Deformation and failure of sugarcane bagasse reinforced PP

Polypropylene composites were prepared from sugarcane bagasse fibers by extrusion and injection molding. Wood flour was used as reference filler in the study. The fiber content of the composites changed between 0 and 30 wt% in 5 wt% steps. Maleated polypropylene was used as coupling agent to improve interfacial adhesion. Mechanical properties were characterized by tensile and fracture testing, while local deformation processes were followed by acoustic emission and instrumented impact testing, as well as by the analysis of scanning electron micrographs. The results showed that sugarcane bagasse fibers reinforce polypropylene similarly to other natural fibers. They increases stiffness, but decrease tensile yield stress, tensile strength and deformability. Increased interfacial adhesion leads to the considerable improvement of reinforcement. Bagasse fiber and wood flour filled composites have very similar properties. The impact resistance of the composites increased in the presence of both fibers compared to the neat matrix. Debonding is the dominating process in the absence of the coupling agent, while mainly fiber fracture occurs in its presence. Increased plastic deformation after debonding results in slightly improved impact resistance

DEFORMATION AND FAILURE BEHAVIOUR OF SUGARCANE BAGASSE REINFORCED PP

Polypropylene composites were prepared from sugarcane bagasse fibers by extrusion and injection molding. Wood flour was used as reference filler in the study. The fiber content of the composites changed between 0 and 30 wt% in 5 wt% steps. A maleated polypropylene was used as coupling agent to improve interfacial adhesion. Mechanical properties were characterized by tensile and fracture testing, while local deformation processes were followed by acoustic emission and instrumented impact testing as well as by the analysis of scanning electron micrographs. The results showed that sugarcane bagasse fibers reinforce polypropylene similarly to other natural fibers. They increases stiffness, but decreases tensile yield stress, tensile strength and deformability. Increased interfacial adhesion leads to the considerable improvement of reinforcement. Bagasse fiber and wood flour filled composites have very similar properties. The impact resistance of the composites increased in the presence of both fibers compared to the neat matrix. Debonding is the dominating process in the absence of the coupling agent, while mainly fiber fracture occurs in its presence. Increased plastic deformation after debonding results in slightly improved impact resistance

Alkali treatment of lignocellulosic fibers extracted from sugarcane bagasse: Composition, structure, properties

This work reported the study on the effect of alkali treatment using NaOH solutions of different concentration (0-40 wt.%) of sugarcane bagasse fibers on their composition, structure and properties. The results evidenced that treatment modifies the composition, structure and properties of the fibers. The content of hemicellulose and lignin reduce, while cellulose content turns through a maximum as a function of NaOH concentration. A small change in crystallinity was identified and microfibril angle (MFA) remained constant thus structural effects and especially MFA were not the main reasons for altering the properties. The stiffness of the fibers shows a slight maximum at around 2-4 wt.% NaOH content, while a much more pronounced strength found at around 5-8 wt.%. Direct correlation between structure and mechanical properties was not found, indicating that composition is more essential in the determination of properties than structure. The optimum concentration of the treating solution is around 5 wt% NaOH content, if the time of treatment is fixed at 1 hour

Alkali treatment of lignocellulosic fibers extracted from sugarcane bagasse: Composition, structure, properties

Lignocellulosic fibers extracted from sugarcane bagasse were treated with NaOH solutions of different concentration (0-40 wt%) to study the effect of alkali treatment on the composition, structure and properties of the fibers. Composition was determined by the van Soest method, structure was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), while mechanical properties by tensile testing. Hemicellulose and lignin content decrease, while cellulose content goes through a maximum as a function of alkali concentration. Crystallinity changes only slightly and microfibril angle (MFA) remains constant thus structural effects and especially MFA are not the primary reasons for changing properties. The Youngs modulus of the fibers shows a slight maximum at around 2-4 wt% NaOH content, while tensile strength goes through a much more pronounced one at around 5-8 wt%. Direct correlation between structure and mechanical properties was not found indicating that composition is more important in the determination of properties than structure. Regression analysis proved that the combination of several compositional variables determines mechanical properties in a non-linear manner. The improvement in fiber properties was explained with the dissolution of weak amorphous fractions and the relative increase of cellulose content

Deformation and failure of sugarcane bagasse reinforced PP

Polypropylene composites were prepared from sugarcane bagasse fibers by extrusion and injection molding. Wood flour was used as reference filler in the study. The fiber content of the composites changed between 0 and 30 wt% in 5 wt% steps. Maleated polypropylene was used as coupling agent to improve interfacial adhesion. Mechanical properties were characterized by tensile and fracture testing, while local deformation processes were followed by acoustic emission and instrumented impact testing, as well as by the analysis of scanning electron micrographs. The results showed that sugarcane bagasse fibers reinforce polypropylene similarly to other natural fibers. They increases stiffness, but decrease tensile yield stress, tensile strength and deformability. Increased interfacial adhesion leads to the considerable improvement of reinforcement. Bagasse fiber and wood flour filled composites have very similar properties. The impact resistance of the composites increased in the presence of both fibers compared to the neat matrix. Debonding is the dominating process in the absence of the coupling agent, while mainly fiber fracture occurs in its presence. Increased plastic deformation after debonding results in slightly improved impact resistance

Effectiveness of the Combination of Rituximab and Standard Chemotherapeutic Regimens in Previously Untreated Patients with Chronic Lymphocytic Leukaemia in Real-Life

Chronic lymphocytic leukemia (CLL) is one of the most common haematological malignancies exhibiting remarkable heterogeneity in clinical course. Rituximab added to standard chemotherapy has been proven to increase response rate and eventually survival among previously untreated CLL patients. CILI was an open-label, non-randomized, single arm, multicentric, observational study aimed to collect real-life effectiveness data for rituximab used according to the current label in combination with standard chemotherapy in previously untreated CLL patients. Overall response rates (ORR) in the entire study population as well as in various subgroups were estimated. Adverse events were recorded during the entire course of the study. A total number of 150 patients were enrolled by 15 Hungarian study sites. Out of these, 82 patients received 6 cycles of rituximab containing treatment. Overall response rates of 88.24% (CI95%: 81.6-93.12%) and 94.59% (CI95%: 86.73-98.51%) were recorded in the intent-to-treat (ITT) and per-protocol (PP) populations, respectively. In both study populations, somewhat higher ORR was observed in patients aged ≥65 years. Subgroups defined according to either chromosomal aberrations (presence of 11q and 17p deletions) showed apparently high ORRs, though these rates were most probably biased by low patient numbers. 144 adverse events were reported during the study, of which 15 AEs were considered to be related to the administration of rituximab. Analyses of the efficacy variables have revealed comparable results to those previously reported by controlled clinical trials