalid. Worse,

the mixture will undergo a rapid curing phase where the mixture cannot be used to

produce any products anymore.

Table 1.2 showing the chemical ingredients that will be mix with the latex by the

NAME FORM

Potassium Oleate 10% aqueous solution

Potassium Hydroxide (KOH) 10% aqueous solution

Sulphur 50% dispersion

Zinc Oxide (ZnO) 50% dispersion

ZDEC 50% dispersionMBT 50% dispersion

Table 2 Chemical Ingredients

All the chemical ingredients are prepared in 50% dispersion with the

exception of foaming agent, Potassium Oleate and Potassium Hydroxide (KOH).

Although the dispersion value is the same, the amount that we use is still base on the

recipe, which is shown in the table 2.4 below.

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The recipe, which has been used, is shown in table 2.4

Ingredients/Recipe 1st (control) 2nd 3rd 4th 5th

Dry/Actual Dry Actual Dry Actual Dry Actual Dry Actual Dry Actual

50% ZDEC 1 0.5 0.25 2 -

50% MBT - 0.5 0.25 2 1

Table 3 Formulations / recipe with different accelerator amount

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3.3 Latex Testing

Before the latex can be mix with processing ingredients, it has to be tested to

measure the stability and to determine whether it is suitable to be used in

manufacturing products.

These test are:

1. TSC, Total Solid Content

2. DRC, Dry Rubber Content

3. Alkalinity Test

4. Viscosity Test

1. Total Solid Content ISO 124 1974 (E)

Total solid content can be defined as the percentage weight of latex which is

non-volatile at the given temperature in an open atmosphere and is therefore a

measurement of the total rubber and non-rubber solid in the latex itself.

Calculation of Total Solid Content:

TSC = M1 / M0 X 100

Where;

M0 is the mass in gram of the test portionsM1 is the mass in grams of the dried sheet

The result of duplicate determinations shall not differs by more than 0.2 unit

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2. Dry Rubber Content ISO 126 1972

The dry rubber content is the percentage weight of latex, which coagulable by acetic

acid under closely defined conditions. The difference between TSC and DRC

represents the soluble non-rubber solids content.

Calculation of dry rubber content

DRC = M1 / M0 X 100

Where;

M0 is the mass in gram of the test portions

M1 is the mass in grams of the dried sheet

The procedure is to be triplicate and the results should agree within 0.2% m/m DRC

3. Alkalinity Test ISO 125 1974 (E)

Alkalinity refers to the total amount of alkali present in the latex and is often

expressed as the amount of added ammonia in the latex.

Calculation of alkalinity

Alkalinity (As NH3) = F1 x c x v

m

Where:

F1 is the factor, 1.7 for hydrochloric acid and 3.4 for sulphuric acid.

C is the actual concentration, expressed in moles of HCL or H2SO4 per-cubic

decimetre of acid used.

V1 is the volume, in cubic centimetres of acid used

m is the mass in grams of the test portions

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The result of the duplicate determination should not be differ more than 0.02

unit where the actual alkalinity is above 0.5 unit or shall not differ by more than 0.01

unit where the actual alkalinity is 0.5 unit or less.

4. Viscosity test Brookfield Viscometer

The viscosity of latex can determine the performance of the latex during

processing. The viscosity of latex is variable and therefore is determined at 60.0

0.1% total solid content at various rates of shear at 25C by using Brookfield

Viscometer. The viscosity in centipoises is calculated by multiplying the dial readings

by the various spindles.

Figure 2 Viscosity Testing

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Viscosity Testing

Viscosity testing is measured the torque required to rotate an immersed

element (the spindle) in latex by using a multiple speed transmission and spindle

chosen. In this testing for latex the suitable spindle is spindle no.2.

Procedure:

1. Stir the latex in beaker until it can able to flow.

2. Then, remove bubble from the surface of the latex with a piece of filter paper.

3. Attach Guard and spindle no.2 to the viscometer.

4. Level the viscometer and lower the spindle into latex until the surface of the

latex is level with the groove marked on the spindle. The spindle should be

placed at the centre of the beaker. Check the level of the viscometer again.

5. Select speed at 3rpm, depress clutch and switch motor on.

6. Release clutch and allow dial to rotate until a steady reading is obtained.

7. To take a reading, depress the clutch and switch of the motor.

8. The clutch is released only after reading is taken.

9. The Brookfield viscosity in centipoises is calculated by multiplying the dial

readings by the factors for various spindles.

The formula of calculating viscosity is based on the spindle number, which is used to

measure the viscosity of latex.

Viscosity = Dial Readings x Factor

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Figure 3: Casting mould for dumbbells sample

Matured

In matured, the step is not that different compared to cured except that there is

no involvement of water bath. The sample is mixed with all of the compounding

ingredients and then is left in room temperature for approximately 14 days before it is

poured into the mould. The mixture in the beaker needs to be sealed with aluminium

foil to prevent the water and ammonia, which presents in the latex vaporized to the

atmosphere.

During the period, viscosity test is run on the mixture in 3 days interval to

determine the changes which may occur during the maturing period. After 14 days,

the mixture will then be poured into the mould and be left again for about 3 days to

get the rubber sheets before the dumbbells sample can be produce with the profile

cutter.

Sampling

After the sample has finally been produced, it will undergo cutting process

using the profile cutter to get the dumbbells sample. After the samples h

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Tensile testing is a measurement of the ability of latex to withstand forces that

tend to pull it part and determine to what extent the latex stretches before it breaking.

Procedure:

First the sample of latex cut into the dumbbell to easy used equipment testing.

Position the test specimen vertically in the grips of the testing machine.

Before put the sample on the grip need to measure width and thickness.

Tighten the grips evenly and firmly to prevent any slippage.

Set the speed of testing at proper rate and start the machine.

As the specimen elongates, the resistance of the specimen increased and is

detected by a load cell.

The load value (force) is record by the instrument.

The elongation of the specimen is continued until a rupture of the specimen is

observed.

The tensile strength at yield and at break (ultimate tensile strength) is

calculated.

The tensile modulus and elongation value are derived from the stress-strain

curve.

Study characteristic features of the stress and strain cue for the respective

materials.

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CHAPTER 4

RESULTS AND DISCUSSION

4.1 LATEX TESTING

DATA SHEET

TOTAL SOLID CONTENT

TSC = M1 / M0 X 100

Where;




Total Solid Content

Sample A

Mass before drying of sample A = 2.02g (M0)

Mass of dried portion after drying at 70C = 1.228g (M1)

Total solid content = M1 / M0 X 100

1.228/2.02 X 100 = 60.79%

Sample B

Mass before drying of sample B = 2.041g (M0)


Total Solid Content = M1 / M0 X 100

1.244/2.041 X 100 = 60.95%

The difference of duplicated sample

60.95% - 60.79% = 0.16 < 0.2

Discussion

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From this test, the result indicated that the latex, which will be use for

compounding, is suitable to be use because the percentage of the total solid content,

which presents in the latex, is ranges from about 60.8 to 61%.

DRY RUBBER CONTENT


DRC = M1 / M0 X 100

Where;



The procedure is to be triplicate and the results should agree within 0.2% m/m

DRC

Data Sheet

Sample A

Dry Rubber Content = M1 / M0 X 100

6.008/10.119 X 100 = 59.37%

Sample B


6.006/10.118 X 100 = 59.36%

The difference of duplicated result = 59.37-59.36 = 0.01 < 0.02

For dry rubber content, usually the result is ranges from 59-60. The latex, which is

tested, has been used before so the content has been exposed to the atmosphere which

causing the result to be exceptionally low.

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ALKALINITY TEST

Result of titration

Volume of 1st titration = 18.3cm

Volume of 2nd titration = 18.0cm

Average = 18.153cm

Alkalinity = 170 x N x V x / m(100-TSC)

TSC average = 60.95+60.79 / 2

= 60.87%

1st

titrationAlkalinity = 170 x 0.05 x 18.3 / 4.456(100-60.87)

= 155.55/174.36

= 0.89

2nd titration

Alkalinity = 170 x 0.05 x 18.0 / 4.294(100-60.87)

= 153/168.02

= 0.91

The difference of duplicated result = 0.91-0.89

= 0.02

VISCOSITY TEST

Result

Spindle

Number

Viscosity in centipoises (mPas) Dial Reading x Factor

6 30 60

1 600 - -

2 625 280 197.5

3 600 300 220

4 500 300 250

Table 5: Viscosity Test Result

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4.2 TENSILE TESTING

In this project, the machine which is use to determine the mechanical

properties of the rubber material is Lloyd tensile tester. For each recipe, the sample

that are to be tested is in the multiply of 5 samples. From all five compounding recipe

which has been used, only three compounding ingredients are manage to be used to

produce sample which is the 1st, 2nd and 3rd recipe. The 4th and 5th recipe failed to be

used due to certain occurrences that will be briefly discuss afterward.

RESULT

Machine parameters

Test Speed 500.00 mm/s

Gauge Length 20.000 mm

Width 6.000 mm

Temperature 23C

Humidity 60

Table 6: Tensile Test Parameter Setting

Cured sample

Discussion

1st recipe

The table above shows the value of tensile strength and ultimate elongation of

the 1st recipe for cured sample. From all five samples, the 1st sample is the ones

produced the highest value of tensile strength and ultimate elongation; 7.4037 Mpa

and 3895.5 mm.

The 1st recipe did not include mercaptobenzothiazole (MBT) as the accelerator

because the 1st recipe is utilized as the control formulation. However this recipe is

mixed with 1 pphr of Zinc-Diethyldithiocarbamate (ZDEC).

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3rd recipe

Discussion

For the 3rd recipe, the 5th sample showing the highest value of tensile strength

including the ultimate elongation; 15765000 N/m, 3128.6 mm. The amount of

accelerator used in this recipe is the same as the 3rd recipe for the cured sample; 0.25

for MBT and 0.25 for ZDEC.

Conclusion

Cured Sample

From all 15 samples from three different recipes, which contain different

combination of accelerator amount, it is clear that the 3rd recipe has the ability of

producing the greatest mechanical properties exceeding the other two recipes. For the

1st recipe, the average value of tensile strength and ultimate elongation is 6.775 MPa

and 3405.9 mm for the ultimate elongation.

For the 2nd recipe, the value of tensile strength is 18.827 MPa and 3691.5 mm

for the ultimate elongation. Last but not least, the value of tensile strength and

ultimate elongation of the 3rd sample is 21.267 MPa and 3691.5 mm. From all three

recipes, it is proven that the 3rd recipe has the greatest mechanical properties in which

the amount of chemicals especially accelerator which is used in the compounding

ingredients is relatively low, 0.25:0.25 pphr.

Graph o Stress Vs. Elongation

-5

0

5

10

15

20

25

0 500 1000 1500 2000 2500 3000 3500 4000

Elongation (mm)

St

ress(MPa)

Graph 1 Recipe 1 Graph 4 Recipe 2 Graph 3 Recipe 3

Figure 6: Cured Graph

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The graph above is produced base on the results from testing the samples,

which is from three different recipes. The graph is produced with the data which

having the highest value of tensile strength and elongation. For this graph, it shows

the properties of cured sample from the three recipes. It can be seen that from all three

recipes, the 3rd recipe has the greatest mechanical properties in terms of its tensile

strength and ultimate elongation.

Conclusion

Matured Sample

Graph of Stress Vs. Ultimate Elongation

0

5

10

15

20

0 500 1000 1500 2000 2500 3000 3500

Ultimate Elongation (mm)

Stress(MPa)

Graph 1 Recipe 1 Graph 1 Recipe 2 Graph 5 Recipe 3

Figure 7: Matured Graph

For all the matured samples from three recipes that have been tested by using

the Lloyd tensile tester, it can be seen that there are a little differences regarding the

tensile strength and ultimate elongation values between the 1st and the 3rd recipe. For

the 1st recipe, the average value of ultimate elongation is 3405.9 mm, which is bigger

than the value produced by the 3 rd, which is 3035.8 mm. However the value of tensile

strength of the 3rd recipe exceeded the value of the 1st formulation, which is 13663200

N/m for the 3rd and 11572200 N/m.

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4.3 SAMPLE FAILURES

Cured and Matured sample of 4th and 5th recipe

In this experiment, there are total of 5 compounding recipes, which have been

formulated. These entire 5 recipes differs from one and another in terms of their ratio

or the amount of the accelerator which is mixed with the latex along with other

chemicals such as activator, dispersion agent etc. During the experiment of producing

the cured and matured sample, the 4th and 5th recipe failed and the mixture cannot be

use to produce samples because the mixture abruptly coagulates during the

experiment.

Such occurrences maybe because the amount of accelerator, which is mixed in

the latex is too high. For the 4th recipe, the amount of MBT and ZDEC used is both

relatively high; 2 pphr for both of the chemicals. This amount of accelerator used

affected the mixing process of the latex because it has accelerated the cross-linking

process at a very fast rate. This makes the mixture to harden and coagulum is

produced and directly damaging the compound.

Figure 8: Failed Cured Sample

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Figure 9: Failed Sample During Casting Process

Figure 10: Failed Matured Sample

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Comparison

Graph Of Cured Vs. Matured

0

5

10

15

20

25

0 500 1000 1500 2000 2500 3000 3500 4000

Ultimate Elongation (mm)

Stress(MPa)

Cured Matured

Figure 11: Cured Vs. Matured

From all three recipes, only the 1st and the 3rd recipe manage to produce the

greatest results, which also proved its properties. So referring to the graph above, it

shows the comparison in terms of tensile strength and ultimate elongation for both

cured and matured sample. Looking at the graph, it is proven that producing samplesby cured method is much more efficient because it has better properties compared to

matured. Plus, by using cured method to produce sample, it is faster and this is

because there is no need to leave the mixture up to 2 weeks just for the mixture to

completely vulcanize.

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CHAPTER 5

RECCOMENDATION

From these project, the results conclude that MBT and ZDEC (accelerator)

which is used in the production of latex gloves need to be include in order to produce

products with a good mechanical properties which is crucial to act as a barrier of

protection both for the health care worker and the patient to guard against contact with

blood, other body fluids, and microorganisms.

The used of MBT need to be put a very serious consideration because the

higher the amount of MBT, which is added during compounding, the higher the risk

for the allergic reaction to occurs. MBT can be considered as the agent, which will

activate the reaction, in which will produce the protein, which is the cause of the

allergic reaction to occur. Despite of the allergic reaction that related to the amount,

which is used in compounding, from the experiment, the excessive usage of MBT

could also reduced the properties of the product.

This is because, if the amount is to high, the mixture will tend to produce

coagulum and will directly affect the process of stirring the mixture because it will

harden. This is because, the higher the amount of accelerator added to the latex, the

process of cross-linking will be much higher in terms of its rate of reaction. If the

reaction happens in such a very fast rate, premature vulcanization will happen.

REFERENCE

1) Lecture notes by Ms. Mazlina Bt. Ghazali

2) Internet

www.aspan.org

International Rubber Research & Development Board

www.iirdb.net

www.rrim.com

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http://www.aspan.org/http://www.iirdb.net/http://www.rrim.com/http://www.aspan.org/http://www.iirdb.net/http://www.rrim.com/


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APPENDIX A

DATA SHEET AND CALCULATIONS

1. LATEX TESTING

1.1 TOTAL SOLID CONTENT

TSC = M1 / M0 X 100

Where;




Data Sheet

Mass of Petri dish + cover A = 98.34gMass of Petri dish + cover B = 97.30g

Before Drying

Mass of sample A (M0)A = 2.02g

Mass of sample B (M0)B = 2.04g

After Drying

Mass of sample A without Petri dish = 1.228gMass of sample B without Petri dish = 1.244g

Total Solid Content

Sample A

Mass before drying of sample A = 2.02g (M0)


Total solid content = M1 / M0 X 100

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1.228/2.02 X 100 = 60.79%

APPENDIX B

Sample B

Mass before drying of sample B = 2.041g (M0)Mass of dried portion after drying at 70C = 1.244g (M1)

Total Solid Content = M1 / M0 X 100

1.244/2.041 X 100 = 60.95%

The difference of duplicated sample

60.95% - 60.79% = 0.16 < 0.2

1.2 DRY RUBBER CONTENT


DRC = M1 / M0 X 100

Where;



The procedure is to be triplicate and the results should agree within 0.2% m/m DRC

Data Sheet

Sample A

Mass of Petri dish A = 93.51g

Mass of Petri dish A + latex = 103.63g

Before drying

Mass of latex A = 10.119g

After Drying

Mass of latex A = 6.008g (M1)


6.008/10.119 X 100 = 59.37%

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APPENDIX C

Sample B

Mass of Petri dish B = 93.92g

Mass of Petri dish B + latex = 104.04g

Before drying

Mass of latex B = 10.118g

After Drying

Mass of latex B = 6.006g (M)


6.006/10.118 X 100 = 59.36%

The difference of duplicated result = 59.37-59.36 = 0.01 < 0.02

For dry rubber content, usually the result is ranges from 59-60. The latex, which is

tested, has been used before so the content has been exposed to the atmosphere which

causing the result to be exceptionally low.

1.3 ALKALINITY TEST

Data Sheet

Sample A

Weight of an empty weighing bottle = 41.343g

Weight of weighing bottle + latex = 46.566g

After pouring

Weight of weighing bottle = 42.110g

Weight of latex used = 46.566-42.110

= 4.456gSample B

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APPENDIX D

Weight of an empty weighing bottle = 42.389g

Weight of weighing bottle + latex = 47.558g

Sample B

After pouring

Weight of weighing bottle = 43.264g

Weight of latex used = 47.558-43.264

= 4.294g

Result of titration

Volume of 1st titration = 18.3cm

Volume of 2nd titration = 18.0cm

Average = 18.153cm

Alkalinity = 170 x N x V x / m (100-TSC)

TSC average = 60.95+60.79 / 2

= 60.87%

1st titration

Alkalinity = 170 x 0.05 x 18.3 / 4.456(100-60.87)

= 155.55/174.36

= 0.89

2nd titration

Alkalinity = 170 x 0.05 x 18.0 / 4.294(100-60.87)

= 153/168.02

= 0.91

The difference of duplicated result = 0.91-0.89

= 0.02

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APPENDIX E

1.4 TENSILE TESTING

RESULT

Machine parameters

Test Speed 500.00 mm/s

Gauge Length 20.000 mm

Width 6.000 mm

Temperature 23C

Humidity 60

Cured sample

1st recipe

Sample No Tensile Strength (MPa) Ultimate Elongation

1 7.4037 3895.5

2 6.1595 3780.5

3 6.7209 3828.6

4 6.1361 3632.3

5 7.4548 3832.6

Average 6.7750 3793.9

2nd recipe

Sample No Tensile Strength (MPa) Ultimate Elongation

1 18.644 3301.92 20.863 3266.8

3 17.358 3267.9

4 21.175 3469.0

5 16.093 3214.9

Average 18.827 3304.1

APPENDIX F

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3rd recipe

Sample No Tensile Strength (Mpa) Ultimate Elongation

1 22.250 3661.8

2 22.787 3789.1

3 23.664 3936.0

4 18.145 3409.1

5 21.291 3661.6

Average 21.627 3691.5

Matured Sample

1st recipe

Sample No Tensile Strength (N/m) Ultimate Elongation

1 18911000 3636.6

2 16285000 3566.7

3 15865000 3472.0

4 14834000 3276.8

5 11966000 3077.6

Average 11572200 3405.9

2nd recipe

Sample No Tensile Strength (N/m) Ultimate Elongation

1 10216000 2863.3

2 9134500 2704.03 7325500 2314.2

4 10437000 2703.5

5 9703000 2549.6

Average 9363200 2626.9

APPENDIX G

3rd recipe

Sample No Tensile Strength (N/m) Ultimate Elongation1 14224000 3106.9

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2 13477000 2977.6

3 12466000 2872.2

4 12384000 3093.8

5 15765000 3128.6

Average 13663200 3035.8

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APPENDIX H

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APPPENDIX I

Brookfield

Viscometer

Casting Mould

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Cured Sample in Water Bath

Mechanical Stirrer

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Pebble Mill

Failed Cured Sample in water Bath

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Lloyd Tensile Tester

Final Year Project Content

Documents