Composições de polipropileno heterofásico e borracha EPDM com a incorporação de resíduo de polipropileno e artefatos

DepositadaSão descritas composições de polipropileno heterofásico e borracha EPDM com a incorporação de resíduo de PP na proporção entre 40 e 60% em massa de PP resíduo na composição. As composições são obtidas por extrusão e moldadas em artefatos cujas propriedades mecânicas são avaliadas. Por sua propriedades, as composições da invenção são úteis na indústria automobilística, incluindo a fabricação de para-choques automotivos

Chemical treatment of coconut fiber and its composite / Tratamento químico da fibra de coco e seus compósitos

Composites with natural fibers usually present poor adhesion of filler to the matrix, as consequence of the hydrophilic nature of the fiber and hydrophobic nature of the polymer. These composites also display processing limitations due to the low thermal stability of the fiber. In order to reduce these issues, chemical treatments are usually employed. Thus, the present work aims to combine the processes of mercerization and bleaching to evaluate changes in thermal stability, tensile and impact strengths, flow behaviour and morphology of composites based on HDPE/coconut fiber, with treated and untreated fibers. The results showed that the treated fiber showed better thermal stability comparing to untreated one. The composites produced with both fibers showed an increase in elastic modulus and a reduction in the flow behaviour. However, only those obtained with the treated fiber showed an increase in impact strength in relation to neat HDPE, indicating a better interaction between the treated fiber and the HDPE matrix. These results corroborate the images obtained in SEM micrographs

Influence of processing parameters on mechanical and thermal behavior of PLA/PBAT blend

Abstract This study evaluates the influence of processing parameters and reactive extrusion on the mechanical and thermal behavior of PLA/PBAT (70/30, wt.%) blends. The effect of reverse mixing elements (RME) and feed rate (FR) of the extruder were studied using a factorial design of experiments. Further, two types of blends were processed by extrusion molding: with (AD) and without (NAD) additives. The FTIR analysis showed that PLA suffered some degree of degradation, being this process more pronounced for NAD blends. A better interaction between the PLA and PBAT phases occurred for reactive extrusion, inducing an improvement in the impact properties and thermal behavior. The cold crystallization temperature of the NAD blends decreased when two RME was used. Both RME and FR parameters affected the elastic modulus of NAD blends, while only FR affected the elastic modulus of AD blends

Use of Post-Consumer Plastics in the Production of Wood-Plastic Composites for Building Components: A Systematic Review

This systematic review study adopted the PRISMA methodology to investigate recent research on wood-plastic composites (WPC) utilizing post-consumer plastics in the construction industry. Initially, 3111 articles were selected from academic databases using keywords such as “wood and plastic composites”, “WPC”, “polymer”, “recycled”, “waste”, “construction”, and “sustainability.” After stringent exclusion criteria, 15 relevant studies on plastic waste composites were identified. These studies often employ post-consumer plastics like polypropylene and high-density polyethylene, along with plant-based fillers, aiming to enhance mechanical properties and reduce reliance on virgin materials. Analysis of these studies revealed that the optimal plastic composition in the composites ranged from 40% to 45% wood and from 50% to 60% plastic, with the extrusion process being the most employed for shaping. Specific factors, such as the use of compatibilizers and the particle size of raw materials, were identified as significant influencers on composite strength. These materials exhibited high thermal stability, rendering them suitable for construction applications exposed to high temperatures. The diversity of plastic waste explored in the studies underscores the potential to tailor thermal properties to specific application demands. These composites facilitate closed-loop plastic recycling, enabling their reintegration into the production chain and offering opportunities for lightweight, durable, and high-performance products in the construction industry. However, beyond the factors examined in the studies, a meticulous assessment of the fire resistance, weather resistance, ultraviolet resistance, moisture absorption, dimensional stability, degradation, long-term durability, impact strength, recyclability, and cost-effectiveness of the material is crucial. Thoughtful consideration of these factors is essential to achieving a comprehensive understanding of the potential and limitations of recycled plastic composites in promoting energy efficiency and sustainability in the construction industry

Influence of lubricant oil residual fraction on recycled high density polyethylene properties and plastic packaging reverse logistics proposal

Abstract To recycle post-consumer HDPE contaminated with waste lubricating oils, companies include prior washing and drying in the process. This consumes large amounts of water and energy, generates significant effluent requiring treatment. This study assesses lubricating oil influence on HDPE properties to evaluate the feasibility of its direct mechanical recycling without washing. The current lubricating oil packaging reverse logistics in Rio de Janeiro municipality is also analyzed. HDPE bottle samples were processed with seven oil contents ranging from 1.6-29.4 (wt%). The results indicated the possibility to reprocess the polymer with oily residue not exceeding 3.2%. At higher levels, the external oil lubricating action affects the plastic matrix processing in the extruder and injection, and the recycled material has a burnt oil odor and free oil on the surface. Small residual oil amounts retain the plastic properties comparable to the washed recycled polymer and exhibited benefits associated with the oil plasticizer action. However, oil presence above 7.7% significantly changes the properties and reduces the elasticity and flexural modulus and the plastic matrix crystallinity

Mulheres cuidando de mulheres: um estudo sobre a Casa de Apoio Viva Maria, Porto Alegre, Rio Grande do Sul, Brasil

Este trabalho teve como objetivo obter dados a respeito de mulheres vitimizadas que são atendidas em uma casa abrigo governamental denominada "Casa de Apoio Viva Maria", situada na cidade de Porto Alegre. Analisaram-se informações referentes a 110 mulheres que estiveram albergadas na casa durante os últimos dois anos - janeiro de 1996 a junho de 1998. O perfil da clientela mostrou que as mulheres eram jovens - em média, 29 anos; todas de baixa renda; 12% analfabetas, 21% negras, 80% delas com história de violência doméstica freqüente. Além disso, 18% destas mulheres retornaram à relação com o companheiro violento. Foram efetuadas visitas domiciliares a 34 ex-moradoras, convidando-as a participar de uma série de oficinas de avaliação. Um total de 118 pessoas - mães e crianças - integrou os três encontros de avaliação. Durante estes, os pesquisadores estimularam as participantes a expressar suas opiniões, percepções e sentimentos a respeito da experiência vivida na casa abrigo, assim como seus conceitos no tocante à violência. Finalmente, realizou-se um grupo focal com a equipe técnico-administrativa da casa. As trabalhadoras enfatizaram o quanto esse tipo de trabalho tem sido útil para seu desenvolvimento pessoal e auxiliou a modificar suas vidas

Mulheres cuidando de mulheres: um estudo sobre a Casa de Apoio Viva Maria, Porto Alegre, Rio Grande do Sul, Brasil

Este trabalho teve como objetivo obter dados a respeito de mulheres vitimizadas que são atendidas em uma casa abrigo governamental denominada "Casa de Apoio Viva Maria", situada na cidade de Porto Alegre. Analisaram-se informações referentes a 110 mulheres que estiveram albergadas na casa durante os últimos dois anos - janeiro de 1996 a junho de 1998. O perfil da clientela mostrou que as mulheres eram jovens - em média, 29 anos; todas de baixa renda; 12% analfabetas, 21% negras, 80% delas com história de violência doméstica freqüente. Além disso, 18% destas mulheres retornaram à relação com o companheiro violento. Foram efetuadas visitas domiciliares a 34 ex-moradoras, convidando-as a participar de uma série de oficinas de avaliação. Um total de 118 pessoas - mães e crianças - integrou os três encontros de avaliação. Durante estes, os pesquisadores estimularam as participantes a expressar suas opiniões, percepções e sentimentos a respeito da experiência vivida na casa abrigo, assim como seus conceitos no tocante à violência. Finalmente, realizou-se um grupo focal com a equipe técnico-administrativa da casa. As trabalhadoras enfatizaram o quanto esse tipo de trabalho tem sido útil para seu desenvolvimento pessoal e auxiliou a modificar suas vidas