This document outlines the preparation of a poly acrylate binder for pigment printing. It discusses selecting monomers like butyl acrylate, ethyl acrylate, and methyl methacrylate. A recipe is provided using these monomers along with acrylic acid and N-hydroxymethyl acrylamide. The procedure for emulsion polymerization is described in 7 steps, beginning with emulsifying the monomers and ending with drying the purified polymer. The calculated glass transition temperature of the polymer is 180°C, making it suitable for use as a pigment printing binder.
5. Objectives
The aim of our task is to synthesize a good quality of
binder which can be used for pigment printing process.
6. Binder
Binders plays key role in pigment printing. Binder are monomers
which on heating get converted into polymers. Just by simple heating, no
pressure , no steaming , no electricity.
Binder actually hold the pigment color and sandwich it between fabric
surface and plastic coating and this coating help color to stick there and
stand with high and severe conditions.
In addition to binder an other component is also added to the textile
pigment printing paste and that is called fixer. Fixers are mostly
formaldehyde based, which helps in strengthening of binder to hold on
pigment.
7. Properties of Pigment Printing binder
Binder should be soft, good film, high strength, good elasticity,
excellent wash ability, strong adhesion, light color, excellent
transparency, excellent light fast ness, low cost and easy to implement
production etc.
The softness and strength of the binder film can be adjusted according
to the ratio of soft and hard monomers.
Physical appearance should be transparent
pH should be 7 to 8. And Cons. 33% ± 1% polymer contains & 38%
± 1% Solids.
Good resistant ability to solvent.
Good rubbing fastness (wet & dry)
8. Selection of Monomers
1. Butyl acrylate:
Properties:
1)Soft monomer,
2) Tg is -570
C
3)Good elasticity,
4)Excellent Softness,
5)Good resistant to solvents,
6)Excellent heat resistance,
7)Good wet rub fastness,
8)Poor dry rub fastness.
9. Selection of Monomers
2. Ethyl Acrylate
Properties:
1)Soft monomer,
2) Tg is -240
C
3)Good elasticity,
4)Excellent Softness,
5)Good resistant to solvents,
6)Excellent heat resistance,
7)Poor wet rub fastness,
8)Good dry rub fastness.
10. Selection of Monomers
3. Methyl Methacrylate:
Properties:
Hard monomer
Tg is 1050
C,
Good elasticity,
Moderate softness,
Excellent heat resistance,
Good dry rub fastness,
Poor wet rub fastness.
H2C
CH3
O
O
CH3
11. Selection of Monomers
4. Styrene:
Properties:
1) Hard monomer
2)Tg is 1000
C,
3)Poor elasticity,
4)Poor softness,
5)Good dry rub fastness.
6)Good wet rub fastness
12. Selection of Monomers
5. N-hydroxymethyl Acrylamide:
Properties:
1)Cross linking monomer,
2)Helps to increase the fastness,
3)Cross linked between both fibres
& the monomers
13. Selection of Monomers
6. Acrylic Acid:
Properties:
1) Functional monomer,
2) Makes bond with cross linked monomers
14. Recipe
Materials Amount of chem. Percentage(%)
Ethyl Acrylate (EA) 7.5 gm. 15%
Styrene (ST) 7.5 gm. 15%
Methyl Methacrylate 16 gm. 32%
Butyl Acrylate (BA) 17 gm. 34%
Acrylic Acid (AA) 1 gm. 2%
N- Hydroxy Methyl Acrylamide 1 gm. 2%
Total 50 gm. 100 %
Ammonium per sulphate(APS) 0.25 gm. 0.5% of total monomer
Alkyl phenol ethoxylates OP-10
Sodium dodecyl sulphate K-12
1 gm.
0.5 gm.
4% of total monomer
Ammonium water(20% ) As required Until pH is 7
Soft water 120.75 70 % of total material
15. Calculation of Tg of Polymer
Equation:
Where,
W1,W2,W3……Wn are weight of respective monomer &
Tg1,Tg2,Tg3……Tgn are glass transition temperature of respective monomer.
3
1 3
n1 2
2
1
gg g g ng
WW W
T T T T
W
T
= + + ……++
16. Calculation of Tg of Polymer
The calculated Tg of our Poly Acrylate binder is 180
C/ 291 K.
During the calculation we omitted two functional group because of
their little amount in synthesizing of polymer.
The range of Balanced Tg is---
10 ≤ Tg ≤ 25
That means our resultant polymer will be in balanced condition.
17. Procedure
Step I → Emulsify the monomer with surfactants at room temperature.
Take OP-10 and K-12, then add 20% of total water and put all the
monomer one by one at 5 minutes of time interval. Then run about 30
minutes at room temperature with continuous stirring.
Step II → Make the solution of Initiators. Add 0.25 gms of Ammonia
per sulphate in 20 ml of water.
Step III → Take 1/6 parts pre-emulsion in a 3 neck bottle; add
remaining 80% of total water, then raises the temp. With continuous
stirring. At temp 75˚C, add 1/3 parts of initiators in the pre-emulsion
solutions and run about 20 minutes. Continue the process till for
observing the blue beam in mixtures solutions.
Step IV → When blue beam observed then remaining 5/6 parts of pre-
emulsion and 2/3 parts of initiators put into the reactor simultaneously
one by one in 90 minutes of time intervals at 80˚C temp.
18. Step V → Increase the temp from 80˚C to 85˚C and keep it about 30
minutes. Stirring speed should be slower. Run the process till for
observing sweet smell. (Note: If sweet smell not found or strong smell
observed then add 10% extra initiators to the mixtures. Need to run
another 20 min. at 85˚C.).
Step VI → When sweet smell is observed, lower the temperature at
40˚C.Nuetralize the solutions by adding ammonia water (20%) to the
solutions mixtures until PH=7 is not achieved.
Step VII → Lower the temperature of the solution to room temperature
and collect all the segments and residue by filtration. Wash the entire
residue and dry it at 105˚C for 90 minutes.
19. Design summarization
This design we have to understand the emulsion polymerization
technique by using soft, hard and functional monomers. Also our
realization is that, emulsion polymerization is a type of radical
polymerization that usually starts with an emulsion incorporating water,
monomer, and surfactant. With increasing proportion of monomers in the
formulation which could be due to the lower reactivity of monomers for
radical polymerization in the presence of these others monomers. More
study for the utilization of monomers in polymer synthesis is needed
which, on successful optimization, would give a cost-effective
alternative to various commercial areas.