(Bio)plastics Kudělová Eva Majerová Hana Petrochemical plastics - The most common types of plastics: Polyethylene (PE) Polyvinylchloride (PVC) Polypropylene (PP) Polyurethane (PU) 2 The issue of the plastics - Environment - not a well-established system that can deal with the huge quantity of generated pollutants - the petroleum is not renewable and a scarce source - transition to a bio-based and biodegradable plastics 3 The issue of the plastics - Economy - The linear plastic system - based on “Take-Make-Dispose” - 3 ways for the disposal of plastic ● mechanical recycling ● landfilling ● incinerating - The circular plastic system - based on “Closed-Loop Economy” - Reducing, Reusing, Recycling 4 The issue of the plastics - Effect on Health - intake of around 250 grams of microplastics per year - the pigmented microplastics were found in 4 placentas out of 6 - possible the transgenerational effect on metabolism and reproduction #1 - oxide yellow; #2, #3, #10 - copper phthalocyanine; #4 - violanthrone 5 Bioplastics 2 types based on degradability: a) Non-biodegradable (Bio-based) - biological origin but not biodegradable include - completely similar properties to traditional plastics - made from natural materials - starches will be converted into ethanol - then synthesized to ethylene/propylene - polymerization to traditional PE and PP plastics a) b) Biodegradable - completely transformed into CO2 , H2 0, biomass - PLA (polylactic acid) - biological raw material - the production of plant starches - PHAs (polyhydroxyalkanoates) - microbial origin 6 Polyhydroxyalkanoates (PHAs) - good candidates in replacement of petrochemical plastics - biodegradable, biocompatible, renewable, sustainable - similar properties with conventional plastics - synthesized by prokaryotes under conditions with high content of carbon source and limited nutrients (nitrogen) - PHA granules functions - carbon and energy storage - stress resistance (UV radiations, high temperatures, etc.) 7 Polyhydroxyalkanoates - mechanical and technological properties of PHAs depend on the monomer composition - homopolymers (PHB) - copolymers (PHBV) - generally better properties - production of bioplastics in 2020 was 2.11 million tons, which is less than 1% of the total annual production of plastics (368 million tons in 2020) - only 1.7% of the bioplastics produced in 2020 were PHAs - issues: 1. high production cost 2. limited polymer diversity 8 Substrates - its choice depends mainly on the organism metabolic routes, substrate cost and availability - different substrates lead to specific types of PHAs - affects polymer properties and its applications Oils and sugars from agriculture plants: starch-based crops, sugarcane, beetroot,... Waste materials like lignocellulosic biomass, waste oils, wastewater, spent coffee grounds,... - lignocellulosic - very popular in last years, but its pretreatment can be tricky Inorganic substrates - CO2 9 Metabolism Main pathways: 1. 3 reactions catalyzed by PhaA, PhaB and PhaC 2. ß-oxidation of fatty acids 3. fatty acids de novo synthesis Important enzymes: - PHA synthase (PhaC) - connects all pathways - polymerization - PHA depolymerase - degradation - extracellular and intracellular 10 PHAs in Agriculture - can be used to make soil friendly compostable greenhouse films - mulch aids in better soil integrity, pollution control, moisture retention, and weed control 11 PHAs in Medical Devices - Implant material - biodegradable, biocompatible, nontoxic - tissue friendly with blood, bone and human cell lines - Various therapeutics - cardiovascular patches ■ providing repair and support to the infarcted tissue post myocardial infarction - wound dressing ■ can reduce the inflammation, enhance the angiogenic properties of the skin, and facilitate its healing - 3D custom-made bone marrow scaffolds ■ combine 3D printed bone tissue engineering scaffolds with stem cells 12 PHA as a Coating Agent - their distinctive characteristics suggest a potential application as a softener in biopolymeric blends - water resistant makes them perfect for packaging materials such as milk cartons, sanitary towels, shampoo bottles etc. - antimicrobial PHA materials containing silver nanoparticles 13 Thank you for your attention!