EFFECT OF PLASTICIZERS ON CHARACTERISTIC OF BACTERIAL CELLULOSE-ALGINATE-GELATIN

COMPOSITE FILMS

PRESENT BY: SUTASINEE SEETABHAWANG

Department of Chemical Engineering, Faculty of Engineering,

Chulalongkorn University, Thailand

ADVISOR : ASSOC.PROF. MUENDUEN PHISALAPHONG, Ph.D.

BACKGROUND

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In order to overcome the problem associated with brittle films after drying, plasticizers

are used to improve the film’s properties.

Biodegradable films for food packaging have attracted and interested because they

could enhance food quality and reduce pollution of traditional plastic films.

The addition of plasticizer can reduce inter-chain interactions, increase film flexibility,

reduce brittleness and prevent the shrinkage of the films.

3

1. To develop composite films from the blends of bacterial cellulose (BC), alginate (A) and

gelatin (G), we called “BC/A/G”

OBJECTIVES

2. To investigate the effects of the blend composition and type of plasticizer on the film

characteristics

3. To determine the physical, chemical and mechanical properties of the films for further

application of packaging materials

INTRODUCTION

1. BACTERIAL CELLULOSE (BC)

BC is a linear polysaccharide of glucose.

(Brown, 1996)4

It can be biosynthesized by Acetobacter xylinum.

PROPERTIES OF BC

INTRODUCTION

Strength

High purity (~99.9% cellulose)

High water holding capacity

Superior water resistance

High mechanical strength

5

(Chiaoprakobkij et al., 2011; Brown, 1992; White et al., 1989)

Weakness

Poor ability of rehydration after drying due to its high crystallinity

INTRODUCTION

6

A is a linear polysaccharide copolymer of (1-4)-linked β-D-mannuronic acid (M) and

α-L-guluronic acid (G) monomers.

2. SODIUM ALGINATE (A)

(Pinto Cruz et al., 2004, modified)

It can be isolated from algae and seaweed.

PROPERTIES OF A

INTRODUCTION

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Properties Well-characterized hydrogel forming Water resistance and high mechanical properties

when crosslinked by divalent cations such as CaCl2

Thickener and Stabilizer agent

Non-toxicity

INTRODUCTION

3. GELATIN (G)

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G is a water soluble protein.

(Peña et al., 2010)

Solubility at temp. > 45˚C

It is a thermo-reversible structure.

Setting at temp. < 30 ˚C

PROPERTIES OF G

INTRODUCTION

(Schrieber and Gareis, 2007)9

Strength High gel formation High transparent

Non-toxic

High film-forming capacity

Weakness Poor mechanical properties Poor water resistance

EXPERIMENTAL STUDY

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Glycerol (Gly)D-sorbitol powder (S)

CaCl2.2H2O

Additive Compounds

EXPERIMENTAL STUDY

1. Preparation of BC slurry

Unpurified BC

Soaked in 1 %w/v

sodium hydroxide for

24 h

Washed with DI

water until pH = 7 11

BC slurry

Crushed and

homogenized

purified BC

EXPERIMENTAL STUDY

2. Preparation of A solution

Sodium alginate of 2%

(w/w) DI water

12

EXPERIMENTAL STUDY

3. Preparation of G solutionGelatin of 15% (w/v)

DI water

13At 50±5˚C

EXPERIMENTAL STUDY

4. Preparation of BC/A/G Films

G

solution

BC

slurry

14

A

solution

At 50±5˚C

Vary1: 60/10/30

Vary2: 60/20/20

Vary3: 60/30/10Added plasticizer (Gly, S, and GS) at a ratio

of 0-3 g per 10 g gelatin solution

Homogenous mixture

EXPERIMENTAL STUDY

4. Preparation of BC/A/G Films (Cont.)

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Incubated at room

temperature to form

films

Crosslinked with 1%w/v CaCl2 solution for 1 h

Air-dried at room temperature

RESULTS AND DISCUSSION

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1. Fourier Transforms Infrared Spectroscopy

(FTIR)

A)60/10/30

B)60/20/20

C)60/30/10

D)60/20/20Gly

E)60/20/20S

F)60/20/20GS

3404

2934

1650

142410261536

3400

29251613

1424

1059

14232924

3400 10351614

3401

2928

1650

1431

10351535

3400

2927

1635

1424

1035

3393

2933

1649

143110341541

1241

1316

1316

1243

1250

1243

-NH

(1535-1541 cm-1

)

O-H-O

(1613-1650 cm-1

)

RESULTS AND DISCUSSION

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2. Water Absorption Capacity (WAC)

Condition: the BC/A/G films at ratio of 60/20/20 at room temp.

Wh = Wt. of hydrated films

Wd = Wt. of dried films

B)

C)

A)

RESULTS AND DISCUSSION

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3. Mechanical Strength

Condition: Dry

state

A)

B)

181.5

2.8

RESULTS AND DISCUSSION

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4. Mechanical Strength

Condition: Wet

state

A)

B)

CONCLUSIONS

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The composite film with BC/A/G at a ratio of 60/20/20 has superior mechanical properties for

both dry and wet states.

Glycerol is a suitable plasticizer for BC/A/G films because it improves the weakness of the

films.

The optimal ratio of glycerol to gelatin solution is 2:10 (w/w).

ACKNOWLEDGMENTS

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Chemical Engineering Research Unit for Value Adding of Bioresources

Integrated Innovation Academic Center: IIAC Chulalongkorn University Centenary

Academic Development (Project Code: CU56-AM01) (Project Code: AM667A)

Thank youfor your kind

attention