Project Code:

PN-II-RU-PD-2011-3-0057

 Project title:

Fast thermal analysis evaluation of biopolymer biodegradability

  Project Summary:

The project aims at the identification of correlation factors between the some physical parameters and the potential of biodegradation of new biopolymers (cellulose obtained by microbial biosynthesis, low density polyethylene in which natural antioxidants have been incorporated) by means of thermal methods complemented with structural and morphological analysis. The experimental study will be conducted using TGA coupled with FTIR spectroscopy, DSC and dilatometry. The objectives are: the comparative study of methods for determining physical properties of biopolymers; characterization of new biopolymers using thermal methods of analysis; bridging results of thermal analysis with those provided by XRD, FTIR and SEM; identifying of the possible correlation factors between data obtained from thermal analysis methods and microbiological studies in order to assess the microbiological potential for biodegradation. Starting from available experimental measurements a number of physical properties of biopolymers will be evaluated using a software package suitable for thermal analysis. The obtained results will form the basis of a model/method of assessment and forecasting of biodegradation of biopolymer materials, as an alternative to the standard methods of biodegradability evaluation which are expensive and long lasting. These results would also contribute to the theoretical design of new biopolymers with a higher biodegradability potential.

Keywords:

thermal analysis, kinetic modeling, biodegradability, biopolymers, low density polyethylene (LDPE).

 Project duration:

05.10.2011 - 04.10.2013

 


Budget (lei):

Budget chapter (expenses)

2011 (lei)

2012 (lei)

2013 (lei)

 

Total (lei)

Salaries

27230

71450

43470

142240

Inventory

18670

75480.57

9980.08

104130.65

Mobility

0

9029.43

12359.92

21389.35

Overhead

5445

16322

10473

32240

Total

51435

172282

76283

300000

 Project Leader:

Dr. Adina Magdalena Musuc, Scientific Researcher III

"Ilie Murgulescu" Institute of Physical Chemistry, 202 Splaiul Independentei St., 060021, Bucharest, Romania

E-mail: musucadina@yahoo.com; amusuc@icf.ro

 Postdoctoral advisor:

Dr. Vlad Tudor Popa, Director

"Ilie Murgulescu" Institute of Physical Chemistry, 202 Splaiul Independentei St., 060021, Bucharest, Romania

E-mail: vtpopa@icf.ro ; vtpopa@gmail.com

 National Collaborations:

Chem. Luiza Jecu, Ph.D., Senior researcher I, Biotechnology Department Manager

INCDCP-ICECHIM, 202 Spl. Independentei, 060021, Bucharest, Romania

E-mail: jecu.luiza@icechim.ro

 

Biochem. Mihaela Badea Doni, Ph.D., Senior researcher II, Department Manager Deputy

INCDCP-ICECHIM, 202 Spl. Independentei, 060021, Bucharest, Romania

E-mail: mihaela.badea@icechim.ro 

 

Objectives:

The main objective of the present project is the use of thermal analysis methods in addition to other methods of analysis (XRD, FTIR, SEM) for characterization of unmodified/modified polymers before and after microbial attack. The aim is to establish the correlation factors between thermophysical and structural properties and the microbiological methods in order to determine the potential of biodegradation of biopolymers.

Specific objectives:

  1. The comparative study of methods for determining physical properties of biopolymers.

Methodology: Various experimental methods, in order to study the properties of biopolymers will be examined. In literature there are a number of methods used to assess the characteristic parameters of biodegradation processes. Thus, the degree of crystallization can be estimated using X-ray diffraction. Thermal properties such as phase transitions, crystallization or melting are estimated using DSC and TG analysis. The dilatometric analysis follows physical transformations occurring in thermal expansion of materials. Analysis of transformation in IR spectrometry is used to observe structural changes of biopolymers. An original contribution will be the corroboration of these methods to obtain results in appropriate conditions.

  1. Characterization of biopolymers: bio(cellulose) and LDPE before and after microbial attack using thermal methods of analysis.

Methodology: The thermal transformations take place in different conditions: non-isothermal or isothermal regime. Next stage of this process is the total breakdown in the final product of combustion. It will be followed the thermal behavior of studied biopolymers obtained before and after microbial attack in conditions of programmed temperature and isothermal mode which give an adequate description of thermal behavior of biopolymers. Use of patterns and plausible mechanisms are also integrated as a significant original contribution in the current efforts of scientific community for obtaining new biopolymers as a high degree of biodegradability.

  1. The combined use of thermal methods of biopolymers with XRD, FTIR and SEM methods, achieved by comparing the measured and the calculated values of thermal methods to those obtained from other techniques.

Methodology: Calculations will be made with existing software of thermal analysis programs as well as other computer programs, which will be purchased during the project. The validation at this stage of research should be done with further investigation using available information obtained by scientific exchanges by nationally and internationally cooperation.

  1. Identifying the possible correlation factors between thermal analysis and the other studies in order to assess the microbiological potential for biodegradation of biopolymers.

Methodology: This will be achieved through experimental and modeling of obtained data. The results will form the basis of a model/method of assessment and forecasting of biodegradation of biopolymer materials. Generally, the standard method of evaluation of this process is expensive and long lasting. The results will form the theoretical design of new biopolymers materials, subject to biodegradation processes.

 

Results: October 2011 – December 2012

International Conferences:

 

A M Musuc, Mihaela Badea-Doni, Iuliana Raut, Victor Fruth, Vlad Tudor Popa, Effect of the rosemary extract on polyethylene structure and biodegradability, AICAT 2012, XXXIV National Congress on Calorimetry, Thermal Analysis and Applied Thermodynamics, June 5-8, 2012, Rome, Italy (poster)

Abstract:

The aim of this work was to study the effect of the rosemary (Rosmarinus officinalis) extract used as antioxidant in polyethylene foils production. It is well known that the polyethylene used for food packaging contains synthetic antioxidants which are often able to migrate and to contaminate the food. In order to avoid this contamination, natural extracts with antioxidant properties may be an interesting alternative for the polyethylene fabrication. Influence of the rosemary extract present in different concentrations (0.25 %, 0.5 % and 1 %) on the polyethylene properties and on its biodegradability was studied. The biodegradability studies were carried on by incubating the modified polyethylene with different microbial strains as: Penicillum sp., Aspergillus niger, Bacillus licheniformis, Candida lipolytica. The incubation period was of 30 days, in highly nutritive liquid medium, under stirring, at 37°C. The structure of the samples of polyethylene modified with rosemary extracts, before and after the microbial attack, was investigated using the following methods: optical microscopy, XRD, FTIR and DSC.

 

A. M. Musuc, M. Badea Doni, L. Jecu, A. Rusu and V.T. Popa, Fast evaluation of polymer composites biodegradability, Thermal analysis and calorimetry techniques, Workshop, 26-27 September 2012, Bucharest, Romania (oral presentation)

 

A. M. Musuc, M. Badea Doni, L. Jecu, A. Rusu and V.T. Popa, Thermo-analytical investigation of structure and biodegradability of low density polyethylene,  PRIORITĂŢILE CHIMIEI PENTRU O DEZVOLTARE DURABILĂ - PRIOCHEM - ed. aVIIIa, 25 - 26 October 2012, Bucharest, Romania (oral presentation)

Abstract:

The increasing use of synthetic films leads to a series of ecological problems due to their non-biodegradability [1-4]. Current food packaging must be resistant to immediate microbial attack in order to prevent food contamination due to damaged packaging before expiration the product warranty, and on the other hand must be biodegradable in order to meet the environmental protection [5-7]. Polyethylene is one of the synthetic polymers widely used as packaging material. In natural form, it is not biodegradable. To make polyethylene biodegradable requires modifying its crystalline degree, molecular weight and mechanical properties that are responsible for its resistance towards degradation [8]. The biodegradability studies were carried out by incubating the low density polyethylene films (LDPE) modified with natural antioxidants with Aspergillus sp. in liquid media for 50 days. The structure of the samples before and after microbial attack was investigated using the following methods: optical microscopy, X-ray diffractions (XRD), Fourier Transform Infrared Spectroscopy (FT-IR) and microcalorimetry (microDSC).

 

Publication:

A. M. Musuc, M Badea-Doni, L. Jecu, A. Rusu and V.T. Popa, FTIR, XRD, and DSC analysis of the rosemary extract effect on polyethylene structure and biodegradability,  J Therm Anal Calorim 114 (1), 169-177, doi: 10.1007/s10973-012-2909-y, I.F. – 1.982 (2013)

Abstract:  Differential scanning calorimetry (DSC) technique enabled the study of the effect of the rosemary (Rosmarinus officinalis) extract on polyethylene foils structure and biodegradability. The polyethylene used for food packaging contains synthetic antioxidants which are often able to migrate and to contaminate the food. Natural extracts with antioxidant properties may be an interesting alternative for the polyethylene fabrication. The influence of the rosemary present in different concentrations in nonirradiated and irradiated polyethylene samples was studied. The biodegradability studies were carried out by incubating the modified polyethylene with the yeast Candida lipolytica. The changes of physical properties and morphological aspects before and after fungal attack were studied by Fourier Transform Infrared Spectroscopy, X-ray diffraction, and DSC. With some exceptions due to the nonuniform character of the investigated samples, the melting peak temperature and crystallization degree were found to decrease with increasing of rosemary content and irradiation. Synergic effects of rosemary and irradiation on the film biodegradability were directly confirmed by optical microscopy.

Keywords: Biodegradability, Crystallization, Differential scanning calorimetry, Low-density polyethylene, Polymer composite.

 

Summer School

June 10 – 15, 2012Summer School of Calorimetry, Lyon, France

Main activities for 2013

Calculation of physical and chemical parameters of biodegradation processes of studied biopolymers, obtained from the use of all methods of analysis;

Predicting and identifying the correlation factors on the basis of the obtained parameters;

Validation of the most plausible models based on various statistical criteria recommended in the literature;

Dissemination of the results at international conferences and publishing.

International Conferences:

 

Adina Magdalena MUSUC, Mihaela BADEA – DONI, Luiza JECU, Vlad Tudor POPA, MicroDSC analysis of low density polyethylene biodegradability, Lucrarile celui de al 22-lea Simpozion anual de comunicari stiintifice, Academia Romana, sectia de Stiinte Chimice, Comisia de Analiza Termica si Calorimetrie, 15 februarie 2013, Bucuresti (oral presentation).

 

Adina Magdalena MUSUC, Silviu PREDA, Vlad Tudor POPA, Luiza JECU, Mihaela BADEA – DONI, Iulia RAUT, Mariana CALIN, Spectral characterization and thermal studies of poly(hydroxybutyrate)/poly(vinyl alcohol) blend biodegradation,8-th International Conference on Materials Science & Engineering – BRAMAT 2013, Brasov – ROMANIA, 28 February – 2 March 2013 (poster).

Abstract:

Traditional plastic materials exhibit very long time of environmental decomposition, which represents a serious problem with long life of plastic waste. One possibility of solution this problem is development of packages from biodegradable polymer materials. The blending of these materials is a method of reducing the overall cost of the material and offers a solution of modifying both properties and degradation rates [1, 2]. Poly(hydroxybutyrate) (PHB) is a well-known anti-microbial and biodegradable polymer [3]. One way to improve the physical properties of PHB is to mix it with another polymer, such as poly(vinyl alcohol) (PVA). PHB – PVA blends are of great interest as biodegradable films and coatings materials useful in the packaging industry, for agricultural application and in biomedicine. The aim of present work is to study the behavior of PHB – PVA blends exposed to different microbial strains (bacteria, yeast, fungi) contact. The effects of fungal strain on polymer features were analyzed using Fourier transform infrared spectroscopy FTIR, x-ray diffraction (XRD) and differential scanning calorimetry (DSC) methods.

 

International Conferences (June – September 2013):

 

Adina Magdalena Musuc, Mihaela Badea-Doni, Luiza Jecu and Vlad Tudor Popa, Biodegradation of low density polyethylene by Aspergillus Niger via microDSC analysis, International Conference of Physical Chemistry - RomPhysChem 15, 11-13 September 2013, Bucharest, Romania (poster).

 

Adina Magdalena MUSUC, Mihaela BADEA-DONI, Luiza JECU, Melania Liliana ARSENE and Vlad Tudor POPA, Influence of incubation time upon microbial degradation  of POLY (HYDROXYBUTYRATE) / POLY(VINYL ALCOHOL) BLENDS evaluated by thermal analysis, 18th Romanian International Conference on Chemistry and Chemical Engineering, RICCCE18, 4-7 september 2013, Sinaia, Romania – oral presentation.

 

Adina Magdalena Musuc, Mihaela Badea –Doni, Luiza Jecu, Vlad Tudor Popa, Biodegradation of polyethylene evaluated by microcalorimetry, 2nd Central and Eastern European Conference on Thermal Analysis and Calorimetry CEEC-TAC2, 27-30 August 2013, Vilnius, Lithuania (poster).

 

Adina Magdalena Musuc, Luiza Jecu, Mihaela Badea-Doni and Vlad Tudor Popa, THE USE OF DSC TECHNIQUE IN EVALUATION OF POLY(VINYL ALCOHOL) / BACTERIAL CELLULOSE COMPOSITES BIODEGRADABILITY, XIV International Conference on Thermal Analysis and Calorimetry in Russia (RTAC-2013), 23 – 28 September, 2013, Saint-Petersburg, Russia (oral communication).

 

Summer School (June – September 2013):

The Combustion Institute Summer School 2013, 19 - 23 august 2013 Lund University, Suedia

Short Summer School on TA&C, SSS on TA&C, 27th of August 2013, Vilnius, Lithuania

 

Two manuscripts in progress. Their provisionally titles are:

 

Kinetic analysis of melting and crystallization processes of microbial degradation of polyethylene via microcalorimetry

The influence of incubation time upon microbial degradation of polyhydroxybutyrate – polyvinyl alcohol blends

 

 

Overall remarks:

 

At the end of this research the proposed objectives of the project were fully achieved.

 

The obtained results will form the basis of a model/method of assessment and forecasting of biodegradation of biopolymer materials which may be adapted for application in a variety of industries: food industry, pharmaceuticals and medicine.

 

The new bioassay techniques developed in this project could address important issues in healthcare, food science, pharmaceuticals and environmental science, with significant economic impact.