Use of inorganic natural nanotubes and synthetic carbon nanotubes in poly(lactic acid)

Download

index.pdf

Date

2015

Author

Erpek Yeniova, Canan Esma

Metadata

Show full item record

Item Usage Stats

253
views

123
downloads

Poly(lactic acid) (PLA) is one of the most important biodegradable aliphatic polyesters, which has attracted great attention in the recent years owing to its excellent material properties. The main objective of this study was to process and characterize Halloysite nanotube (HNT)/PLA nanocomposites. The constituents were observed to be incompatible when processed by classical melt mixing methods, without HNT pre-treatments or addition of plasticizers which act as compatibilizer. In order to achieve the desired physical properties different mixing methods were tried: Direct melt mixing for 3 minute (DM3), direct melt mixing for 10 minute (DM10), masterbatch melt mixing (MMA), solvent casting followed by melt mixing (SC), suspension addition to melt mixing (SA). In addition, HNT minerals were subjected to different pre-treatments: Purification of HNT (p-HNT), functionalization of HNT by grafting with organo-silane (o-HNT), modification of HNT with quaternary salt (m-HNT), and evacuation pre-treatment (e-HNT) to improve the compatibility between PLA and HNT. Among the pre-treated HNT minerals, only the samples prepared by e-HNT showed nanocomposite formation due to the removal of water layer that had remained between the layers of silicate which might hinder the desired compatibilization. For plasticization of PLA, and to provide compatibilization between PLA and HNT two types of blends were processed: PLA plasticized with poly(ethylene glycol) (PEG), P-PLA, and PLA toughened with elastomeric thermoplastic polyurethane (TPU), T-PLA. Addition of HNT was observed to greatly contribute to the improvement of the elongation at break of T-PLA polymers due to the relatively better compatibilization effect of TPU. The results obtained in this study with the local ESAN HNT were cross checked with a reference imported Nanoclay HNT. Also, the comparison of the properties of HNT based composites with the properties of composites prepared with synthetic carbon nanotube (CNT) was performed. According to results, HNT minerals have no chance to compete with CNT as a filler in PLA matrix unless: The residual water between silica layers are removed or a perfect compatibilizer is used.

Subject Keywords

Nanotubes., Halloysite., Polylactic acid., Carbon nanotubes., Nanostructured materials.

URI

http://etd.lib.metu.edu.tr/upload/12618368/index.pdf
https://hdl.handle.net/11511/24315

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Effects of anodizing parameters on the formation of titanium dioxide nanotube arrays on Ti6Al4V alloy Bölükoğlu, Zeynep Ayça; Karakaya, İshak; Department of Metallurgical and Materials Engineering (2015) Titanium dioxide thin films with nanoporous structures recently gained great interest due to their large surface area and high reactivity properties in their applications. One of the methods used to form titanium dioxide nanostructures is anodizing the surface of titanium and its alloys in F- ion containing electrolytes. Effects of hydrofluoric acid (HF) concentration (0.1 to 0.5 wt.%), anodizing potential (10 to 30 V) and time (30 to 180 minutes) on the titanium dioxide nanotube formation were investigated...
Recycling of Polymer Waste Using Different Techniques Sivri, Seda; Sezgi, Naime Aslı; Dilek Hacıhabiboğlu, Çerağ; Department of Chemical Engineering (2023-1-26) Polylactic acid (PLA) is the most widely known renewable biodegradable polymer due to its mass production, good processability, optical, mechanical, thermal, and barrier properties. Hence, the production rate of PLA increased gradually during the last decade. However, PLA is known to have slow degradation rate in soil and marine environments, leading to significant waste accumulation with widespread usage of the polymer. Thus, recycling of PLA waste will become a significant environmental concern in near fu...
A density functional theory investigation of graphene-based materials Sayın, Ceren Sibel; Toffoli, Hande; Department of Physics (2014) Employability of graphene-based materials in various technological applications in order to exploit its exceptional properties is achieved/improved via their interactions with various atoms, molecules, nanostructures and surfaces. In this thesis, the interaction of cyclohexane and derived molecules, carbon nanotubes and metallic surfaces with both pristine and defected graphene structures are investigated using density functional theory.
Synthesis and characterization of sta incorporated mesoporous materials as catalysts for polyethylene pyrolysis Kelebek, Neriman; Sezgi, Naime Aslı; Department of Chemical Engineering (2016) Pyrolysis of polymers, which is a process for recovery of the waste polymer, has attracted great attention in recent years due to the high amount of plastic waste present in nature.However, degradation rocess requires high amount of external energy to break long chain of chemical bonds in the polymer. For this reason, suitable catalysts with strong acid sites are necessary. High surface area silica structured mesoporous materials with narrow pore size distributions are excellent catalysts for these reaction...
Preparation and surface modification of noble metal nanoparticles with tunable optical properties for SERS applications Kaya, Murat; Volkan, Mürvet; Department of Chemistry (2011) Metal nanostructures exhibit a wide variety of interesting physical and chemical properties, which can be tailored by altering their size, morphology, composition, and environment. Gold and silver nanostructures have received considerable attention for many decades because of their widespread use in applications such as catalysis, photonics, electronics, optoelectronics, information storage, chemical and biological sensing, surface plasmon resonance and surface-enhanced Raman scattering (SERS) detection. Th...

Citation Formats

C. E. Erpek Yeniova, “Use of inorganic natural nanotubes and synthetic carbon nanotubes in poly(lactic acid),” Ph.D. - Doctoral Program, Middle East Technical University, 2015.