Abstract
Nanocomposites of isotactic polypropylene with 1–5 wt.% of fibrillated PTFE (PP/T) were prepared, and their crystallization during cooling under elevated pressure, in a wide pressure range, up to 300 MPa, as well as the resulting structure, were examined. The crystallization peak temperatures of PP/T, especially with 3 and 5 wt.% of PTFE, exceeded by up to 13 °C those of neat PP. Moreover, a fine-grain structure was formed in PP/T in the entire pressure range, which proved the ability of the fibrillated PTFE to nucleate crystallization of PP in the γ-form under elevated pressure. This also resulted in a higher crystallinity level developed in the γ-domain, before the temperature range of the α-domain was reached during cooling. Hence, the γ-content increased in comparison to that in neat PP, under the pressure up to 200 MPa, especially under 50–100 MPa.
Highlights
All-polymer composites, including self-reinforced composites, are an interesting group of materials
Our study focused on nonisothermal crystallization of isotactic polypropylene (iPP) with fibrillated PTFE during cooling, in a broad pressure range, up to 300 MPa
Nonisothermal crystallization of the polypropylene with 1–5 wt.% of fibrillated PTFE (PP/T) during cooling in a broad pressure range, up to 300 MPa, and the structure formed during the crystallization, were studied
Summary
All-polymer composites, including self-reinforced composites, are an interesting group of materials The advantages of these materials include relatively low weight; easy recycling ability, e.g., reprocessing by remelting; and the possibility of tuning adhesion between the components [1,2]. Such composites can be obtained by filling polymers with ready-made fibers or by the formation of fibers in a matrix, in situ during processing [2]. Poly(tetrafluoroethylene) (PTFE) nanofibrils were formed during the shearing of PTFE powder particles with reduced entanglement density during compounding with melts of other polymers, including isotactic polypropylene (iPP), high density polyethylene (HDPE), low density polyethylene, poly(oxymethylene), and atactic polystyrene [3,4,5,7]. It is worth mentioning that PTFE particles strongly nucleated the crystallization of iPP [12]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
