Porous membranes based on polypropylene-ethylene copolymers. Influence of temperature on extrusion, annealing and uniaxial strain stages
In this study, block and random copolymers of polypropylene–ethylene are selected to prepare porous membranes through the melt extrusion-annealing-uniaxial stretching technique (MEAUS), at a constant draw ratio. In some cases, these copolymers were blended with a homopolymer grade. The variation of...
| Authors: | , , , , , |
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| Format: | article |
| Publication Date: | 2018 |
| Country: | España |
| Institution: | Universitat Politècnica de Catalunya (UPC) |
| Repository: | UPCommons. Portal del coneixement obert de la UPC |
| Language: | English |
| OAI Identifier: | oai:upcommons.upc.edu:2117/121070 |
| Online Access: | https://hdl.handle.net/2117/121070 https://dx.doi.org/10.3390/polym10080854 |
| Access Level: | Open access |
| Keyword: | Membranes (Technology) Membranes (Technology)--Materials Copolymers Polypropylene Block copolymers Porous membranes Polypropylene-ethylene Extrusion Membranes (Tecnologia) Copolímers de bloc Polipropilè Àrees temàtiques de la UPC::Enginyeria dels materials |
| Summary: | In this study, block and random copolymers of polypropylene–ethylene are selected to prepare porous membranes through the melt extrusion-annealing-uniaxial stretching technique (MEAUS), at a constant draw ratio. In some cases, these copolymers were blended with a homopolymer grade. The variation of temperature in the stages of extrusion, annealing and uniaxial strain was analysed. Several characterisation techniques were employed to study this influence. The crystalline orientation was analysed by polarised infrared spectroscopy (FT-IR), and crystalline features were studied by differential scanning calorimetry (DSC). The thermal stability of the membranes was checked by thermogravimetric analysis (TGA). Tensile tests were performed to ascertain the stiffness and ductility of the produced samples. The results were correlated with the porous morphology, global porosity, and permeability to air. A close relationship was found between crystalline characteristics, porous morphology and the trends registered. An improved pore distribution along the membrane surface was found when copolymers were employed |
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