Biopolyethylene / polycaprolactone blends with different compatibilizing agents

A utilização de biopolímeros produzidos a partir de matérias-primas de fontes renováveis é considerada como possível solução para diminuição da poluição ambiental. O biopolietileno (Bio-PE) produzido a partir do etanol da cana-de-açúcar, surge como uma alternativa para o controle da poluição ambiental, desde que o mesmo não seja descartado de forma inadequada no meio ambiente. A policaprolactona (PCL) que se apresenta estável durante sua vida útil, pode ser degradada em um curto período de tempo, resultando na produção do CO2, água, minerais e matéria orgânica estabilizada. Este trabalho tem como objetivo a obtenção de blendas poliméricas de Bio-PE/PCL com copolímeros funcionalizados: polietileno enxertado com ácido acrílico (PEgAA) e polietileno enxertado com anidrido maleico (PEgMA). As blendas foram preparadas em extrusora de rosca dupla corrotacional, moldadas por injeção e caracterizadas por: reometria de torque, espectroscopia na região do infravermelho por transformada de Fourier (FTIR), difração de raios X (DRX), termogravimetria (TG), calorimetria exploratória diferencial (DSC) e microscopia eletrônica de varredura (MEV). As propriedades mecânicas e termomecânicas das blendas também foram avaliadas. Por reometria de torque, verificou-se que o PEgAA e o PEgMA foram reativos com a PCL, confirmadas por FTIR. Por DRX, verificou-se que a adição de diferentes teores de PCL e copolímeros funcionalizados não alteraram os padrões de difração do Bio-PE, bem como, o valor do pico da temperatura de fusão e de cristalização visto por DSC. Por TG, observou-se que as blendas exibiram uma menor estabilidade térmica. O valor da resistência à tração e do módulo de elasticidade das blendas binárias praticamente não foi alterado com o aumento do teor de PCL. Já a resistência ao impacto aumentou significativamente com a presença da PCL e dos copolímeros funcionalizados. Um aumento significativo no alongamento final das blendas ternárias foi observado. Por MEV, observou-se que o tamanho médio das partículas foi significativamente reduzido para as blendas compatibilizadas contendo baixos teores de PCL.The use of biopolymers produced from raw materials from renewable sources is considered as a possible solution to reduce environmental pollution. Biopolyethylene (Bio-PE) produced from ethanol from sugarcane emerges as an alternative to control environmental pollution, provided that it is not disposed of inappropriately in the environment. Polycaprolactone (PCL), which is stable during its useful life, can be degraded in a short period of time, resulting in the production of CO2, water, minerals and stabilized organic matter. This work aims to obtain polymer blends of Bio-PE/PCL with functionalized copolymers: polyethylene grafted with acrylic acid (PEgAA) and polyethylene grafted with maleic anhydride (PEgMA). The blends were prepared in a co-rotational twinscrew extruder, molded by injection and characterized by: torque rheometry, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetry (TG), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The mechanical and thermo-mechanical properties of the blends were also evaluated. By torque rheometry, it was found that PEgAA and PEgMA were reactive with PCL, confirmed by FTIR. FTIR spectra indicated possible chemical reactions between PCL and PEgAA or PEgMA. By XRD, it was found that the addition of different PCL and functionalized copolymer contents did not alter the Bio-PE diffraction patterns, as well as the peak melting temperature and crystallization value seen by DSC. By TG, it was observed that the blends exhibited lower thermal stability. The increase in PCL content practically did not alter the tensile strength and modulus of elasticity of the binary blends. However, there was an increase in the final elongation of the ternary blends in relation to the binary blends. However, the impact resistance increased significantly with the presence of PCL and functionalized copolymers. A significant increase in the final elongation of the ternary blends was observed. By MEV, it was observed that the average particle size was significantly reduced for compatibilized blends containing low levels of PCL

Obtaining PCL systems with a by-product of the cotton crop.

Estudos têm sido realizados com o intuito de criar processos que utilizem matérias-primas renováveis, gerando assim produtos não agressivos ao meio ambiente, sem perder em qualidade ou desempenho. Este trabalho teve como objetivo a obtenção de sistemas de poli(ε-caprolactona) (PCL) com subproduto da cultura algodoeira, a fim de avaliar a influência dos componentes línter e nanolínter de algodão nas propriedades finais dos compósitos poliméricos. Os sistemas de PCL com 1, 3 e 5% de cargas foram obtidos em extrusora e, processados em injetora, caracterizados quanto à composição lignocelulósica, tamanho de partícula e potencial zeta, difração de raios-X (DRX), termogravimetria (TG), calorimetria exploratória diferencial (DSC), microscopia eletrônica de varredura (MEV), propriedades mecânicas e temperatura de deflexão térmica (HDT). Por meio da caracterização lignocelulósica foi observado um alto teor de celulose para a fibra vegetal e, por medida do tamanho de partícula e potencial zeta, foram observadas partículas com diâmetro médio na faixa nanométrica. Por DRX, foi vista a presença dos picos característicos da PCL pura, do línter e da nanocelulose. Para os sistemas PCL/Línter e PCL/Nano não foram visualizadas alterações nos picos característicos da matriz. Por TG, foi verificada que a presença da carga não influenciou no comportamento térmico dos sistemas. Por DSC, não foram observadas alterações na cristalinidade dos sistemas com a presença do línter e do nanolínter. Por meio das fotomicrografias de MEV, foi observada a má adesão da matriz polimérica ao línter e ao nanolínter. Por meio dos ensaios de tração e flexão, foi observado que os sistemas com línter apresentaram um pequeno aumento no módulo e na resistência. Para os sistemas contendo nanolínter, os valores de módulo e de resistência foram similares aos da matriz. Por meio do ensaio de resistência ao impacto, foi observado que as cargas utilizadas diminuíram a resistência dos compósitos. Um aumento na temperatura de deflexão térmica (HDT) dos sistemas foi visto com a presença das cargas.Studies have been carried out with the aim of creating processes that use renewable raw materials, thus generating products that are not environmentally aggressive, without losing quality or performance. The aim of this work was to obtain poly (ε-caprolactone) (PCL) systems with a by-product of the cotton crop in order to evaluate the influence of cotton liner and nanolinter components on the final properties of the polymer composites. The PCL systems with 1, 3 and 5% of loading were obtained in an extruder and processed in injectors, characterized by lignocellulosic composition, particle size and zeta potential, X-ray diffraction (XRD), thermogravimetry (TG), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), mechanical properties and thermal deflection temperature (HDT). By means of the lignocellulosic characterization, a high cellulose content was observed for the vegetable fiber and, due to the particle size and zeta potential, particles with a mean diameter in the nano range were observed. By DRX, the peaks characteristic of pure PCL, linter and nanocellulose were observed. For PCL / Línter and PCL / Nano systems, no changes were seen in the characteristic peaks of the array. By TG, it was verified that the presence of the load did not influence the thermal behavior of the systems. By DSC, no changes were observed in the crystallinity of the systems with the presence of linter and nanolinter. By SEM photomicrographs, the poor adhesion of the polymer matrix to the linter and the nanolinter was observed. By means of the tensile and flexure tests, it was observed that the systems with linter presented a small increase in the modulus and the resistance. For systems containing nanolinter, the modulus and resistance values ​​were similar to those of the matrix. By means of the impact strength test, it was observed that the loads used decreased the resistance of the composites. An increase in the thermal deflection temperature (HDT) of the systems was seen with the presence of the charges

Toughening of polystyrene using styrene-butadiene rubber (SBRr) waste from the shoe industry

Abstract The vulcanized rubber waste from the shoe industry causes environmental damage when it is incinerated or inappropriately discarded, turning this into a problem of major concern. Therefore, this study had as the main objective the Polystyrene (PS) toughening using different contents of white vulcanized styrene-butadiene rubber (SBRr) waste produced in the shoe industry. The mixtures were initially prepared in a co-rotational double screw extruder and, thereafter, the extruded granules were injection molded. Analyzed were the rheological, mechanical, thermomechanical properties and morphology of the produced blends. The rheological results showed a viscosity increase as the SBRr concentration was augmented, leading to a higher stability when compared to pure Polystyrene. Verified was an increase of impact resistance of 189% to the blend that contained 50% of SBR rather than pure Polystyrene. On the other hand, the traction properties, hardness Shore D, thermal deflection temperature (HDT) and Vicat softening temperature of the blends tended to decrease when compared to pure Polystyrene results. However, as this SBR waste is made up of a complex mixture of SBR, filler, processing additions, curing agents and stabilizers, it probably acted in the sense of not causing such a drastic reduction of the properties, even using a high concentration of SBRr waste. The morphologies obtained with the SEM method (Scanning Electronic Microscope) were quite different and typical of immiscible blends. The results show that it is possible to obtain a new material with good properties, valuing a discarded industrial waste and avoiding environment aggression

Toughening of polystyrene using styrene-butadiene rubber (SBRr) waste from the shoe industry

<div><p>Abstract The vulcanized rubber waste from the shoe industry causes environmental damage when it is incinerated or inappropriately discarded, turning this into a problem of major concern. Therefore, this study had as the main objective the Polystyrene (PS) toughening using different contents of white vulcanized styrene-butadiene rubber (SBRr) waste produced in the shoe industry. The mixtures were initially prepared in a co-rotational double screw extruder and, thereafter, the extruded granules were injection molded. Analyzed were the rheological, mechanical, thermomechanical properties and morphology of the produced blends. The rheological results showed a viscosity increase as the SBRr concentration was augmented, leading to a higher stability when compared to pure Polystyrene. Verified was an increase of impact resistance of 189% to the blend that contained 50% of SBR rather than pure Polystyrene. On the other hand, the traction properties, hardness Shore D, thermal deflection temperature (HDT) and Vicat softening temperature of the blends tended to decrease when compared to pure Polystyrene results. However, as this SBR waste is made up of a complex mixture of SBR, filler, processing additions, curing agents and stabilizers, it probably acted in the sense of not causing such a drastic reduction of the properties, even using a high concentration of SBRr waste. The morphologies obtained with the SEM method (Scanning Electronic Microscope) were quite different and typical of immiscible blends. The results show that it is possible to obtain a new material with good properties, valuing a discarded industrial waste and avoiding environment aggression.</p></div

Toughening of polystyrene using styrene-butadiene rubber (SBRr) waste from the shoe industry

<div><p>Abstract The vulcanized rubber waste from the shoe industry causes environmental damage when it is incinerated or inappropriately discarded, turning this into a problem of major concern. Therefore, this study had as the main objective the Polystyrene (PS) toughening using different contents of white vulcanized styrene-butadiene rubber (SBRr) waste produced in the shoe industry. The mixtures were initially prepared in a co-rotational double screw extruder and, thereafter, the extruded granules were injection molded. Analyzed were the rheological, mechanical, thermomechanical properties and morphology of the produced blends. The rheological results showed a viscosity increase as the SBRr concentration was augmented, leading to a higher stability when compared to pure Polystyrene. Verified was an increase of impact resistance of 189% to the blend that contained 50% of SBR rather than pure Polystyrene. On the other hand, the traction properties, hardness Shore D, thermal deflection temperature (HDT) and Vicat softening temperature of the blends tended to decrease when compared to pure Polystyrene results. However, as this SBR waste is made up of a complex mixture of SBR, filler, processing additions, curing agents and stabilizers, it probably acted in the sense of not causing such a drastic reduction of the properties, even using a high concentration of SBRr waste. The morphologies obtained with the SEM method (Scanning Electronic Microscope) were quite different and typical of immiscible blends. The results show that it is possible to obtain a new material with good properties, valuing a discarded industrial waste and avoiding environment aggression.</p></div

Processing and Properties of PCL/Cotton Linter Compounds

Biodegradable compounds of poly(&#949;-caprolactone) (PCL)/ cotton linter were melting mixed with filling content ranging from 1% to 5% w/w. Cotton linter is an important byproduct of textile industry; in this work it was used in raw state and after acid hydrolysis. According to the results of torque rheometry no decaying of viscosity took place during compounding, evidencing absence of breaking down in molecular weight. The thermal stability increased by 20% as observed in HDT for PCL/cotton nanolinter compounds. Adding cotton linter to PCL didn't change its crystalline character as showed by XRD; however an increase in degree of crystallinity was observed by means of DSC. From mechanical tests in tension was observed an increase in ductility of PCL, and from mechanical tests in flexion an increase in elastic modulus upon addition of cotton linter, whereas impact strength presented lower values for PCL/cotton linter and PCL/cotton nanolinter compounds. SEM images showed that PCL presents plastic fracture and cotton linter has an interlacing fibril structure with high L/D ratio, which are in agreement with matrix/fibril morphology observed for PCL/cotton linter compounds. PCL/cotton linter compounds made in this work cost less than neat PCL matrix and presented improved properties making feasible its commercial use

Performance of Poly(caprolactone) (PCL) as an Impact Modifier for Polystyrene (PS): Effect of Functionalized Compatibilizers with Maleic Anhydride and Glycidyl Methacrylate

In this work, the copolymers ethylene-glycidyl methacrylate (E-GMA), ethylene methyl methacrylate-glycidyl methacrylate (EMA-GMA), and styrene-(ethylene-butylene)-styrene grafted with maleic anhydride (SEBS-g-MA) were used to compatibilize polystyrene (PS)/poly(caprolactone) (PCL) blends. The blends were processed in a co-rotating twin-screw extruder and injection molded. Samples were investigated by torque rheometry, capillary rheometry, impact strength, tensile strength, heat deflection temperature (HDT), dynamic-mechanical thermal analysis (DMTA), thermogravimetry (TG), and scanning electron microscopy (SEM). Torque rheometry indicated that glycidyl methacrylate functional groups and maleic anhydride groups interact with PCL. Capillary rheometry evidenced that at shear rates lower than 10,000 s&minus;1, the PS/PCL/SEBS-g-MA blends presented the highest apparent viscosity among the blends. Such behavior was possibly due to the good interaction between SEBS-g-MA and the PS and PCL phases. Consequently, the properties of impact strength, elongation at break, tensile strength, and elastic modulus were improved by 30%, 109%, 33.8%, and 13.7%, respectively, compared with the non-compatibilized PS/PCL system. There was a reduction in the HDT of all blends compared with neat PS, given the elastomeric characteristics of PCL and compatibilizers. The DMTA results revealed two independent peaks in the blends (one around &minus;53 &deg;C concerning the PCL phase and another at 107 &deg;C related to PS), confirming their immiscibility. The PS/PCL/SEBS-g-MA blends showed higher morphological stability, confirming their good mechanical properties