Roderik Plavec - Academia.edu (original) (raw)

Papers by Roderik Plavec

Research paper thumbnail of Evaluation of the Properties of PHB Composite Filled with Kaolin Particles for 3D Printing Applications Using the Design of Experiment

International Journal of Molecular Sciences

In the presented work, poly(3-hydroxybutyrate)-PHB-based composites for 3D printing as bio-source... more In the presented work, poly(3-hydroxybutyrate)-PHB-based composites for 3D printing as bio-sourced and biodegradable alternatives to synthetic plastics are characterized. The PHB matrix was modified by polylactide (PLA) and plasticized by tributyl citrate. Kaolin particles were used as a filler. The mathematical method “Design of Experiment” (DoE) was used to create a matrix of samples for further evaluation. Firstly, the optimal printing temperature of the first and upper layers was determined. Secondly, the 3D printed samples were tested with regards to the warping during the 3D printing. Testing specimens were prepared using the determined optimal printing conditions to measure the tensile properties, impact strength, and heat deflection temperature (HDT) of the samples. The results describe the effect of adding individual components (PHB, PLA, plasticizer, and filler) in the prepared composite sample on the resulting material properties. Two composite samples were prepared based...

Research paper thumbnail of PLA/PHB-Based Materials Fully Biodegradable under Both Industrial and Home-Composting Conditions

Polymers

In order to make bioplastics accessible for a wider spectrum of applications, ready-to-use plasti... more In order to make bioplastics accessible for a wider spectrum of applications, ready-to-use plastic material formulations should be available with tailored properties. Ideally, these kinds of materials should also be “home-compostable” to simplify their organic recycling. Therefore, materials based on PLA (polylactid acid) and PHB (polyhydroxybutyrate) blends are presented which contain suitable additives, and some of them contain also thermoplastic starch as a filler, which decreases the price of the final compound. They are intended for various applications, as documented by products made out of them. The produced materials are fully biodegradable under industrial composting conditions. Surprisingly, some of the materials, even those which contain more PLA than PHB, are also fully biodegradable under home-composting conditions within a period of about six months. Experiments made under laboratory conditions were supported with data obtained from a kitchen waste pilot composter and ...

Research paper thumbnail of Mechanical, Thermal, Electrical Characteristics and EMI Absorption Shielding Effectiveness of Rubber Composites Based on Ferrite and Carbon Fillers

Polymers

In this work, rubber composites were fabricated by incorporation of manganese-zinc ferrite alone ... more In this work, rubber composites were fabricated by incorporation of manganese-zinc ferrite alone and in combination with carbon-based fillers into acrylonitrile-butadiene rubber. Electromagnetic parameters and electromagnetic interference (EMI) absorption shielding effectiveness of composite materials were examined in the frequency range 1 MHz–3 GHz. The influence of ferrite and fillers combination on thermal characteristics and mechanical properties of composites was investigated as well. The results revealed that ferrite imparts absorption shielding efficiency to the composites in tested frequency range. The absorption shielding effectiveness and absorption maxima of ferrite filled composites shifted to lower frequencies with increasing content of magnetic filler. The combination of carbon black and ferrite also resulted in the fabrication of efficient EMI shields. However, the EMI absorption shielding effectiveness was lower, which can be ascribed to higher electrical conductivit...

Research paper thumbnail of Influence of Multiple Thermomechanical Processing of 3D Filaments Based on Polylactic Acid and Polyhydroxybutyrate on Their Rheological and Utility Properties

Polymers

This study focused on material recycling of a biodegradable blend based on PLA and PHB for multip... more This study focused on material recycling of a biodegradable blend based on PLA and PHB for multiple applications of biodegradable polymeric material under real conditions. In this study, we investigated the effect of multiple processing of a biodegradable polymer blend under the trade name NONOILEN®, which was processed under laboratory as well as industrial conditions. In this article, we report on testing the effect of blending and multiple processing on thermomechanical stability, molecular characteristics, as well as thermophysical and mechanical properties of experimental- and industrial-type tested material suitable for FDM 3D technology. The results showed that the studied material degraded during blending and subsequently during multiple processing. Even after partial degradation, which was demonstrated by a decrease in average molecular weight and a decrease in complex viscosity in the process of multiple reprocessing, there was no significant change in the material’s therm...

Research paper thumbnail of In Vitro Characterization of Poly(Lactic Acid)/ Poly(Hydroxybutyrate)/ Thermoplastic Starch Blends for Tissue Engineering Application

Cell Transplantation, 2021

Complex in vitro characterization of a blended material based on Poly(Lactic Acid), Poly(Hydroxyb... more Complex in vitro characterization of a blended material based on Poly(Lactic Acid), Poly(Hydroxybutyrate), and Thermoplastic Starch (PLA/PHB/TPS) was performed in order to evaluate its potential for application in the field of tissue engineering. We focused on the biological behavior of the material as well as its mechanical and morphological properties. We also focused on the potential of the blend to be processed by the 3D printer which would allow the fabrication of the custom-made scaffold. Several blends recipes were prepared and characterized. This material was then studied in the context of scaffold fabrication. Scaffold porosity, wettability, and cell-scaffold interaction were evaluated as well. MTT test and the direct contact cytotoxicity test were applied in order to evaluate the toxic potential of the blended material. Biocompatibility studies were performed on the human chondrocytes. According to our results, we assume that material had no toxic effect on the cell cultur...

Research paper thumbnail of Printability, Mechanical and Thermal Properties of Poly(3-Hydroxybutyrate)-Poly(Lactic Acid)-Plasticizer Blends for Three-Dimensional (3D) Printing

Materials, 2020

This paper investigates the effect of plasticizer structure on especially the printability and me... more This paper investigates the effect of plasticizer structure on especially the printability and mechanical and thermal properties of poly(3-hydroxybutyrate)-poly(lactic acid)-plasticizer biodegradable blends. Three plasticizers, acetyl tris(2-ethylhexyl) citrate, tris(2-ethylhexyl) citrate, and poly(ethylene glycol)bis(2-ethylhexanoate), were first checked whether they were miscible with poly(3-hydroxybutyrate)-poly(lactic acid) (PHB-PLA) blends using a kneading machine. PHB-PLA-plasticizer blends of 60-25-15 (wt.%) were then prepared using a corotating meshing twin-screw extruder, and a single screw extruder was used for filament preparation for further three-dimensional (3D) fused deposition modeling (FDM) printing. These innovative eco-friendly PHB-PLA-plasticizer blends were created with a majority of PHB, and therefore, poor mechanical properties and thermal properties of neat PHB-PLA blends were improved by adding appropriate plasticizer. The plasticizer also influences the pri...

Research paper thumbnail of Erratum: Influence of Composition and Plasma Power on Properties of Film from Biodegradable Polymer Blends. Polymers 2020, 12, 1592

Polymers, 2020

The authors wish to make a change to the published paper [...]

Research paper thumbnail of Influence of Composition and Plasma Power on Properties of Film from Biodegradable Polymer Blends

Polymers, 2020

The work is focused on the study of surface plasma treatment (DCSBD) of films from biodegradable ... more The work is focused on the study of surface plasma treatment (DCSBD) of films from biodegradable polymers from renewable sources based on polylactic acid (PLA) and polyhydroxybutyrate (PHB). A 4-factor design of experiment was used where the selected variable parameters were the plasma device power, the time of plasma treatment, the ratio of PHB in the polymer blend with PLA, and the content of acetyl tributyl citrate (ATBC) plasticizer in the PLA + PHB blend. The surface total energy and the polar component were evaluated immediately after surface plasma treatment and after 5 h of sitting. Topography of foil surfaces was also studied by AFM. In terms of plasma power and activation time, the greatest increase in surface energy values was observed with a short plasma time of 2 s and a high power of 400 W. Increasing the content of ATBC in interaction with the high concentration of PHB in the blend results in a reduction in the difference of both the polar component and the total free...

Research paper thumbnail of Low frequency electromagnetic shielding efficiency of composites based on ethylene propylene diene monomer and multi‐walled carbon nanotubes

Polymers for Advanced Technologies, 2020

Ethylene propylene diene monomer rubber was filled with multi‐walled carbon nanotubes to prepare ... more Ethylene propylene diene monomer rubber was filled with multi‐walled carbon nanotubes to prepare composite materials with the effect of electromagnetic radiation (EMR) shielding. Sulfur‐based curing system as well as peroxide curing system were used for vulcanization of rubber compounds. The main goal of the work was the investigation of curing system composition and filler content on curing process, physical‐mechanical properties, cross‐link density, and shielding efficiency of the prepared composites. The results showed that curing characteristics and cross‐link density of composites were dependent on both, amount of carbon nanotubes and curing system composition. The incorporation of filler resulted in the enhancement of physical‐mechanical properties of composites. Higher values of tensile strength were found to have composites cured with organic peroxide in combination with co‐agent. The achieved results also demonstrated that carbon nanotubes filled rubber composites are suita...

Research paper thumbnail of Mechanical testing of hydroxyapatite filaments for tissue scaffolds preparation by fused deposition of ceramics

Journal of the European Ceramic Society, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Research paper thumbnail of The influence of additives on crystallization of blends based on polylactid acid

IOP Conference Series: Materials Science and Engineering, 2017

The sustainable development consists of the effort of replacing commonly used polymer materials f... more The sustainable development consists of the effort of replacing commonly used polymer materials for the biodegradable ones. They do not have sufficient physical and mechanical properties, therefore they have to be modified by producing various ratio mixtures or with the additives. Improving their processability and properties is an important challenge to be afforded before using these materials on the market. One way to improve the properties of these materials is to prepare their blends [1]. The most common way of the preparation of packaging materials is the injection moulding, where the crystallization of material is very important. That is the reason the crystallization has become one of the most studied characteristics of biodegradable blends based on PLA / PHB. The work is a contribution to works that deal with the description of the structure of PLA / PHB blends, which have been modified by the addition of various types of additives, mainly nucleating agents and plasticizers [2]. The films of these blends keep approximately unchanged mechanical properties after two weeks of storage. The presence of plasticizer (ATBC) and nucleating agent (BN) has no significant impact on the processing stability of PLA/PHB blends. The results show that the combination of the plasticizer and nucleating agent greatly affects the process of crystallization of PLA/PHB blends as well as the ratio of polymers and the heat treatment process.

Research paper thumbnail of Effect of PHB on the properties of biodegradable PLA blends

Chemical Papers, 2016

Blends of biodegradable polymers polylactic acid/thermoplastic starch/polyhydroxybutyrate (PLA/TP... more Blends of biodegradable polymers polylactic acid/thermoplastic starch/polyhydroxybutyrate (PLA/TPS/PHB) were prepared using a twin-screw extruder. The TPS content was constant (50 %) and the PHB content in the blends was gradually changed from 0 mass % to 20 mass %. TPS was prepared by melting, where a mixture of native starch, water and glycerol was fed into the twin-screw extruder. Average temperature of extrusion was 180 °C and the concentration of glycerol was 40 mass %. Influence of the PHB concentration in the blend and that of the processing technology on the mechanical and rheological properties of the PLA/PHB composition containing TPS were studied. Mechanical properties were measured 24 h after the film and monofilament preparation and also after the specific storage time to study the effect of storage on the properties. The results indicate that differences in morphology strongly influence the mechanical properties of the studied materials with identical material composit...

Research paper thumbnail of Biologically Degradable Polymeric Composition with High Deformability

Research paper thumbnail of Oscillation rheometry – method for processing stability testing of high sensitive polymers

AIP Conference Proceedings, 2015

This work introduces the oscillation rheometry as a method for determination of processing stabil... more This work introduces the oscillation rheometry as a method for determination of processing stability of polymers, which are high sensitive to degradation during melt processing. The oscillation rheometry was found as a simple and rapid method which could indicate the first stages of degradation process. Changes in relative complex viscosity were taken as indicator of processing stability. It was shown that changes in relative complex viscosity reflect changes in molecular weight of degraded polymer very well.

Research paper thumbnail of Recycling possibilities of bioplastics based on PLA/PHB blends

Polymer Testing, 2020

The study is focused on modelling the evaluation of recyclability of the biodegradable blend usin... more The study is focused on modelling the evaluation of recyclability of the biodegradable blend using multiple extrusion of selected composition of PLA/PHB blend which had been more deeply studied before. It was shown that the multiple extrusion reduces viscosity of the tested blend due to multiple thermomechanical stresses and the material was partially degraded. Partial degradation was demonstrated by measuring of molecular characteristics. The degree of degradation of the tested material was determined with relatively high accuracy after creating a colour space/viscosity. Multiple processing and subsequent degradation of the tested material did not negatively affect thermal properties, as well as strength characteristics of the blend. It was concluded that the biodegradable polymer blend of the PLA/PHB type is suitable for multiple processing and material recycling can be applied for this type of bioplastics.

Research paper thumbnail of Evaluation of the Properties of PHB Composite Filled with Kaolin Particles for 3D Printing Applications Using the Design of Experiment

International Journal of Molecular Sciences

In the presented work, poly(3-hydroxybutyrate)-PHB-based composites for 3D printing as bio-source... more In the presented work, poly(3-hydroxybutyrate)-PHB-based composites for 3D printing as bio-sourced and biodegradable alternatives to synthetic plastics are characterized. The PHB matrix was modified by polylactide (PLA) and plasticized by tributyl citrate. Kaolin particles were used as a filler. The mathematical method “Design of Experiment” (DoE) was used to create a matrix of samples for further evaluation. Firstly, the optimal printing temperature of the first and upper layers was determined. Secondly, the 3D printed samples were tested with regards to the warping during the 3D printing. Testing specimens were prepared using the determined optimal printing conditions to measure the tensile properties, impact strength, and heat deflection temperature (HDT) of the samples. The results describe the effect of adding individual components (PHB, PLA, plasticizer, and filler) in the prepared composite sample on the resulting material properties. Two composite samples were prepared based...

Research paper thumbnail of PLA/PHB-Based Materials Fully Biodegradable under Both Industrial and Home-Composting Conditions

Polymers

In order to make bioplastics accessible for a wider spectrum of applications, ready-to-use plasti... more In order to make bioplastics accessible for a wider spectrum of applications, ready-to-use plastic material formulations should be available with tailored properties. Ideally, these kinds of materials should also be “home-compostable” to simplify their organic recycling. Therefore, materials based on PLA (polylactid acid) and PHB (polyhydroxybutyrate) blends are presented which contain suitable additives, and some of them contain also thermoplastic starch as a filler, which decreases the price of the final compound. They are intended for various applications, as documented by products made out of them. The produced materials are fully biodegradable under industrial composting conditions. Surprisingly, some of the materials, even those which contain more PLA than PHB, are also fully biodegradable under home-composting conditions within a period of about six months. Experiments made under laboratory conditions were supported with data obtained from a kitchen waste pilot composter and ...

Research paper thumbnail of Mechanical, Thermal, Electrical Characteristics and EMI Absorption Shielding Effectiveness of Rubber Composites Based on Ferrite and Carbon Fillers

Polymers

In this work, rubber composites were fabricated by incorporation of manganese-zinc ferrite alone ... more In this work, rubber composites were fabricated by incorporation of manganese-zinc ferrite alone and in combination with carbon-based fillers into acrylonitrile-butadiene rubber. Electromagnetic parameters and electromagnetic interference (EMI) absorption shielding effectiveness of composite materials were examined in the frequency range 1 MHz–3 GHz. The influence of ferrite and fillers combination on thermal characteristics and mechanical properties of composites was investigated as well. The results revealed that ferrite imparts absorption shielding efficiency to the composites in tested frequency range. The absorption shielding effectiveness and absorption maxima of ferrite filled composites shifted to lower frequencies with increasing content of magnetic filler. The combination of carbon black and ferrite also resulted in the fabrication of efficient EMI shields. However, the EMI absorption shielding effectiveness was lower, which can be ascribed to higher electrical conductivit...

Research paper thumbnail of Influence of Multiple Thermomechanical Processing of 3D Filaments Based on Polylactic Acid and Polyhydroxybutyrate on Their Rheological and Utility Properties

Polymers

This study focused on material recycling of a biodegradable blend based on PLA and PHB for multip... more This study focused on material recycling of a biodegradable blend based on PLA and PHB for multiple applications of biodegradable polymeric material under real conditions. In this study, we investigated the effect of multiple processing of a biodegradable polymer blend under the trade name NONOILEN®, which was processed under laboratory as well as industrial conditions. In this article, we report on testing the effect of blending and multiple processing on thermomechanical stability, molecular characteristics, as well as thermophysical and mechanical properties of experimental- and industrial-type tested material suitable for FDM 3D technology. The results showed that the studied material degraded during blending and subsequently during multiple processing. Even after partial degradation, which was demonstrated by a decrease in average molecular weight and a decrease in complex viscosity in the process of multiple reprocessing, there was no significant change in the material’s therm...

Research paper thumbnail of In Vitro Characterization of Poly(Lactic Acid)/ Poly(Hydroxybutyrate)/ Thermoplastic Starch Blends for Tissue Engineering Application

Cell Transplantation, 2021

Complex in vitro characterization of a blended material based on Poly(Lactic Acid), Poly(Hydroxyb... more Complex in vitro characterization of a blended material based on Poly(Lactic Acid), Poly(Hydroxybutyrate), and Thermoplastic Starch (PLA/PHB/TPS) was performed in order to evaluate its potential for application in the field of tissue engineering. We focused on the biological behavior of the material as well as its mechanical and morphological properties. We also focused on the potential of the blend to be processed by the 3D printer which would allow the fabrication of the custom-made scaffold. Several blends recipes were prepared and characterized. This material was then studied in the context of scaffold fabrication. Scaffold porosity, wettability, and cell-scaffold interaction were evaluated as well. MTT test and the direct contact cytotoxicity test were applied in order to evaluate the toxic potential of the blended material. Biocompatibility studies were performed on the human chondrocytes. According to our results, we assume that material had no toxic effect on the cell cultur...

Research paper thumbnail of Printability, Mechanical and Thermal Properties of Poly(3-Hydroxybutyrate)-Poly(Lactic Acid)-Plasticizer Blends for Three-Dimensional (3D) Printing

Materials, 2020

This paper investigates the effect of plasticizer structure on especially the printability and me... more This paper investigates the effect of plasticizer structure on especially the printability and mechanical and thermal properties of poly(3-hydroxybutyrate)-poly(lactic acid)-plasticizer biodegradable blends. Three plasticizers, acetyl tris(2-ethylhexyl) citrate, tris(2-ethylhexyl) citrate, and poly(ethylene glycol)bis(2-ethylhexanoate), were first checked whether they were miscible with poly(3-hydroxybutyrate)-poly(lactic acid) (PHB-PLA) blends using a kneading machine. PHB-PLA-plasticizer blends of 60-25-15 (wt.%) were then prepared using a corotating meshing twin-screw extruder, and a single screw extruder was used for filament preparation for further three-dimensional (3D) fused deposition modeling (FDM) printing. These innovative eco-friendly PHB-PLA-plasticizer blends were created with a majority of PHB, and therefore, poor mechanical properties and thermal properties of neat PHB-PLA blends were improved by adding appropriate plasticizer. The plasticizer also influences the pri...

Research paper thumbnail of Erratum: Influence of Composition and Plasma Power on Properties of Film from Biodegradable Polymer Blends. Polymers 2020, 12, 1592

Polymers, 2020

The authors wish to make a change to the published paper [...]

Research paper thumbnail of Influence of Composition and Plasma Power on Properties of Film from Biodegradable Polymer Blends

Polymers, 2020

The work is focused on the study of surface plasma treatment (DCSBD) of films from biodegradable ... more The work is focused on the study of surface plasma treatment (DCSBD) of films from biodegradable polymers from renewable sources based on polylactic acid (PLA) and polyhydroxybutyrate (PHB). A 4-factor design of experiment was used where the selected variable parameters were the plasma device power, the time of plasma treatment, the ratio of PHB in the polymer blend with PLA, and the content of acetyl tributyl citrate (ATBC) plasticizer in the PLA + PHB blend. The surface total energy and the polar component were evaluated immediately after surface plasma treatment and after 5 h of sitting. Topography of foil surfaces was also studied by AFM. In terms of plasma power and activation time, the greatest increase in surface energy values was observed with a short plasma time of 2 s and a high power of 400 W. Increasing the content of ATBC in interaction with the high concentration of PHB in the blend results in a reduction in the difference of both the polar component and the total free...

Research paper thumbnail of Low frequency electromagnetic shielding efficiency of composites based on ethylene propylene diene monomer and multi‐walled carbon nanotubes

Polymers for Advanced Technologies, 2020

Ethylene propylene diene monomer rubber was filled with multi‐walled carbon nanotubes to prepare ... more Ethylene propylene diene monomer rubber was filled with multi‐walled carbon nanotubes to prepare composite materials with the effect of electromagnetic radiation (EMR) shielding. Sulfur‐based curing system as well as peroxide curing system were used for vulcanization of rubber compounds. The main goal of the work was the investigation of curing system composition and filler content on curing process, physical‐mechanical properties, cross‐link density, and shielding efficiency of the prepared composites. The results showed that curing characteristics and cross‐link density of composites were dependent on both, amount of carbon nanotubes and curing system composition. The incorporation of filler resulted in the enhancement of physical‐mechanical properties of composites. Higher values of tensile strength were found to have composites cured with organic peroxide in combination with co‐agent. The achieved results also demonstrated that carbon nanotubes filled rubber composites are suita...

Research paper thumbnail of Mechanical testing of hydroxyapatite filaments for tissue scaffolds preparation by fused deposition of ceramics

Journal of the European Ceramic Society, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Research paper thumbnail of The influence of additives on crystallization of blends based on polylactid acid

IOP Conference Series: Materials Science and Engineering, 2017

The sustainable development consists of the effort of replacing commonly used polymer materials f... more The sustainable development consists of the effort of replacing commonly used polymer materials for the biodegradable ones. They do not have sufficient physical and mechanical properties, therefore they have to be modified by producing various ratio mixtures or with the additives. Improving their processability and properties is an important challenge to be afforded before using these materials on the market. One way to improve the properties of these materials is to prepare their blends [1]. The most common way of the preparation of packaging materials is the injection moulding, where the crystallization of material is very important. That is the reason the crystallization has become one of the most studied characteristics of biodegradable blends based on PLA / PHB. The work is a contribution to works that deal with the description of the structure of PLA / PHB blends, which have been modified by the addition of various types of additives, mainly nucleating agents and plasticizers [2]. The films of these blends keep approximately unchanged mechanical properties after two weeks of storage. The presence of plasticizer (ATBC) and nucleating agent (BN) has no significant impact on the processing stability of PLA/PHB blends. The results show that the combination of the plasticizer and nucleating agent greatly affects the process of crystallization of PLA/PHB blends as well as the ratio of polymers and the heat treatment process.

Research paper thumbnail of Effect of PHB on the properties of biodegradable PLA blends

Chemical Papers, 2016

Blends of biodegradable polymers polylactic acid/thermoplastic starch/polyhydroxybutyrate (PLA/TP... more Blends of biodegradable polymers polylactic acid/thermoplastic starch/polyhydroxybutyrate (PLA/TPS/PHB) were prepared using a twin-screw extruder. The TPS content was constant (50 %) and the PHB content in the blends was gradually changed from 0 mass % to 20 mass %. TPS was prepared by melting, where a mixture of native starch, water and glycerol was fed into the twin-screw extruder. Average temperature of extrusion was 180 °C and the concentration of glycerol was 40 mass %. Influence of the PHB concentration in the blend and that of the processing technology on the mechanical and rheological properties of the PLA/PHB composition containing TPS were studied. Mechanical properties were measured 24 h after the film and monofilament preparation and also after the specific storage time to study the effect of storage on the properties. The results indicate that differences in morphology strongly influence the mechanical properties of the studied materials with identical material composit...

Research paper thumbnail of Biologically Degradable Polymeric Composition with High Deformability

Research paper thumbnail of Oscillation rheometry – method for processing stability testing of high sensitive polymers

AIP Conference Proceedings, 2015

This work introduces the oscillation rheometry as a method for determination of processing stabil... more This work introduces the oscillation rheometry as a method for determination of processing stability of polymers, which are high sensitive to degradation during melt processing. The oscillation rheometry was found as a simple and rapid method which could indicate the first stages of degradation process. Changes in relative complex viscosity were taken as indicator of processing stability. It was shown that changes in relative complex viscosity reflect changes in molecular weight of degraded polymer very well.

Research paper thumbnail of Recycling possibilities of bioplastics based on PLA/PHB blends

Polymer Testing, 2020

The study is focused on modelling the evaluation of recyclability of the biodegradable blend usin... more The study is focused on modelling the evaluation of recyclability of the biodegradable blend using multiple extrusion of selected composition of PLA/PHB blend which had been more deeply studied before. It was shown that the multiple extrusion reduces viscosity of the tested blend due to multiple thermomechanical stresses and the material was partially degraded. Partial degradation was demonstrated by measuring of molecular characteristics. The degree of degradation of the tested material was determined with relatively high accuracy after creating a colour space/viscosity. Multiple processing and subsequent degradation of the tested material did not negatively affect thermal properties, as well as strength characteristics of the blend. It was concluded that the biodegradable polymer blend of the PLA/PHB type is suitable for multiple processing and material recycling can be applied for this type of bioplastics.