Urban freight transport is a challenge for Brazilian cities due to the lack of adequate planning for freight flow movement. Public managers also show negligence and a lack of awareness when dealing with urban logistics. Decision-support data on urban freight transport are still scarce, despite being of fundamental value to economic development. With this in mind, this paper presents problems and solutions regarding urban freight transport in Brazilian cities. Data were obtained through a survey conducted in nine cities and analysed by means of descriptive statistics and the successive intervals method. Additionally, a cluster analysis was performed to identify patterns regarding the typical characteristics of each city in order to compare and generalise the perception of retailers regarding problems and solutions at the national level. The results indicate divergent opinions among retailers from different cities, even from cities with similar socioeconomic profiles and urban dynamics. The municipalities which demonstrated the most similarities were (i) Betim and Niteroi, in the Southeast of Brazil; (ii) Palmas and Quixada, in the North and Northeast, respectively; and (iii) Palmas and Caruaru, also in the North and Northeast. The results reinforce the importance of studying the local context and involving stakeholders in the process of planning urban logistics solutions.

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The aim of this work is to evaluate the effect of SEBS content and of thermal treatment on the properties of poly(lactic acid)/styrene‐ethylene butylene‐styrene (PLA/SEBS) bioblends. X‐Ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) results show that the thermal treatment leads to the crystallization of PLA matrix, resulting in the increase of the impact strength. The PLA/SEBS bioblends containing 5 and 10% of SEBS show the highest impact strength before and after the thermal treatment. From the rheological measurements under dynamic‐oscillatory shear flow, it is observed that at low frequencies, PLA and PLA/SEBS bioblends containing 5 and 10% of SEBS exhibit a Newtonian behavior, whereas the bioblends containing 15 and 20% of SEBS present a shear thinning behavior. Cole‐Cole and Han plots show that PLA/SEBS bioblends are immiscible. SEM results show that the PLA/SEBS bioblends are immiscible, and that the bioblends containing 15 and 20% of SEBS present the highest SEBS dispersed phase domains size. The thermal treatment has no effect on the morphology of PLA/SEBS bioblends, but improves the impact strength.

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The aim of this work was to evaluate the effect different polyethylene grafted with acrylic acid (PEgAA) copolymer content on the mechanical and thermal properties and morphology of poly(lactic acid) (PLA) biopolymer. The PLA/PEgAA blends containing 5, 10, 15 and 20% (wt) of PEgAA copolymer were prepared by extrusion followed by injection molding and characterized by Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Dynamic Mechanical Thermal Analysis (DMTA), mechanical properties and Scanning Electron Microscopy (SEM). FTIR analysis indicated that a polyesterification reaction between the hydroxyl groups of PLA and the carboxyl groups of PEgAA may have occurred. DSC and DMTA analyzes indicated that the addition of PEgAA to PLA lead to the decrease in cold crystallization (T cc ) temperature of PLA. The impact strength of PLA was increased with the increase in the PEgAA content up to 15%. The PEgAA domains size increased with the increase in the PEgAA content, indicating a weak interaction between the PLA and PEgAA phases.

In recent years the search for biodegradable polymers has excelled due to environmental issues. Among the biodegradable polymers from renewable sources, the poly (lactic acid) - PLA is one of the most widely used commercially, and several researches are being developed in order to improve their properties and thus increase its commercial applicability. Thus, this work aims to study the effects of incorporating polymer modifier (MBS Copolymer, Biostrength 150 - B150) and organoclay (Brasgel PA) in the properties of PLA. The study was conducted in two stages: with and without clay, and both with the B150. The concentrations used were 90/10 (PLA / modifier) and 3pcr (parts per hundred resin) of organoclay. The results showed that the mechanical properties of tensile and impact PLA significantly improved by using the polymeric modifier, indicating a gain in impact strength without a significant loss in modulus of elasticity.

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