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Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman, National Center for Radiation Research and Technology Atomic Energy Authority Cairo, Egypt

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Page 1: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

Radiation Processing of Natural

and Synthetic Polymers for

Potential Applications El-Sayed A. Hegazy

Former Chairman, National Center for

Radiation Research

and Technology

Atomic Energy Authority

Cairo, Egypt

Page 2: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

2

OBJECTIVE:

To study the effect of ionizing radiations on

the crosslinking and degradation of some

natural polymers such as CMC-Na, chitosan

and alginate. Super absorbant materials

and nano gels were prepared by radiation

copolymerization of natural and synthetic

polymers for possible use in industrial,

agricultural and biomedical applications.

Page 3: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

3

CMC Concentration (%)

Gel

Co

nte

nt

(%)

0

5

10

15

20

25

10 20 30 40 50 60 70 80 90

Effect of different CMC concentrations in water on its gel content at 20 kGy using

EB irradiation in air atmosphere.

Page 4: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

4

Gel content (%) of cross linked CMC-Na as a function

of irradiation dose at 35 oC.

Irradiation Dose (kGy)

0 5 10 15 20 25

Gel

Co

nte

nt

(%)

0

5

10

15

20

25

30

35

30%CMC-Na

40%CMC-Na

50%CMC-Na

Page 5: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

5

Effect of applied irradiation dose on the swelling ratio of

crosslinked CMC-Na in distilled water (50 wt%).

Time (min.)

0 10 20 30 40

Sw

elli

ng

Rat

io (

g/g)

0

20

40

60

80

100

120

140

160

18020kGy.

30kGy.

40kGy.

Page 6: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

6

Effect of irradiation dose on the degradation of chitosan in the presence and

absence of additives

Irradiation Dose ( kGy )

0 20 40 60 80 100 120 140 160 180 200

Ch

ito

san

Mo

lecu

lar W

eig

ht

x 1

06

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

Blank

With 10% H2O2 ( v / w )

With 20% H2O2 ( v/ w)

With 10% KPS ( w / w )

With 10% APS ( w / w )

Page 7: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

7

Effect of irradiation on the degradation of Na-alginate

in the presence and absence of additives.

Irradiation Dose ( kGy )

0 20 40 60 80 100 120 140 160 180 200

So

d. A

lgin

ate

Mo

lecu

lar W

eig

ht

x 1

04

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

Blank

With 10% H2O2 ( v / w )

With 20% H2O2 ( v / w )

With 10% KPS ( w / w )

With 10% APS ( w / w )

Page 8: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

8

Use of Degraded Natural polymers in

agriculture as a growth promoter

Degraded Na-alginate and chitosan could be used as a growth promoter for plants in agriculture purposes. The growth and other responses of zea maze plant treated with irradiated Na-alginate or chitosan of different MWts were studied.

The test field results showed that the treatment of the zea plant with irradiated Na-alginate at 120, 160, and 200 kGy in the presence of APS resulted in increasing the growth in plant. Meanwhile, the use of chitosan under the same conditions enhances the plant growth and productivity as well.

The increase in plant performance by using degraded alginate or chitosan suggested its acceptable use in agriculture field as growth promoter.

Page 9: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

9

The growth and other responses of zea maze plant treated with

irradiated Na-alginate of different MWts in APS

20

kGy 200 kGy 160 kGy 120 kGy 80

kGy

0

Contro

l

SA Treated by 10% APS

40

kGy

Page 10: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

10

Radiation Cross-linking of Natural Products/

PAAm For the Use as Super Adsorbent

Hydrogels

Super Adsorbent Hydrogels are used in

various fields including bandages and wound

dressing, controlled drug delivery, humidity-

controlled products, soil conditioners,

controlled release of fertilizers, aqueous

waste management and gelling agents,

medical health care products..etc.

Page 11: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

11

Gel content of crosslinked CMC-Na:PAAm as a function of

irradiation dose extracted at 50oC after 24hr.

Irradiation Dose (kGy)

0 5 10 15 20 25

Gel

Con

ten

t (%

)

0

10

20

30

40

50

60

70

80

50:50

60:40

70:30

80:20

CMC-Na:PAAm

Page 12: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

12

Effect of polymer composition on the swelling ratio of crosslinked

CMC-Na:PAAm hydrogel, Polym. conc. 30 wt%. Irrad. dose 10kGy

Time (min)

0 5 10 15 20 25 60

Sw

elli

ng

Ra

te (

g/g

)

0

50

100

150

200

250

70/30

60/40

50/50

80/20

0/100

CMC-Na/PAAm

Page 13: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

13

Time(min.)

0 5 10 15 20 25

Sw

ell

ing R

ati

o (

g/g

)

0

50

100

150

200

with blowing agent

without blowing agent

Swelling ratio of CMC-Na:PAAm hydrogels (50:50) in distilled

water.Polym.conc. 30 wt% Irrad. dose 10kGy in Am Carbonate.

Page 14: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

14

Bean plant cultivated in soil after 9 weeks:

(A) Untreated (control), (B) Treated with PAAm and (C) treated

with PAAm/Na-alginate.

Page 15: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

15

Swelling ratio of CMC-Na/PAAm superabsorbent hydrogel and

commercial diaper in simulated urine solution.

Time (min.)

0 5 10 15 20 25 30

Sw

ell

ing

Ra

tio

(g

/g)

0

10

20

30

40

5050:50 (CMC-Na:PAAm)

commercial diapers

Page 16: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

16

Application of PNIPAAm grafted with

some natural polymers

Effect of natural polymer on the release of ketoprofen from its

corresponding copolymer with PNIPAAm at pH 1 and 7.

Page 17: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

Radiation synthesis of nano-

sized hydrogel particles based

on the interpolymer

complexation between

polyvinylpyrrolidone and

polyacrylic acid by gamma

radiation

Page 18: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

DLS Results of

irradiated (40 kGy)

PVP/PAAC

(a) pH 4

(b) pH 7

Volume-weighted Gaussian distribution analysis for irradiated (40 kGy)

PVP/PAAC at pH 4 and 7. Feed composition: PVP/PAAc (35/65 mol/mol

%); total conc. 0.5%; PVP 1300000.

Dav=280 nm

PDI=0.176

Dav=200 nm

PDI=0.165

Synthesis of PVP/PAAc nanogels by

gamma irradiation in air atmosphere:

Page 19: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

Figure (3) AFM image for PVP and PAAc

polymers

Multimodal

distribution

for the

particles

obtained

from PVP/

PAAc

polymers

Page 20: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

DLS results for system (B): PVP/AAc in deionized water at pH 4.

PVP/AAc: 35/65 mol/mol %; Total conc.: 1.5%; PVP Mw = 1300000;

20 kGy.

DLS results for

PVP/AAc aqueous

solution at pH 4

Dav=83 nm

PDI=0.041

Page 21: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

DLS results for

N-VP/PAAc aqueous solution

at pH 4

DLS results for system (C): N-VP/PAAc in deionized water at pH 4.

N-VP/PAAc: 35/65 mol/mol %; Total conc.: 1.5%; PAAc Mw = 497000; 20

kGy.

Dav=57 nm

PDI=0.086

Page 22: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

AFM image (topography and three dimensional) of PVP/PAAc nanogel

particles investigated in deionized water.

Page 23: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

Possible Bio-medical

Applications of PVP/PAAc

Nanogels

Page 24: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

Treatment of dry eye syndrome

Topical application of PVP/PAAc nanogel

dispersions in an experimental dry eye

model in albino rabbits

Dry eye syndrome is a

chronic eye disease which

is associated with

symptoms of discomfort,

visual disturbance and

abnormal tear film from

either tear deficiency or

excessive tear evaporation

Page 25: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

Topical application of PVP/PAAc

nanogel dispersions in an experimental

dry eye model in albino rabbits

An experimental dry eye model in albino rabbits was

carried out using atropine sulfate 1% eye drops

The model produces some typical dry eye symptoms

such as a significant reduction in the tear volume and

tear break-up time (TBUT), corneal staining, and

histopathological signs of dryness and inflammation.

The prepared PVP/PAAc nanogels (1.5 w/v%, pH 7.4)

were used for the treatment of the dry eye model, and

the obtained results were compared with that of

commercial carbomer gel “Vidisic, 0.2%”

Page 26: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

Untreated dry eye model

Ulcer

Page 27: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

Treated dry eye model

Page 28: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

28

Conclusion

It can be concluded that radiation is a very

effective tool for controlling the degradation and

cross-linking of natural occurring polymers and

the synthesis of relative economic,

environmentally friendly super-absorbent

hydrogels which may potentially be used in

personal care products industry, in agriculture

as a growth promoter, and in medical uses as

drug delivery under control release to specific

sites.

Page 29: Radiation Processing of Natural and Synthetic Polymers for ... · Radiation Processing of Natural and Synthetic Polymers for Potential Applications El-Sayed A. Hegazy Former Chairman,

29

Many Thanks

for your kind attention