14 documents found, page 1 of 2
Biodegradation in Soil of the PHB/Wood Flour (80/20) and PHB/Sisal Fiber (80/20...
Casarin,Suzan Aline; Rodrigues,Cássia Priscila; Souza Júnior,Osvaldo Francisco de; Rosário,Francisco; Agnelli,José Augusto MarcondesThis paper presents the results of a study that aimed to monitor and evaluate biodegradation in soil, by the mass loss and the mechanical properties of plastic tubes. For this work, there were extruded and injected plastic tubes made of biodegradable polymer poly(hydroxybutyrate) - (PHB) and composite PHB/Wood Flour and PHB/Sisal Fiber, both with 20% fiber. There were used three biodegradation test devices for ...
Reprocessability of PHB in extrusion: ATR-FTIR, tensile tests and thermal studies
Rivas,Leonardo Fábio; Casarin,Suzan Aline; Nepomuceno,Neymara Cavalcante; Alencar,Marie Isabele; Agnelli,José Augusto MarcondesAbstract Mechanical recycling of biodegradable plastics has to be encouraged, since the consumption of energy and raw materials can be reduced towards a sustainable development in plastics materials. In this study, the evolution of thermal and mechanical properties, as well as structural changes of poly(hydroxybutyrate) (PHB) up to three extrusion cycles were investigated. Results indicated a significant reduct...
Estudo da miscibilidade das misturas de PHB e PLA, com um PHB de alta polidispe...
Pachekoski,Wagner Mauricio; Dalmolin,Carla; Agnelli,José Augusto MarcondesNeste trabalho, foi estudada a miscibilidade de misturas de um PHB constituído de frações de alta e baixa massa molar com um PLA de alta massa molar. Os materiais extrudados foram analisados pelas técnicas de calorimetria exploratória diferencial (DSC), espectroscopia dielétrica (DE) e análises dinâmico-mecânicas (DMA). A partir dos resultados observou-se o distinto comportamento cristalino das frações de PHB, ...
Avaliação de sistemas pró-degradantes na degradação termooxidativa do PEAD
Babetto,Alex Sandro; Agnelli,José Augusto Marcondes; Bettini,Sílvia Helena PradoResumo Sistemas pró-degradantes fundamentados em estearatos de ferro e de manganês e o aditivo comercial d2w, fundamentado em sal orgânico de manganês, foram avaliados em filmes de polietileno de alta densidade (PEAD) em ambiente termooxidativo (estufa a 80 °C e ausência de luz). A degradação termooxidativa foi monitorada por propriedades mecânicas, espectroscopia de infravermelho e cromatografia por exclusão d...
Synthesis and photostabilizing performance of a polymeric HALS based on 1,2,2,6...
Chinelatto,Marcelo Aparecido; Agnelli,José Augusto Marcondes; Canevarolo,Sebastião VicentePolymeric hindered amine light stabilizers (polymeric HALS) have been extensively studied because they combine a high ability to protect the polymers against harmful effects of weathering with minimum physical loss. In this study a new polymeric N-methylated HALS was synthesized by the radical copolymerization of a cyclic tertiary amine with vinyl acetate (VAc). 4-Acryloyloxy-1,2,2,6,6-pentamethylpiperidine (AP...
Addition of Silver Nanoparticles to Composite Resin: Effect on Physical and Bac...
Neves,Patrícia Bolzan Agnelli das; Agnelli,José Augusto Marcondes; Kurachi,Cristina; Souza,Clovis Wesley Oliveira deThe objectives of this study were to evaluate physical properties and antibacterial activity of a light-activated composite modified with silver nanoparticles. Discs were produced with unmodified resin (control group - CG) and modified resin with silver nanoparticles at two concentrations, 0.3% wt (MR03) and 0.6% wt (MR06). Streptococcus mutans and Lactobacillus acidophilus biofilms were induced in vitro by inc...
Synthesis and characterization of copolymers from hindered amines and vinyl mon...
Chinelatto,Marcelo Aparecido; Agnelli,José Augusto Marcondes; Canevarolo,Sebastião VicenteNew copolymers from hindered amines and vinyl monomers were synthesized by radical chain polymerization. To obtain polymeric HALS, acrylamide-(1ATP) and acrylate-(4ATP) monomers, derivatives from 2,2,6,6-tetramethylpiperidine and 2,2,6,6-tetramethyl-4-piperidinol were synthesized. The radical chain polymerization of 1ATP with styrene (Sty) using 1-butanethiol (BTN) resulted in a copolymer with 95 units of Sty a...
Blendas poliméricas biodegradáveis de PHB e PLA para fabricação de filmes
Pachekoski,Wagner Mauricio; Dalmolin,Carla; Agnelli,José Augusto MarcondesO poli(hidroxibutirato) - PHB - e o poli(ácido lático) - PLA - são dois poliésteres termoplásticos com grande potencial para uso em aplicações industriais, sendo viáveis nos principais métodos de processamento e totalmente biodegradáveis. Porém, devido às suas propriedades mecânicas limitadas, necessitam de modificações para melhorar seu desempenho e tornarem-se industrialmente competitivos. Foram estudadas pro...
Natural additives for poly (hydroxybutyrate - CO - hydroxyvalerate) - PHBV: eff...
Brunel,Daiane Gomes; Pachekoski,Wagner Maurício; Dalmolin,Carla; Agnelli,José Augusto MarcondesIn this work, the improvement of mechanical properties in biodegradable materials was obtained through the incorporation of natural and also biodegradable plasticizers and nucleation agents into the PHBV copolymer. PHBV production with different quantities of additives was obtained by extrusion followed by injection. The additives in the copolymer were efficient, resulting in an adequate processing due to the p...
The influence of the industrial processing on the degradation of poly(hidroxybu...
Pachekoski,Wagner Maurício; Dalmolin,Carla; Agnelli,José Augusto MarcondesPHB was characterized after different industrial processes by Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), Melt Flow Index (MFI), Complex Dielectric Relaxation (CDR) and Size Exclusion Chromatography (SEC). Some properties of PHB were investigated before and after processing, in order to understand how temperature and other extrusion or injection conditions affect the...