8 Oleochemistry Products
245
viz. the hydroxyl group, the double bond and the glyceride ester linkage. CO fatty acid
(COFA) with a pendant hydroxyl group on each ricinoleate chain has been considered
as a source of many oleochemicals after appropriate modifications. Plastic products
of CO are not only soft, flexible, odourless but also completely biodegradable, which
is an added advantage [236]. Several families of CO-based polymers are synthesized
and used to improve thermal stabilities, flame retardancy and mechanical properties.
The CO or brominated CO used as a reinforcing agent is added to epoxy resins and
good toughness and flame retardancy of cured epoxy resins are obtained. Synthesis
and properties of CO-based polyurethane hybrid materials have been reported [157].
Cured epoxy resin modified by brominated CO possesses good flame retardation,
toughness, moderate smoke suppression and some degree of resistance to heat [235].
Mechanically strong cellulose-graft-soybean oil copolymers, which combined
two natural biomasses into one was reported by Wu et al. [234]. The soybean
oil based monomers with secondary amide groups (SOM1) and tertiary amide
groups (SOM2) were prepared and copolymerized. Cellulose-g-P(SOM1-co-SOM2)
copolymers with 0.5 wt% cellulose were prepared via atom radical transfer polymerization. Cellulose-g-P(SOM1-co-SOM2) copolymers were successfully prepared
with mechanical properties superior to the linear P(SOM1-co-SOM2) copolymers
[234].
Bionanocomposite films prepared with melt compounding and film blowing were
evaluated for packaging applications. The nanocomposite masterbatch with PLA,
chitin nanocrystals (ChNCs) and glycerol triacetate plasticizer (GTA) was melt compounded and then diluted to 1 wt% ChNCs with PLA and polybutylene adipate-coterephthalate (PBAT) prior to film blowing. The morphological, mechanical, optical,
thermal and barrier properties of the blown nanocomposite films were comparable
to those of the reference material without ChNCs. Tear strength, puncture strength
improved Tg increased crystallinity enhanced by the addition of the ChNCs. ChNCs
had lower fungal activity and lower electrostatic attraction between the film surfaces;
leading to the easy opening of the plastic bags [83].
8.5.2 Role of Plasticisers
The International Union of Pure and Applied Chemistry (IUPAC) council, in 1951,
defined with the term plasticiser ‘a substance or material incorporated in a material, to increase its flexibility, workability, or distensibility’ [230]. Therefore, the
plasticizers mainly act by improving the flexibility and processability of plastic by
reducing its glass transition temperature (T g ) [50, 127, 202, 232]. The presence of
the plasticizer allows us to ease the processability of the material in different tools
(such as upon moulding, extrusion, etc.), and to optimize the applied experimental
conditions. Moreover, the plasticizers enhance some physical properties of the materials, like promoting the reduction of hardness and elastic modulus, and the increase
in fracture resistance.
245
viz. the hydroxyl group, the double bond and the glyceride ester linkage. CO fatty acid
(COFA) with a pendant hydroxyl group on each ricinoleate chain has been considered
as a source of many oleochemicals after appropriate modifications. Plastic products
of CO are not only soft, flexible, odourless but also completely biodegradable, which
is an added advantage [236]. Several families of CO-based polymers are synthesized
and used to improve thermal stabilities, flame retardancy and mechanical properties.
The CO or brominated CO used as a reinforcing agent is added to epoxy resins and
good toughness and flame retardancy of cured epoxy resins are obtained. Synthesis
and properties of CO-based polyurethane hybrid materials have been reported [157].
Cured epoxy resin modified by brominated CO possesses good flame retardation,
toughness, moderate smoke suppression and some degree of resistance to heat [235].
Mechanically strong cellulose-graft-soybean oil copolymers, which combined
two natural biomasses into one was reported by Wu et al. [234]. The soybean
oil based monomers with secondary amide groups (SOM1) and tertiary amide
groups (SOM2) were prepared and copolymerized. Cellulose-g-P(SOM1-co-SOM2)
copolymers with 0.5 wt% cellulose were prepared via atom radical transfer polymerization. Cellulose-g-P(SOM1-co-SOM2) copolymers were successfully prepared
with mechanical properties superior to the linear P(SOM1-co-SOM2) copolymers
[234].
Bionanocomposite films prepared with melt compounding and film blowing were
evaluated for packaging applications. The nanocomposite masterbatch with PLA,
chitin nanocrystals (ChNCs) and glycerol triacetate plasticizer (GTA) was melt compounded and then diluted to 1 wt% ChNCs with PLA and polybutylene adipate-coterephthalate (PBAT) prior to film blowing. The morphological, mechanical, optical,
thermal and barrier properties of the blown nanocomposite films were comparable
to those of the reference material without ChNCs. Tear strength, puncture strength
improved Tg increased crystallinity enhanced by the addition of the ChNCs. ChNCs
had lower fungal activity and lower electrostatic attraction between the film surfaces;
leading to the easy opening of the plastic bags [83].
8.5.2 Role of Plasticisers
The International Union of Pure and Applied Chemistry (IUPAC) council, in 1951,
defined with the term plasticiser ‘a substance or material incorporated in a material, to increase its flexibility, workability, or distensibility’ [230]. Therefore, the
plasticizers mainly act by improving the flexibility and processability of plastic by
reducing its glass transition temperature (T g ) [50, 127, 202, 232]. The presence of
the plasticizer allows us to ease the processability of the material in different tools
(such as upon moulding, extrusion, etc.), and to optimize the applied experimental
conditions. Moreover, the plasticizers enhance some physical properties of the materials, like promoting the reduction of hardness and elastic modulus, and the increase
in fracture resistance.