Search results for "polyamide"

Using organoclay to promote morphology refinement and co-continuity in high-density polyethylene/polyamide 6 blends – Effect of filler content and po…

2010

We investigate the gradual changes of the microstructure of two blends of high-density polyethylene (HOPE) and polyamide 6 (PA6) at opposite composition filled with increasing amounts of an organo-modified clay. The filler locates preferentially inside the polyamide phase, bringing about radical alterations in the micron-scale arrangement of the polymer phases. When the host polyamide represents the major constituent, a sudden reduction of the average sizes of the polyethylene droplets was observed upon addition of even low amounts of organoclay. A morphology refinement was also noticed at low filler contents when the particles distributes inside the minor phase. In this case, however, keep…

1980

Heat-Resistant Fully Bio-Based Nanocomposite Blends Based on Poly(lactic acid)

2013

Poly(lactic acid) (PLA) is melt mixed with polyamide 11 (PA11) to obtain a heat-resistant fully bio-based blend with PLA as the dominant component. The goal is achieved by adding small amounts of organoclay (OMMT), which is used to manipulate the blend microstructure. The selective positioning of the OMMT inside the PA11 and at the PLA/PA11 interface turns the blend morphology from drop/matrix into co-continuous at high PLA content (70 wt%). The OMMT-rich PA11 framework that interpenetrates the major PLA phase effectively contributes to bear stresses, and the nanocomposite blend keeps its structural integrity up to ≈160 °C, i.e., about 100 °C above the PLA glass transition.

Strukturuntersuchungen von polyamiden aus cyclischen dicarbonsäuren und piperazin durch direkten abbau im massenspektrometer

1977

Polyamide aus 1,2-Cyclobutan-, 1,2-Cyclopentan- und 1,2-Cyclohexandicarbonsaure und Piperazin wurden direkt in der Ionenquelle eines Massenspektrometers pyrolysiert. Die hohe Empfindlichkeit der massenspektrometrischen Methode erlaubt, bei Abbauraten von ca. 1%/min zu pyrolysieren und dadurch selektive thermische Abbaumechanismen neben den Fragmentierungsreaktionen nachzuweisen. Durch thermischen Abbau werden dabei Oligomere mit Piperazinendgruppen sowie gesattigte und ungesattigte Cyclobutan-, -pentan- und -hexanendgruppen gebildet. Polyamides of 1,2-cyclobutane-, 1,2-cyclopentane- and 1,2-cyclohexane-dicarboxylic acid and piperazine were pyrolyzed directly in the ion source of a mass spec…

1982

Silanol-POSS as dispersing agents for carbon nanotubes in polyamide

2017

Silanol polyhedrad oligomeric silsesquiosane terminated with phenyl rings (phPOSS) has been considered as dispersing agent for carbon nanotubes (CNTs) in polyamide (PA) matrix. Two different approaches have been followed for the introduction of the phPOSS molecules: a “classical” approach which involves the introduction of the dispersing agent during the melt mixing, and an “innovative” approach, consisting in the immobilization, either covalent and non-covalent, of phPOSS molecules onto CNTs surface. The properties of PA-based nanocomposites, containing free phPOSS molecules and phPOSS molecules immobilized onto the CNTs outer surface, have been evaluated through rheological, mecha…

Effect of silane coupling treatment on the adhesion between polyamide and epoxy based composites reinforced with carbon fibers

2020

The increasing efforts aimed to design structures with reduced weight and better mechanical performances has led in recent years to a growing use of fiber reinforced polymer materials in several fields such as marine. However, these materials can be composed of chemically very different elements and, hence, may be difficult to joint. This research aims to improve the adhesion between a thermoplastic matrix of polyamide reinforced with short carbon fibers (PA12-CR) and a carbon fiber reinforced epoxy matrix (CFRP). Two different silane coupling agents, (3-Aminopropyl)trimethoxysilane (AM) and (3-Glycidyloxypropyl)trimethoxysilane (EP), were applied, through the spray deposition method, on th…

“Compatibilization” through Elongational Flow Processing of LDPE/PA6 Blends

2018

Polyamide/polyolefin blends have gained attention from the academia and the industry for several years. However, in order to optimize their properties, some drawbacks such as chemical incompatibility must be adequately overcome. This can be done by adding suitable compatibilizers. On the other hand, it is less known that suitable processing techniques may also lead to significant results. In a previous work on a low-density polyethylene/polyamide 6 (LDPE/PA6) blend, we found that the orientation due to elongational flow processing conditions could lead to an unexpected brittle&ndash

Improved carbon nanotubes dispersion through polar dispersant agents in polyamide

2016

The potential enhancement of the nanocomposite properties, with respect to the neat matrix, is strictly related to uniform distribution and dispersion of the nanofillers in the host polymer. In this work, two dispersant agents, particularly a polar wax and a silanol polyhedral oligomeric silsesquioxanes POSS, have been used in order to improve the dispersion of bare and functionalized carbon nanotubes in polyamide matrix. To ensure a good compatibility between matrix and nanofillers, the dispersing agents having specific polarity have been chosen, in order to match that of the matrix. Significant alterations of the mechanical and rheological behaviour due to dispersion action of used additi…

Optimization of two-step techniques engineered for the preparation of polyamide 6 graphene oxide nanocomposites

2019

Abstract Different processing conditions to achieve polyamide 6 (PA6)-graphene oxide (GO) nanocomposites were investigated. GO was pre-dispersed in PA6 by three different solvent-based methods and, further, melt processed to prepare nanocomposites at two different loading levels, namely 2 and 5 wt.%. The evolution of rheological and mechanical properties was analyzed by investigating eventual changes in the microstructure and polymer crystallinity, aiming at providing a detailed processing-structure-properties relationship for these systems.