GREENFILS – DEVELOPMENT OF 100% BIODEGRADABLE YARNS, FUNCTIONALISED THROUGH REACTIVE EXTRUSION.
At the start of the third millennium, the world population was approximately six billion, which is expected to rise to ten billion by the middle of the twenty-first century. The exponential increase in population increases the demand on food, energy, water, resources and chemicals, which effects a corresponding increase in environmental pollution and a depletion of finite resources (e.g. fossil fuels). Oil–based polymer materials have been known for more than 90 years and a lot of applications have been found for them, ranging from simple packaging to medicine, and they play an important role in the improvement and quality of human modern life.
The main problems of synthetic polymers are the non-degradable and non-renewable ability, generating accumulation of waste which are difficult to manage. Besides the atmospheric emissions derived from the obtention process. Therefore, in a world that is becoming increasingly sensitive to the need to protect our environment, the ability to manufacture products from sustainable resources and which are fully compostable at the end of their useful life, is an exciting and attractive proposition (Figure 1).
Thus, PLA and PHB biopolymers are regarded as ones of the most promising bio-based and biodegradable polymers, due to its excellent biodegradability, biocompatibility, renewability, high strength, and easy processability. However, disadvantages such as brittleness and relatively high cost have significantly restricted its applications. Thus, reactive extrusion is a novel, cost-effective and environmentally-friendly method to produce new biodegradable textiles with enhanced performance properties by surface modification/functionalization or chemical bonding of two (or more) immiscible polymers.
The main objective is to obtain 100% biodegradable yarns, chemically modified by means of reactive extrusion, with improved mechanical and thermal properties. Next, the specific objectives are listed:
- Monofilament extrusion of biodegradable/compostable polymers (PLA y PHB)
- Tape extrusion process to perform compostability studies of PLA and PHB. Comparative between PLA, which is commercially available, and PHB.
- Multifilament extrusion, by monofilament extruder, of PHB and PLA polymers (pilot plant).
- Multifilament extrusion, by multifilament extruder, of PHB and PLA polymers (semi-industrial scale).
- Reactive extrusion of PHB and PLA to improve its thermal and mechanical properties.
- Reactive extrusion of PHB to increase the decomposition temperature of the polymer, in order to improve the melt spinning process.
- Reactive extrusion of PLA to rise its softening temperature (VICAT) from de 60°C to 90°C, which extends its field application.
- Monofilament and multifilament extrusion processes of the novel functionalized polymers.
Traditional extrusion process, based on physical blending, is defined as simple mixing in the melt state without chemical reactions between components, which usually results in weak interfacial adhesion between phases and leads to unsatisfactory physico-mechanical properties of obtained polymeric materials, which strongly limits their further applications. Therefore, most of bio-based polymer blends and composites require further compatibilization.
Hence, thanks to reactive extrusion, stable and irreversible materials with tuneable properties can be prepared by judicious incorporation of compatibilizers, monomers and inorganic nanoparticles. More specifically, the incorporation of metallic nanoparticles, such as titanium, aluminium or silicon, as well as surface modification by grafting employing functional metallic alkoxides as precursors, increases the thermal and mechanical properties of the biopolymers/nanocomposites, which allows to overcome their main limitations. Therefore, the obtention of stable and modified/functionalized biopolymers will enhance the spinning process and extend its field application improving their competitivity in the market.
This project is funded by the Conselleria d’Economia Sostenible, Sectors Productius, Comerç i Treball de la Generalitat Valenciana, through IVACE.
GRANT NUMBER: IMAMCI/2019/1
MORE INFORMATION IN THE NON-ECONOMIC ACTIVITIES PLAN
- Year: 2019
- Status: Finished
- Entity: IVACE