24 research outputs found
Flammability and Thermal Properties of Rigid Polyurethane Foams Containing Wheat Straw Lignin
Due to development of new generation of biomass processing, the examination of novel lignin products for creation of lignin-containing PU remains actual up to now. For preparation of lignin containing PU in this study a novel BIOLIGNIN was used. BIOLIGNIN is extracted from wheat straw in organic acid media using biomass refinery technology. The influence of chemically non-modified BIOLIGNIN and oxypropylated BIOLIGNIN on flammability and thermal properties in rigid PU foams was studied. Improvement of flame resistance and thermal stability is observed if chemically non-modified lignin as well as oxypropylated lignin is used
Rigid Polyurethane Foams From Oxypropylated Wheat Straw Lignin
Polyols for rigid PU foams production are derived mostly from petrochemical products but it can be replaced by polyols obtained from natural raw materials (vegetable oils, tall oil, lignin etc.). Organosolve lignin from CIMV biorefinery (France) was used in our work. Different lignin and propylene oxide (PO) ratio (0.15-0.40) was used to get lignopolyols. Commercial polyol Lupranol 3300 was substituted by each lignopolyol in the compositions of rigid PU foams to investigate lignopolyol effect to density, closed cell content, physical-mechanical properties and water absorption.
Lignopolyols synthesized from CIMV lignin by oxypropylation reaction is prospective material to obtain rigid PU foam with improved characteristics such as water absorption and compression strength
Thermal Degradation and Physical-mechanical Properties of Lignin-filled Rigid Polyurethane Foams
Nowadays, the synthesis of polymers from renewable resources, including polyurethane foams, has been actively investigated. In this work the potential application of lignin (CIMV, France) as non-reactive filler in tall oil amide (OH = 269 mg KOH/g, H2O = 0,2 wt.%) based rigid PU foams is studied.
It was concluded that introducing lignin to rigid PU foams systems can increase physico-mechanical properties of foams
Prevalence of Extended-spectrum beta-lactamase Producing Enterobacteriaceae Strains in Latvia
A total of 507 strains of the Enterobacteriaceae family were tested for the production of ESBL using mini API, ATB Expert system as a screening method, as well as the double disk method and E-test for confirmation. The prevalence of ESBL producing E. coli is 5.95%, Klebsiella spp. strains 37.7%. All ESBL- producing isolates are susceptible to imipenem and clavulanate. The susceptibility to other antimicrobials varies from 36 to 92%
Chimericwear : Blending Boundaries Between Digital and Physical Expressions in Fashion Design
The thesis bridges the gap between physical and digital print design in search of a hybrid state, reflecting our present time. With AI-assisted creativity in print development and features such as added volume to the print elements, the physical garments replicate the creation of a 3D object existing in computer software. Through innovative garment construction techniques and the development of photographic print composition, it redefines the relationship between print, form, and body. Driven by visually stimulating imagery and the desire to communicate physical sensation through concepts constructed via digital tools, the thesis proposes hybrid wearables existing in both the digital and physical states. The research examines an innovative symbiosis between the nostalgic past and the futuristic present with joyful expression in mind while simultaneously harmonizing the saturated voices of the current zeitgeist. The project contributes to the utilization of AI image-generating tools such as Dalle2 in the design practice and the role of maintaining human-centered design instead of replacing it. The results are presented in multitudes of different presentation formats from analog or digital ones in the forms of image stills and animation to phygital convergences between the virtual and the actual reality.
Chimericwear : Blending Boundaries Between Digital and Physical Expressions in Fashion Design
The thesis bridges the gap between physical and digital print design in search of a hybrid state, reflecting our present time. With AI-assisted creativity in print development and features such as added volume to the print elements, the physical garments replicate the creation of a 3D object existing in computer software. Through innovative garment construction techniques and the development of photographic print composition, it redefines the relationship between print, form, and body. Driven by visually stimulating imagery and the desire to communicate physical sensation through concepts constructed via digital tools, the thesis proposes hybrid wearables existing in both the digital and physical states. The research examines an innovative symbiosis between the nostalgic past and the futuristic present with joyful expression in mind while simultaneously harmonizing the saturated voices of the current zeitgeist. The project contributes to the utilization of AI image-generating tools such as Dalle2 in the design practice and the role of maintaining human-centered design instead of replacing it. The results are presented in multitudes of different presentation formats from analog or digital ones in the forms of image stills and animation to phygital convergences between the virtual and the actual reality.
Structure and Thermal Properties of Polyurethane Rigid Foams from Rapeseed Oil and Recycled Polyethylene Terephthalate
Lignin polyol in production of oil based polyurethane elastomers and rigid foams
Nowadays, due to economical and environmental concerns, polyurethane (PU) elastomer and rigid foam industry seeks ways to replace petrochemical polyols by renewable biomass. The aim of this study was to investigate lignin as a co-polyol in a solvent free production of castor oil based PU elastomers and tall oil amide based rigid PU foams. Lignin content correlation influence on PU elastomers and PU rigid foam physical-mechanical and morphological parameters were determinate