Comportamento reológico do Bio-PE e do PCL na presença do PEgAA e PEgMA

O reômetro de torque é um equipamento que reproduz em escala laboratorial o processamento de polímeros.Neste equipamento, a velocidade de rotação dos rotores, temperatura e tempo de processamento são parâmetrospredeterminados e impostos ao sistema investigado; avalia-se o torque necessário para a fusão, mistura ehomogeneização da amostra. Através do gráfico do torque em função do tempo e do gráfico da temperaturaem função do tempo de processamento, cujos valores estão relacionados com as propriedades reológicas,estrutura e massa molar das amostras, é possível obter informações sobre o comportamento dos polímeros emfluxo, ou seja, durante o processamento. Neste trabalho, foi investigado o efeito do polietileno graftizadocom ácido acrílico (PEgAA) e do polietileno graftizado com anidrido maléico (PEgMA) no biopolietileno(Bio-PE) e no poli(ε-caprolactona) (PCL) por reometria de torque. Foi verificado que o PEgAA e o PEgMApromoveram aumento no torque dos sistemas Bio-PE/PEgAA, Bio-PE/PEgMA, PCL/PEgAA e PCL/PEgMA,possivelmente resultante de interações e/ou reações químicas ocorridas nesses sistemas poliméricos. Espectrosde FTIR evidenciaram possíveis interações e/ou reações químicas entre os grupos funcionais dos polímerosgrafitizados e o Bio-PE e o PCL. Valores de torque mais altos foram observados nos sistemas com parâmetrosde solubilidade (δ) mais próximos, corroborando com os cálculos propostos por Hansen

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

Impact of the natural filler babassu on the processing and properties of PBAT/PHB films

Melt extruded films consisting of polybutyrate adipate terephthalate (PBAT), poly(3-hydroxybutyrate) (PHB) and babassu as a natural and cost-effective filler were studied aiming at the preparation of partly bio-based and biodegradable films. PHB suffers from low thermal stability entailing a narrow processing window. Rheological, thermal and mechanical properties revealed that an effective processing of the PBAT/PHB blends with well-dispersed babassu is possible. Thermal degradation of the composites during processing and the mechanical properties are driven mainly by the polymer composition and less by the filler. However, babassu addition reduces the crystallization rate and facilitates by this the handling of the extruded films prior to solidification. Among the composites investigated, the composites based on 50%PBAT/50%PHB blends combined both, best processing and handling parameters as well as thermal and mechanical material properties. Babassu was found to facilitate PHB processing while maintaining the overall mechanical properties and giving access to ecologically friendly, cost-effective composite materials