Abstract:IntroduçãoO polipropileno (PP) é um dos polímeros termoplásticos mais utilizados pela indústria, com uma diversidade de aplicações que incluem embalagens rígidas e flexíveis, descartáveis, tubos e produtos injetados para os mais variados usos. A indústria petroquímica disponibiliza vários tipos de polipropilenos, quais sejam: PP homopolímero, PP copolímero heterofásico e PP copolímero randômico. O PP homopolímero contém apenas o monômero propeno em sua cadeia molecular e, sendo predominantemente de configuraçã… Show more
“…As for the composites with oil, there was a significant reduction in the degree of crystallinity, probably because the oil hindered the formation of crystals, hindering molecular packing and reducing crystallinity. [60] The composites showed three decomposition stages: the first occurs in the room temperature range up to 100 C, attributed to water loss by desorption [61] ; the second loss occurs after 200 C attributed to the decomposition of the MS and oil components [62] ; the third mass loss event was attributed to the decomposition of the BioPE chain and at the same time cellulose, hemicelluloses and lignin.…”
“…The collected data show a clear reduction of T d10% in the addition of MS, this behavior may be related to the fact that MS is a natural filler. [63] The MO addition to BioPE brought the weight loss (T d50% ) to a higher temperature, around 458 C. According to the literature, [60] the use of natural oil in composites can improve thermal stability, thus MO acted as a plasticizing agent and with good thermal stability. The BioPE/PE-g-MA/MS and BioPE/PE-g-AA/MS composites improved T d10% relative to the BioPE/MS composites, suggesting good interaction between the phases.…”
The present investigation aimed to produce ecological composites of biopolyethylene (BioPE) with macaíba shell (MS), using polyethylene‐graft‐maleic anhydride (PE‐g‐MA) and polyethylene‐graft‐acrylic acid (PE‐g‐AA) as compatibilizers, as well as macaíba almond oil as a plasticizing agent. The composites were processed in a co‐rotational twin‐screw extruder and injection molded. The addition of 30% by weight of MS in the BioPE matrix caused a reduction in impact strength and elongation at break, but improved stiffness and heat deflection temperature. The PE‐g‐MA and PE‐g‐AA compatibilizers improved the impact strength of the composites, suggesting increased interactions between the phases. There was an increase in the composites degree of crystallinity, indicating that the MS acted as a nucleating agent. The macaíba oil addition to the composites increased the impact strength, indicating a plasticizing effect. However, the elastic modulus, tensile strength, and degree of crystallinity tended to decrease. In general, the use of PE‐g‐MA compatibilizer was more effective to improve the composites mechanical properties. The reuse of MS is feasible for the production of sustainable composites.
“…As for the composites with oil, there was a significant reduction in the degree of crystallinity, probably because the oil hindered the formation of crystals, hindering molecular packing and reducing crystallinity. [60] The composites showed three decomposition stages: the first occurs in the room temperature range up to 100 C, attributed to water loss by desorption [61] ; the second loss occurs after 200 C attributed to the decomposition of the MS and oil components [62] ; the third mass loss event was attributed to the decomposition of the BioPE chain and at the same time cellulose, hemicelluloses and lignin.…”
“…The collected data show a clear reduction of T d10% in the addition of MS, this behavior may be related to the fact that MS is a natural filler. [63] The MO addition to BioPE brought the weight loss (T d50% ) to a higher temperature, around 458 C. According to the literature, [60] the use of natural oil in composites can improve thermal stability, thus MO acted as a plasticizing agent and with good thermal stability. The BioPE/PE-g-MA/MS and BioPE/PE-g-AA/MS composites improved T d10% relative to the BioPE/MS composites, suggesting good interaction between the phases.…”
The present investigation aimed to produce ecological composites of biopolyethylene (BioPE) with macaíba shell (MS), using polyethylene‐graft‐maleic anhydride (PE‐g‐MA) and polyethylene‐graft‐acrylic acid (PE‐g‐AA) as compatibilizers, as well as macaíba almond oil as a plasticizing agent. The composites were processed in a co‐rotational twin‐screw extruder and injection molded. The addition of 30% by weight of MS in the BioPE matrix caused a reduction in impact strength and elongation at break, but improved stiffness and heat deflection temperature. The PE‐g‐MA and PE‐g‐AA compatibilizers improved the impact strength of the composites, suggesting increased interactions between the phases. There was an increase in the composites degree of crystallinity, indicating that the MS acted as a nucleating agent. The macaíba oil addition to the composites increased the impact strength, indicating a plasticizing effect. However, the elastic modulus, tensile strength, and degree of crystallinity tended to decrease. In general, the use of PE‐g‐MA compatibilizer was more effective to improve the composites mechanical properties. The reuse of MS is feasible for the production of sustainable composites.
“…Regarding the MA degree of grafting, increasing from 0.73% to 2.1% in the PCL-g-MA compatibilizer had little effect on T m , as seen in Table 5. As T m reduction is often associated with the degree of crystal perfection, 45 it is suggested that the PCL/ JWF and PCL/JWF/PCL-g-MA biocomposites presented less perfect and/or smaller crystals in relation to PCL. Similar behavior was reported by Machado et al 46 with polyhydroxybutyrate (PHB)/wood powder composites, indicating that the wood powder in the thermoplastic matrix hinders the crystals formation, therefore non-uniform thickness crystals are formed, decreasing T m .…”
The industrial residue of Jatobá wood flour (JWF) was reused during production of biocomposites based on polycaprolactone (PCL), 50% by weight of JWF was added to PCL matrix. Initially, maleic anhydride-grafted polycaprolactone compatibilizer (PCL-g-MA) was synthesized and characterized using X-ray diffraction (XRD), nuclear magnetic resonance (NMR) and degree of grafting. Afterwards, PCL/JWF and PCL/JWF/PCL-g-MA biocomposites were processed in an internal mixer and injection molded. From the gathered results, increase in torque and reduction in the melt flow index of PCL/JWF biocomposites were verified related to neat PCL. Upon addition of PCL-g-MA to PCL/JWF there was a lubricating effect with reduced torque and increased fluidity. PCL/JWF displayed increased elastic modulus, Shore D hardness, and heat deflection temperature (HDT) around 158.5%, 16% and 24.5%, respectively, related to PCL. Nevertheless, there was decline in tensile strength and impact strength, which were improved in PCL/JWF/PCL-g-MA, suggesting higher interaction among phases, providing greater stress transfer. An interesting finding was the nucleating effect of JWF in PCL matrix, as the increased degree of crystallinity and accelerated crystallization. Morphology of PCL/JWF evidenced several voids, but upon compatibilization with PCL-g-MA, the interfacial adhesion and wetness increased, improving the mechanical properties. JWF reusing presents great potential to produce sustainable biocomposites, reducing the final product costs.
“…The melting temperature of the PLAr was around 172.9 °C, lower when compared to Research, Society and Development, v. 9, n. 12, e13291210767, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i12.10767 the PLA's. As the reduction in the melting temperature is often associated with the crystal's degree of perfection (Nascimento et al, 2013), it is suggested that the lower molar mass of the PLAr has nucleated smaller and less thick crystals, reducing its degree of perfection.…”
Additive manufacturing is growing rapidly in the automotive, medical, and aerospace industries as an option for the manufacturing of products. However, there is a continuous growth in the amount of waste generated by 3D filaments, thus, the reuse practice becomes important, since it brings environmental and economic gains. The present research evaluated the mechanical, thermal, thermomechanical and rheological properties of PLA/PLAr blends containing post-consumption 3D filament. The blends were prepared in a co-rotational twin screw extruder and, subsequently, the extruded granules were injection molded. As the PLAr content in the blends (PLA/PLAr) increased, there was a reduction in viscosity, indicating an improvement in manufacturability. The PLA/PLAr blend (75/25 % wt.) increased the degree of crystallinity compared to neat PLA, indicating that PLAr acted as a nucleating agent. As a consequence, the PLA/PLAr blend (75/25 % wt.) showed performance comparable to neat PLA in thermal stability, elastic modulus, tensile strength, Shore D hardness, impact strength, heat deflection temperature (HDT) and Vicat softening temperature. The reuse of post-consumption 3D filament PLA is feasible for the development of materials with good properties. In addition, value is added to the post-consumption material and there is a contribution to sustainable development.
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