Green composites based on (waste) cork

Posljednjih godina sve je veći interes za materijalima koji proizlaze iz obnovljivih izvora, uglavnom zbog sve veće zabrinutosti povezane s onečišćenjem okoliša, nakupljanjem otpada, njegovim odlaganjem kao i neizbježnog iscrpljivanja fosilnih izvora. Termoplastični biorazgradivi polimer polilaktid (PLA) nameće se kao izvrstan izbor te održiva alternativa petrokemijskim proizvodima. S druge strane, prirodno punilo pluto koje se dobiva od vanjske kore hrasta plutnjaka ima jedinstvenu kombinaciju svojstava kao što je niska gustoća, izvrsna akustična i toplinska svojstva, nepropusnost za tekućine i plinove, elastičnost što ga čini izvrsnim kandidatom za razne primjene. Osim toga pluto je prirodni i obnovljiv proizvod koji nudi jedinstven izgled i teško mu može parirati bilo koji sintetski materijal. Zeleni kompoziti na bazi pluta održivi su materijali s potencijalnom primjenom u raznim područjima kao što su automobilska industrija (kompozitni paneli) te u građevinarstvu (podovi i izolacijske ploče). U ovom radu pripremljeni su zeleni kompoziti odnosno biokompoziti na bazi pluta i biorazgradive matrice polilaktida jednostavnim umješavanjem u Brabender gnjetilici, te prešanjem na hidrauličkoj preši. Toplinska svojstva biokompozita ispitana su diferencijalnom pretražnom kalorimetrijom (DSC), termogravimetrijskom analizom (TGA) i mjerenjem toplinske vodljivosti. Mehanička svojstva ispitana su jednoosnim rasteznim ispitivanjem na mehaničkoj kidalici. Provedena je i analiza površinskih svojstava primjenom kontaktnog kuta kako bi se dobio uvid u interakcije na međupovršini PLA/pluta kompozita.In recent years, there has been an increasing interest in materials derived from renewable sources, mainly due to growing concerns related to environmental pollution, waste accumulation and its disposal, as well as the inevitable depletion of fossil resources. The thermoplastic biodegradable polymer polylactide (PLA) is emerging as an excellent choice and a sustainable alternative to petrochemical products. On the other hand, the natural cork filler obtained from the outer bark of cork oak has a unique combination of properties. Low density, excellent acoustic and thermal properties, impermeability to liquids and gases and elasticity makes it excellent candidate for various applications. In addition, cork is a natural and renewable product that offers a unique look that cannot be matched by any synthetic material. Cork-based green composites are sustainable materials with potential applications in various fields such as automotive industry (composite panels) and construction (flooring and insulation panels). In this work, green composites or biocomposites based on cork and biodegradable polylactide matrix were prepared by simple mixing in a Brabender's kneader and pressing on a hydraulic press. The thermal properties of biocomposites were tested by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and thermal conductivity measurement. The mechanical properties were tested by uniaxial tensile testing on a mechanical tear machine. An analysis of the surface properties using the contact angle was also carried out in order to gain insight into the interactions at the PLA/cork composite interface

Aluminate cement

U ovom radu prikazan je proces proizvodnje aluminatnog cementa u tvrtki Calucem d.o.o. (Pula, Hrvatska), koja je po proizvodnji druga na svjetskom tržištu. Posebna svojstva aluminatnog cementa posljedica su kemijskog i mineralog sastava u kojem dominiraju kalcijevi aluminati kao glavni hidratno aktivni minerali koji omogućuju brzi razvoj čvrstoće. Opisan je tijek hidratacije aluminatnog cementa i nastanak metastabilnih i stabilnih produkata hidratacije i razvoj mikrostrukture cementnog kompozita. Aluminatni cement primjenjuje se u građevinskoj kemiji i građevini, industriji vatrostalnih materijala i drugim specijalnim primjenama.This work describes the process of manufacturing aluminate cement in the company of Calucem d. o. o. (Pula, Croatia), which is the second largest manufacturer in the world market. Unique properties that make aluminate cement special chemical and mineral composition, which is dominated primarily by monocalcium aluminate as the main hidrate-active mineral, which further potentiates rapid development of solidity. Also, hydration process of aluminate cement and the formation of metastable and stable hydration products and the development of the microstructure of the cement composite are described in this work. Aluminate cement is used in building chemistry and construction industry, the refractory industry and other specialty applications

Green composites based on (waste) cork

Posljednjih godina sve je veći interes za materijalima koji proizlaze iz obnovljivih izvora, uglavnom zbog sve veće zabrinutosti povezane s onečišćenjem okoliša, nakupljanjem otpada, njegovim odlaganjem kao i neizbježnog iscrpljivanja fosilnih izvora. Termoplastični biorazgradivi polimer polilaktid (PLA) nameće se kao izvrstan izbor te održiva alternativa petrokemijskim proizvodima. S druge strane, prirodno punilo pluto koje se dobiva od vanjske kore hrasta plutnjaka ima jedinstvenu kombinaciju svojstava kao što je niska gustoća, izvrsna akustična i toplinska svojstva, nepropusnost za tekućine i plinove, elastičnost što ga čini izvrsnim kandidatom za razne primjene. Osim toga pluto je prirodni i obnovljiv proizvod koji nudi jedinstven izgled i teško mu može parirati bilo koji sintetski materijal. Zeleni kompoziti na bazi pluta održivi su materijali s potencijalnom primjenom u raznim područjima kao što su automobilska industrija (kompozitni paneli) te u građevinarstvu (podovi i izolacijske ploče). U ovom radu pripremljeni su zeleni kompoziti odnosno biokompoziti na bazi pluta i biorazgradive matrice polilaktida jednostavnim umješavanjem u Brabender gnjetilici, te prešanjem na hidrauličkoj preši. Toplinska svojstva biokompozita ispitana su diferencijalnom pretražnom kalorimetrijom (DSC), termogravimetrijskom analizom (TGA) i mjerenjem toplinske vodljivosti. Mehanička svojstva ispitana su jednoosnim rasteznim ispitivanjem na mehaničkoj kidalici. Provedena je i analiza površinskih svojstava primjenom kontaktnog kuta kako bi se dobio uvid u interakcije na međupovršini PLA/pluta kompozita.In recent years, there has been an increasing interest in materials derived from renewable sources, mainly due to growing concerns related to environmental pollution, waste accumulation and its disposal, as well as the inevitable depletion of fossil resources. The thermoplastic biodegradable polymer polylactide (PLA) is emerging as an excellent choice and a sustainable alternative to petrochemical products. On the other hand, the natural cork filler obtained from the outer bark of cork oak has a unique combination of properties. Low density, excellent acoustic and thermal properties, impermeability to liquids and gases and elasticity makes it excellent candidate for various applications. In addition, cork is a natural and renewable product that offers a unique look that cannot be matched by any synthetic material. Cork-based green composites are sustainable materials with potential applications in various fields such as automotive industry (composite panels) and construction (flooring and insulation panels). In this work, green composites or biocomposites based on cork and biodegradable polylactide matrix were prepared by simple mixing in a Brabender's kneader and pressing on a hydraulic press. The thermal properties of biocomposites were tested by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and thermal conductivity measurement. The mechanical properties were tested by uniaxial tensile testing on a mechanical tear machine. An analysis of the surface properties using the contact angle was also carried out in order to gain insight into the interactions at the PLA/cork composite interface

Aluminate cement

U ovom radu prikazan je proces proizvodnje aluminatnog cementa u tvrtki Calucem d.o.o. (Pula, Hrvatska), koja je po proizvodnji druga na svjetskom tržištu. Posebna svojstva aluminatnog cementa posljedica su kemijskog i mineralog sastava u kojem dominiraju kalcijevi aluminati kao glavni hidratno aktivni minerali koji omogućuju brzi razvoj čvrstoće. Opisan je tijek hidratacije aluminatnog cementa i nastanak metastabilnih i stabilnih produkata hidratacije i razvoj mikrostrukture cementnog kompozita. Aluminatni cement primjenjuje se u građevinskoj kemiji i građevini, industriji vatrostalnih materijala i drugim specijalnim primjenama.This work describes the process of manufacturing aluminate cement in the company of Calucem d. o. o. (Pula, Croatia), which is the second largest manufacturer in the world market. Unique properties that make aluminate cement special chemical and mineral composition, which is dominated primarily by monocalcium aluminate as the main hidrate-active mineral, which further potentiates rapid development of solidity. Also, hydration process of aluminate cement and the formation of metastable and stable hydration products and the development of the microstructure of the cement composite are described in this work. Aluminate cement is used in building chemistry and construction industry, the refractory industry and other specialty applications

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Green composites based on (waste) cork

Posljednjih godina sve je veći interes za materijalima koji proizlaze iz obnovljivih izvora, uglavnom zbog sve veće zabrinutosti povezane s onečišćenjem okoliša, nakupljanjem otpada, njegovim odlaganjem kao i neizbježnog iscrpljivanja fosilnih izvora. Termoplastični biorazgradivi polimer polilaktid (PLA) nameće se kao izvrstan izbor te održiva alternativa petrokemijskim proizvodima. S druge strane, prirodno punilo pluto koje se dobiva od vanjske kore hrasta plutnjaka ima jedinstvenu kombinaciju svojstava kao što je niska gustoća, izvrsna akustična i toplinska svojstva, nepropusnost za tekućine i plinove, elastičnost što ga čini izvrsnim kandidatom za razne primjene. Osim toga pluto je prirodni i obnovljiv proizvod koji nudi jedinstven izgled i teško mu može parirati bilo koji sintetski materijal. Zeleni kompoziti na bazi pluta održivi su materijali s potencijalnom primjenom u raznim područjima kao što su automobilska industrija (kompozitni paneli) te u građevinarstvu (podovi i izolacijske ploče). U ovom radu pripremljeni su zeleni kompoziti odnosno biokompoziti na bazi pluta i biorazgradive matrice polilaktida jednostavnim umješavanjem u Brabender gnjetilici, te prešanjem na hidrauličkoj preši. Toplinska svojstva biokompozita ispitana su diferencijalnom pretražnom kalorimetrijom (DSC), termogravimetrijskom analizom (TGA) i mjerenjem toplinske vodljivosti. Mehanička svojstva ispitana su jednoosnim rasteznim ispitivanjem na mehaničkoj kidalici. Provedena je i analiza površinskih svojstava primjenom kontaktnog kuta kako bi se dobio uvid u interakcije na međupovršini PLA/pluta kompozita.In recent years, there has been an increasing interest in materials derived from renewable sources, mainly due to growing concerns related to environmental pollution, waste accumulation and its disposal, as well as the inevitable depletion of fossil resources. The thermoplastic biodegradable polymer polylactide (PLA) is emerging as an excellent choice and a sustainable alternative to petrochemical products. On the other hand, the natural cork filler obtained from the outer bark of cork oak has a unique combination of properties. Low density, excellent acoustic and thermal properties, impermeability to liquids and gases and elasticity makes it excellent candidate for various applications. In addition, cork is a natural and renewable product that offers a unique look that cannot be matched by any synthetic material. Cork-based green composites are sustainable materials with potential applications in various fields such as automotive industry (composite panels) and construction (flooring and insulation panels). In this work, green composites or biocomposites based on cork and biodegradable polylactide matrix were prepared by simple mixing in a Brabender's kneader and pressing on a hydraulic press. The thermal properties of biocomposites were tested by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and thermal conductivity measurement. The mechanical properties were tested by uniaxial tensile testing on a mechanical tear machine. An analysis of the surface properties using the contact angle was also carried out in order to gain insight into the interactions at the PLA/cork composite interface

Aluminate cement

U ovom radu prikazan je proces proizvodnje aluminatnog cementa u tvrtki Calucem d.o.o. (Pula, Hrvatska), koja je po proizvodnji druga na svjetskom tržištu. Posebna svojstva aluminatnog cementa posljedica su kemijskog i mineralog sastava u kojem dominiraju kalcijevi aluminati kao glavni hidratno aktivni minerali koji omogućuju brzi razvoj čvrstoće. Opisan je tijek hidratacije aluminatnog cementa i nastanak metastabilnih i stabilnih produkata hidratacije i razvoj mikrostrukture cementnog kompozita. Aluminatni cement primjenjuje se u građevinskoj kemiji i građevini, industriji vatrostalnih materijala i drugim specijalnim primjenama.This work describes the process of manufacturing aluminate cement in the company of Calucem d. o. o. (Pula, Croatia), which is the second largest manufacturer in the world market. Unique properties that make aluminate cement special chemical and mineral composition, which is dominated primarily by monocalcium aluminate as the main hidrate-active mineral, which further potentiates rapid development of solidity. Also, hydration process of aluminate cement and the formation of metastable and stable hydration products and the development of the microstructure of the cement composite are described in this work. Aluminate cement is used in building chemistry and construction industry, the refractory industry and other specialty applications

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Ružička days : International conference 19th Ružička Days “Today Science – Tomorrow Industry” : Proceedings

Dear colleagues, we are extremely honoured to present to you the Proceedings of the international conference 19th Ružička Days, which was successfully held on September 21–23, 2022, in Vukovar, Croatia, in the hometown town of our famous Croatian scientist and first Nobel laureate, professor Leopold (Lavoslav) Ružička. The main goals of the Conference were to promote excellence, originality and innovation of interdisciplinary scientific research as well as the practical application of the obtained results through collaboration with industry, emphasizing thus the recognizable slogan of the Ružička Days conference: "Today Science – Tomorrow Industry". In addition, the Conference gave the opportunity for meetings, exchanging the ideas, opinions, experiences and cooperation among participants from different working surroundings. It is also important to point out that since 2008, within the international conference Ružička Days, Meeting of Young Chemists has also been held, where high school students, with the help of their mentors, present papers in the field of chemistry, with the aim to direct students and young people to the technical and natural sciences, especially chemistry. In its seventh issue (2011, 2013, 2015, 2017, 2019, 2021) the Proceedings publishes scientific and professional full papers of high quality in the following sections: Chemical analysis and synthesis (10), Chemical and biochemical engineering (3), Food technology and biotechnology (4), Chemistry in agriculture and forestry (1), Environmental protection (9) and 8th Meeting of Young Chemists (3). Full-length papers were subjected to an international review procedure done by eminent experts from the corresponding fields, to whom we express our gratitude, but they were not subjected to linguistic proofreading. On behalf of the Scientific and Organizing Committee of the 19th Ružička Days we cordially thank all the authors, reviewers, participants, lecturers, organizers, especially the international organizers EuCheMS and EHEDG, auspices and sponsors, and all the others who, in any way, supported the Conference and contributed to the preparation of the Proceedings, especially to our highly skilled and committed associates, who have put a lot of effort in the preparation of these Proceedings. At the very end, special thanks to our young, future scientists and their mentors who are faithful participants of the Meeting of Young Chemists of the Ružička Days conference. Enjoy the extremely interesting scientific and professional papers contained in these Proceedings, until the next 20th jubilee of Ružička Days in 2024! We are looking forward to meeting you again in Vukovar! Yours sincerely, Chief Editors Jurislav Babić Vesna Ocelić Bulatović Dajana Kučić Grgi