Braskem (Brazil)

esfera ambiental.

Abstract Society’s perception of an environmental impact often turns it into the drive to measure, remediate and ultimately solve the perceived problem. In some cases, this situation is noticeable even before scientists can properly establish the cause-effect pathway, for example, plastic debris effect on the oceans. This work strives to understand how public opinion deals with this transitory gap of knowledge and how to measure society’s viewpoint through marine litter. A Life Cycle Assessment was addressed comparing reusable and single-use drinking straws, from which a “society’s perception based” characterization factor for mismanaged polymers at end of life was proposed. Results showed that the factor may reach up to 1 order of magnitude higher than the characterization factors of producing the polymer and may indicate that decisions with no data to support can lead to rebound effects.

ABSTRACT 1,3-butadiene (1,3-BD) is a building block produced mainly as a byproduct of the ethylene steam cracking process. However, due to the growing interest in sustainable technologies, there is also growing interest in manufacturing 1,3-BD from ethanol. For this reason, taking into account that the ethanol-derived 1,3-BD can contain oxygenated contaminants that are difficult to remove, the present manuscript investigates for the first time how the presence of low concentrations of some oxygenates (acetaldehyde, crotonaldehyde, 3-hydroxybutyraldehyde, acetone, water, ethanol, 1,3-butanodiol, 3-buten2-ol, crotyl alcohol, and 1-butanol) in the 1,3-BD monomer can affect polymerization reactions performed with the neodymium versatate catalyst and modify the characteristics of the obtained polybutadiene products. It is shown that the presence of oxygenated compounds can cause inhibitory effects on the course of the polymerization and modify the molar mass distributions and flow properties of the final products, although all analyzed samples presented the characteristic high-cis character of polybutadienes produced with the neodymium versatate catalyst.

In this work, silica capsules containing bromothymol blue (BTB) were synthesized by a modified Stober sol–gel method. These silica capsules were dispersed into a high-density polyethylene (HDPE)/ethylene-vinyl acetate (EVA) polymeric matrix and then applied in milk spoilage detection tests. The effect of the KOH/BTB molar ratio used in the sol–gel synthesis on the structural, textural, and morphological characteristics of the resulting silica capsules was also investigated. Field emission gun scanning electron microscopy images of the silica capsules showed particles with spherical morphology and size ranging from 0.1 to 1 µm. All silica capsules presented a very low porosity and an encapsulated BTB content in the range of 12–37 µmol g−1. The increase of the KOH/BTB molar ratio resulted in an increase in the relative amount of six-fold siloxane rings and a decrease in the BET surface area of the silica capsules. Spoilage kinetics of milk at room and fridge temperature were much different, as evidenced by pH milk measurements. The milk storage temperature and the KOH content in the silica capsules affected the intensity and rate of blends color change. Blends (HDPE/EVA/silica capsules) with lower KOH content in the capsules showed faster kinetics and higher intensities of color change during the milk spoilage at both tested temperatures. These results showed the potential of the HDPE/EVA/silica capsules as a base material to a sensor packaging, which allows the verification of the milk quality by the end-users.

Abstract In this work, three polypropylene impact copolymers (ICPs) with different chemical compositions are characterized using gel permeation chromatography (GPC) with triple detection: infrared (IR), viscometer (VIS) and multi angle light scattering (MALS), crystallization analysis fractionation (CRYSTAF), thermal gradient interaction chromatography (TGIC), nuclear magnetic resonance (13C‐NMR) and atomic force microscopy (AFM). The average rubber composition is determined and correlated with the ICP morphology and final mechanical properties. GPC‐IR is used to analyze the ethylene content and distribution along the molecular weight distribution (MWD). The amorphous phase composition distribution is analyzed as a function of temperature by TGIC. The microstructure and morphology of ICP amorphous phase are studied in detail by 13C‐NMR, GPC 3D, TGIC, SEM and AFM allowing to differentiate the samples.

Commercial Poly(vinyl chloride) (PVC) compounds are based on the combination of the polymer and additives that gives the formulation necessary for the end‐use. In medical‐device applications, PVC may be treated by gamma irradiation in sterilization process. As a consequence of ionization during irradiation, PVC chains undergo simultaneously crosslinking and scission effects. Therefore, it is necessary the study of new additives with radiolytic stabilization characteristics. In this study, the vegetable oil extracted from coffee grounds (OCG) was incorporated in PVC resin as an additive to produce PVC films and PVC test specimens. The viscosity measurements showed that OCG is a promising radioprotection at 0.5 wt% concentration. The results of mechanical and thermal properties are also discussed. The aim of this study is to show that it is possible to develop a formulation for processing PVC with radiation resistance and, at the same time, friendly to the environment due to recycle the wastes from coffee industry.