Preparation and thermomechanical characterization of metallocene linear low‐density polyethylene/carbon nanotube nanocomposites

Abstract

Nanocomposites, based on a metallocene linear low‐density polyethylene matrix (mLLDPE), reinforced with multiwalled carbon nanotubes (CNTs), at various CNT loadings, have been prepared and studied by scanning electron microscopy, differential scanning calorimetry, dynamic mechanical analysis, tensile‐electrical testing, and Raman spectroscopy. The melt‐mixing procedure has been applied to prepare the nanocomposites, whereas the polyethylene matrix type (mLLDPE) employed was proved to be decisive in producing nanocomposites with improved thermomechanical/electrical properties, due to a good quality dispersion of the CNTs into the specific bulk matrix. Moreover, the electrical conductivity obtained at a specific CNT loading was analyzed by a model relating the electrical resistance of the CNT/nanocomposites with the effective length of CNTs, and the thickness of the interphase between matrix and CNTs. These quantities are parameters which participate in the tunnel effect. The simulated parameter values were in accordance with the results of the micromechanics modeling. POLYM. COMPOS., 40:E1263–E1273, 2019. © 2018 Society of Plastics Engineers

Comparing the rheological and reinforcing effects of graphene oxide on glassy and semicrystalline polymers

“…In the mLLDPE materials, the initial linear region is followed by a strain hardening response until fracture, at high strain values for both matrix and its nanocomposite. A double yield stress is clearly shown in mLLDPE, and the same effect was reported in a previous work . The first yield point can be related with the onset of temporary deformation, while the second one is associated with the onset of permanent plastic strain and the necking effect.…”

“…It can be postulated that the reinforcing effect of GO is superior compared to the corresponding effect of CNTs on similar polymeric matrices . As far as mLLDPE is concerned, it has been previously reported a 27% increment for 2 wt% CNTs , while in the present work, an enhancement of 25.3% is obtained at 1 wt%.…”

“…Following Table , the change of heat capacity Δ C p at the glass transition temperature, is found to be slightly reduced with GO for PLA and mLLDPE, exhibiting only a slight increment in PS/1%GO. In our previous work , a Δ C p increment for mLLDPE/CNT nanocomposites has been detected. This finding revealed that more polymeric chains participate in the glass transition, providing an evidence of mLLDPE‐CNTs interaction .…”

Sıcak Plaka Kaynak Yöntemi ile Birleştirilmiş Benzer ve Benzer Olmayan Alçak Yoğunluklu Polietilen (AYPE) Bağlantıların Mekanik Özelliklerinin Karşılaştırmalı Olarak Araştırılması

“…Polietilenler ise sağlamlık, esneklik, yüksek darbe dayanımı ve uygun kimyasal direnç özellikleri ile dikkati çeken en yaygın kullanım alanına sahip poliolefin termoplastiklerdendir [4,5]. Aynı zamanda düşük maliyetli olan bu polimerler, yoğunluk ve sonucundaki özellik değişimleri nedeniyle düşük yoğunluklu polietilen, doğrusal düşük yoğunluklu polietilen ve yüksek yoğunluklu polietilen şeklinde üretilebilmekte ve sınıflandırılmaktadırlar [6,7].…”

Μελέτη Μηχανικών Και Ηλεκτρικών Ιδιοτήτων Νανοσύνθετων Υλικών Για Χρήση Ως Αισθητήρες Παραμόρφωσης Και Φθοράς

“…Όπως έχει αναφερθεί, το ποσοστό κρυσταλλικότητας μπορεί να επηρεάσει το κατώφλι διαφυγής και εν γένει τις ηλεκτρικές ιδιότητες ενός νανοσύνθετου υλικού. Όμως, σύμφωνα με μετρήσεις που έγιναν, προέκυψε ότι όλα τα θερμοπλαστικά δοκίμια που εξετάζονται εδώ έχουν κρυσταλλικότητα που κυμαίνεται μεταξύ 19% και 20% για όλα τα ποσοστά εγκλείσματος καθώς και για τη μήτρα(Charitos 2018). Αντιθέτως, τα ελαστομερή είναι άμορφα.…”