High‐performance binary blends between poly(ether imide) (PEI) and flame‐retardant poly(butylene terephthalate) (PBT) are modified with 5, 10, and 15 wt% of poly(tetrafluoroethylene) (PTFE) using a two‐step melt‐processing method. Morphology study reveals that PTFE does not interfere with PEI and PBT interfacial interaction during blends fabrication, and the dual‐phase inversion observed for binary PEI/PBT blends in previous works remains the same. Thermal degradation and fire resistance analyses show that charring layer formation is the major flame protection process and that PTFE enhances charring production for ternary blends. According to UL94 horizontal burning test, all blends are categorized as slow‐burning materials. Bomb calorimetry and thermal gravimetric analyses reveal that there is an interaction between PTFE with PEI and PBT phases, as well as with their degradation products. This phenomenon is explained by X‐ray photoelectron spectroscopy analysis, and it is attributable to Sb‐F species which enhances the formation of an intumescent layer.
The annual worldwide production of coffee exceeds 10 million tons, and more than 90% of this production is waste, including the husk. On the other hand, plastic consumption increases every year, and sustainable alternatives are necessary to decrease it. This work arises to solve these two problems, and seeks to produce products at an industrial level from polyethylene/coffee husk eco-composites. Both Low Density Polyethylene and High Density Polyethylene were used, and the amounts of coffee husk added as filler were 20 and 40 wt%. The composites were characterized by different morphological, thermal and mechanical techniques. Scanning Electron Microscopy images showed husk particles embedded in the polymer matrix, but with some gaps between the polymer and the filler, because no compatibilizer agent was used. The addition of large amounts of natural filler negatively affected the tensile strength and elongation at break, but increases eco-composites crystallinity, and hence, their Young modulus and hardness. The industrial applicability of the eco-composites was verified through the production of five different consumer products by extrusion and injection processes, using mixtures with 40 wt% coffee husks. All products were obtained without significant defects. If only 3.25 wt% of the polyethylene products produced each year in Colombia did so with the eco-composites developed in this work, all the coffee husk produced in the country would be used, and the emission of about 5.390 million m3 of greenhouse gases would be avoided.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.