<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>Polymers derived from renewable sources which are additionally subject to degradation processes are currently an interesting alternative to conventional polymers of petrochemical origin. One of such polymers is poly(lactic acid) (PLA), which can be used in the packaging, textile and also medical industries. Its great advantage is the susceptibility to biodegradation and the nontoxicity of the degradation products. Because of high brittleness and stiffness, the modification of PLA is necessary to improve its plastic deformability, which can expand the new application possibilities. As part of the research work, the modification of PLA by plasticisation was undertaken to improve its plastic deformability properties. The low molecular mass esters from the citrate group and glycerol triacetate were used. The samples extruded from plasticised polymer were characterised using Differential Scanning Calorimetry (DSC) and Gel Permeation Chromatography/Size Exclusion Chromatography (GPC/SEC). The mechanical properties and melt flow rate after modification were determined. The aim of the research was to determine the relationship between the structure of a plasticiser and its ability to reduce the interactions in the polymer chain in order to develop an optimal polymer-plasticiser arrangement. Based on this research, there was no relationship between the efficiency of the plasticisation process and the increasing molecular mass of the plasticiser. The additional chemical (acetyl) group in the plasticiser also does not increase the efficiency of the PLA plasticisation process. In the next steps of the research, functional forms will be produced, i.e. fibers, films, and fittings from the selected polymer-plasticiser systems.</p>
</abstract>

Polymers derived from renewable sources which are additionally subject to degradation processes are currently an interesting alternative to conventional polymers of petrochemical origin. One of such polymers is poly(lactic acid) (PLA), which can be used in the packaging, textile and also medical industries. Its great advantage is the susceptibility to biodegradation and the nontoxicity of the degradation products. Because of high brittleness and stiffness, the modification of PLA is necessary to improve its plastic deformability, which can expand the new application possibilities. As part of the research work, the modification of PLA by plasticisation was undertaken to improve its plastic deformability properties. The low molecular mass esters from the citrate group and glycerol triacetate were used. The samples extruded from plasticised polymer were characterised using Differential Scanning Calorimetry (DSC) and Gel Permeation Chromatography/Size Exclusion Chromatography (GPC/SEC). The mechanical properties and melt flow rate after modification were determined. The aim of the research was to determine the relationship between the structure of a plasticiser and its ability to reduce the interactions in the polymer chain in order to develop an optimal polymer-plasticiser arrangement. Based on this research, there was no relationship between the efficiency of the plasticisation process and the increasing molecular mass of the plasticiser. The additional chemical (acetyl) group in the plasticiser also does not increase the efficiency of the PLA plasticisation process. In the next steps of the research, functional forms will be produced, i.e. fibers, films, and fittings from the selected polymer-plasticiser systems.

Influence of the Structure of Low MolecularWeight Esters on Poly(lactic acid) in the Plasticization Process - part 1

karolina.gzyra-jagiela@lit.lukasiewicz.gov.pl

Faculty of Material Technologies and Textile Design

Fibres & Textiles in Eastern Europe

This work is licensed under the Creative Commons Attribution 3.0 Public License.

Polymers derived from renewable sources which are additionally subject to degradation processes are currently an interesting alternative to conventional...

Plasticiser	Producer	M_w′, g/mol
Glycerol triacetate (TAC)	ThermoFisher Scientific, Germany	218
Triethyl citrate (TEC)	Gentham, UK	276
Acetyl triethyl citrate (Ac-TEC)	TCI, Japan	318
Tributyl citrate (TBC)	Acros, USA	360
Acetyl tributyl citrate (Ac-TBC)	Merck, Germany	402

Property	Value	Method
Specific gravity, g/cm³	1.24	ASTM D792
Relative viscosity	3.1	CD Internal Viscotek Method
Melt index (210°C), g/10 min	15–30	ASTM D1238
Glass transition temperature, °C	55–60	ASTM D3417
Crystalline melt temperature, °C	160–170	ASTM D3418

Sample	Thermal analysis
Sample	T_g′, °C	ΔC_p′, J/gK	T_cc′, °C	ΔH_cc′, J/g	T_m′, °C	ΔH_m′, J/g
base PLA	60.0	0.50	123.9	42.1	165.9	42.2
Plasticiser	Plasticised PLA
TAC	38.8	0.51	100.8	35.2	150.0161.9	35.3
TEC	41.7	0.52	104.2	35.1	153.0164.4	35.3
Ac-TEC	37.5	0.50	101.6	34.3	149.8162.1	34.4
TBC	37.8	0.49	93.0	34.6	148.9163.7	34.8
Ac-TBC	40.1	0.52	96.0	35.0	151.0164.1	35.0

Influence of the Structure of Low MolecularWeight Esters on Poly(lactic acid) in the Plasticization Process - part 1

Article Category: Research Article

Published Online: Sep 28, 2022

Page range: 93 - 101

DOI: https://doi.org/10.2478/ftee-2022-0027

Keywords
polylactic acid, plasticisation, GPC/SEC, citrate, glycerol triacetate

© 2022 Karolina Gzyra-Jagieła, et al, published by Sciendo

This work is licensed under the Creative Commons Attribution 3.0 Public License.

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Fig. 6

Fig. 7

Fig. 8

Fig. 9

Fig. 10

Fig. 11

Fig. 12

Substances used in the PLA plasticisation process

Properties of 6201D PLA according to manufacturer's data

Thermal parameters obtained during the second heating

Influence of the Structure of Low MolecularWeight Esters on Poly(lactic acid) in the Plasticization Process - part 1

Article Category: Research Article

Published Online: Sep 28, 2022

Page range: 93 - 101

DOI: https://doi.org/10.2478/ftee-2022-0027

Keywordspolylactic acid, plasticisation, GPC/SEC, citrate, glycerol triacetate

© 2022 Karolina Gzyra-Jagieła, et al, published by Sciendo

This work is licensed under the Creative Commons Attribution 3.0 Public License.

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Fig. 6

Fig. 7

Fig. 8

Fig. 9

Fig. 10

Fig. 11

Fig. 12

Substances used in the PLA plasticisation process

Properties of 6201D PLA according to manufacturer's data

Thermal parameters obtained during the second heating

Keywords
polylactic acid, plasticisation, GPC/SEC, citrate, glycerol triacetate