Role of Carboxylic Acid-Functionalized MWCNTs in Potentially Biodegradable Poly(Amide–Imide) Nanocomposites Based on N,N′-(Pyromellitoyl)-bis-S-valine: Preparation,Thermal and Morphological Properties

A simple solution-blending process was used to efficiently disperse of carboxyl-modified multiwalled carbon nanotubes into a potentially biodegradable poly(amide–imide) to obtain poly(amide–imide)/carboxyl-modified multiwalled carbon nanotubes bionanocomposites. Carboxyl-modified multiwalled carbon nanotubes were utilized to better dispersion of multiwalled carbon nanotubes into the polymer matrix. The poly(amide–imide)/carboxyl-modified multiwalled carbon nanotube bionanocomposites were prepared with different carboxyl-modified multiwalled carbon nanotube contents (5–15 wt%). The resulting bionanocomposites are characterized by several techniques, powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy analysis, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Adding carboxyl-modified multiwalled carbon nanotube into polymer matrix significantly increased the thermal stability of bionanocomposites due to the increased interfacial interaction between the poly(amide–imide) matrix and carboxyl-modified multiwalled carbon nanotube.     

Sono-assisted Synthesis of MgAl-layered Double Hydroxide Nanosheet/multiwalled Carbon Nanotube Filler for the Fabricating of L-isoleucine Amino Acid Based Polymer Nanocomposites

Hybrid of acid functionalized multiwalled carbon nanotubes and layered double hydroxides were prepared by coprecipitation reaction of the Al(NO₃)_3·9H₂O, Mg(NO₃)_2·6H₂O, and acid functionalized multiwalled carbon nanotubes under ultrasonic irradiation. An optically active amino acid containing poly(amide-imide) was synthesized by the direct polycondensation reaction of the N,N′-(pyromellitoyl)-bis-L-isoleucine diacid and diamine using molten tetra-n-butylammonium bromide. These three-dimensional nanofillers were used as reinforcing agent to enhance the performance of chiral poly(amide-imide). The structure and morphology of the hybrid materials were confirmed by Fourier transformed infrared spectroscopy, X-ray diffraction, field emission and transmission electron microscopy, and thermogravimetry analysis techniques.     

Synthesis of Bio-Based Polyamide/Acid-Functionalized Multiwalled Carbon Nanotube Nanocomposites Using Vanillin

Synthesis of bio-based polyamide/acid-functionalized multiwalled carbon nanotube nanocomposites (PA/FCNT NCs) is reported in this investigation. New aliphatic–aromatic bio-based polyamide (PA) was synthesized through direct polycondensation reaction between bio-based diacid derived from a renewable resource; vanillin and diamine containing ether linkages. To obtain a homogeneous dispersion of multiwalled carbon nanotubes (MWCNTs) in the PA matrix, acid-functionalized MWCNTs (FCNTs) were used and PA nanocomposites with three different FCNT contents (1, 5 and 7?wt%) were prepared. The resulting NCs were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and thermogravimetric analysis (TGA).     

In Situ Polymerized Poly(Amide Imide)/Multiwalled Carbon Nanotube Composite: Structural,Mechanical, and Electrical Studies

Poly(amide imide)/multiwalled carbon nanotube composites were in situ polymerized through Yamazaki–Higashi phosphorylation method, and the carboxylated multiwalled carbon nanotubes are added in the post-reaction stage. The good dispersion of multiwalled carbon nanotubes in the poly(amide imide) matrix was achieved even at 20?wt% nanotube loading. The electrical conductivity reached 33?S?m^?1; meanwhile, the tensile strength and Young’s modulus were 106MPa and 2.52?GPa, respectively. These excellent properties were contributed to the good dispersion of nanotubes and strong multiwalled carbon nanotubes–poly(amide imide) interfacial adhesions. We also demonstrate that the incorporation of multiwalled carbon nanotubes depressed the crystallization characteristics of poly(amide imide) but improve its thermal stability.     

Morphological and Thermal Properties of Poly(amide-imide)/ZnO Nanocomposites Derived from 4,4′-methylenebis(3-chloro-2,6-diethyl trimellitimidobenzene) and 3,5-diamino-N-(4-hydroxyphenyl)benzamide

A new nanostructure poly(amide-imide) (PAI) was prepared from the polymerization of 4,4′-methylenebis(3-chloro-2,6-diethyl trimellitimidobenzene) as a diacid with 3,5-diamino-N-(4-hydroxyphenyl)benzamide using triphenyl phosphite as a condensing agent and tetra-n-butylammonium bromide as a green media. The synthesized polymer was used to prepare PAI/ZnO nanocomposites (PZNC)s using nano-ZnO surface-coupled by N-trimellitylimido-L-alanine diacid as a coupling agent through ultrasonic process. The resulting PZNCs were also characterized by FT-IR, powder X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The TEM and FE-SEM results showed a good dispersion of nanoscale inorganic particles in the polymer matrix.     

Effects of thermal imidization on mechanical properties of poly(amide‐co‐imide)/multiwalled carbon nanotube composite films

In this study, experimental and numerical studies were performed to investigate the relationship among the functionalization method, weight fraction of MWCNTs, thermal imidization cycle, and mechanical properties of various PAI/MWCNT composite films. Poly(amide‐co‐imide)/multiwalled carbon nanotube composite films were prepared by solution mixing and film casting. The effects of chemical functionalization and weight fraction of multiwalled carbon nanotubes on thermal imidization and mechanical properties were investigated through experimental and numerical studies. The time needed to achieve sufficient thermal imidization was reduced with increasing multiwalled carbon nanotube content when compared with that of a pure poly(amide‐co‐imide) film because multiwalled carbon nanotubes have a higher thermal conductivity than pure poly(amide‐co‐imide) resin. Mechanical properties of pure poly(amide‐co‐imide) and poly(amide‐co‐imide)/multiwalled carbon nanotube composite films were increased with increasing imidization time and were improved significantly in the case of the composite film filled with hydrogen peroxide treated multiwalled carbon nanotubes. Both the tensile strength and strain to failure of the multiwalled carbon nanotube filled poly(amide‐co‐imide) film were increased substantially because multiwalled carbon nanotube dispersion was improved and covalent bonding was formed between multiwalled carbon nanotubes and poly(amide‐co‐imide) molecules. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Preparation and Characterization of Polyvinylpyrrolidone-functionalized Multiwalled Carbon Nanotube (PVP/f-MWNT) Nanocomposites

Polyvinylpyrrolidone/hydroxyl-functionalized multiwalled carbon nanotube and sulfonyl-functionalized multiwalled carbon nanotube nanocomposites were prepared in aqueous media. The structure, morphology, and thermal characterization of the prepared nanocomposites were done by Fourier transform infrared, scanning electron microscopy, thermogravimetric analysis, and differential scanning calorimetry techniques. The polyvinylpyrrolidone/hydroxyl-functionalized multiwalled carbon nanotube and polyvinylpyrrolidone/sulfonyl-functionalized multiwalled carbon nanotube nanocomposites improved the thermal properties of polyvinylpyrrolidone. According to the differential scanning calorimetry analysis, the glass transition temperature of 101.6 and 84.6°C is observed for the polyvinylpyrrolidone/hydroxyl-functionalized multiwalled carbon nanotube (5% w/w) and polyvinylpyrrolidone/sulfonyl-functionalized multiwalled carbon nanotube (5% w/w) nanocomposites, respectively. The energy-dispersive X-ray spectroscopy image of polyvinylpyrrolidone/sulfonyl-functionalized multiwalled carbon nanotube (5% w/w) nanocomposite showed a homogenous distribution of sulfonyl-functionalized multiwalled carbon nanotube in the polyvinylpyrrolidone matrix.     

Synthesis and Characterization of New Poly(ether-amide-imide)/Amino-Functionalized Fe3O4 Nanocomposites

New poly(amide-imide)/amino functionalized Fe₃O₄ nanocomposites were successfully fabricated through solution intercalation technique. A poly(amide-imide) derived from an imide-containing diacid and ether linkage diamine was synthesized and characterized. Aiming to have better compatibility, the hydrophilic nature of Fe₃O₄@SiO₂ was changed into organophilic using N-[3-(trimethoxysilyl)propyl]ethylenediamine. The amino-functionalized Fe₃O₄ showed well dispersion in the poly(amide-imide) matrix. Thermal gravimetric analysis results indicated that char yields of the nanocomposites were improved. Microscale combustion calorimetry results showed that poly(amide-imide) had good flame retardancy and amino-functionalized Fe₃O₄ has further improved this property of poly(amide-imide).     

Modification of pristine multiwalled carbon nanotube by grafting with poly(methyl methacrylate) using benzoyl peroxide initiator

Multiwalled carbon nanotube was successfully grafted with poly(methyl methacrylate) by free radical mechanism using benzoyl peroxide initiator. The reaction was carried out in situ, where the initiator and methyl methacrylate monomer generated the polymer‐free radical that was subsequently grafted to the surface of the pristine multiwalled carbon nanotube. The multiwalled carbon nanotube grafted poly(methyl methacrylate) (MWCNT‐g‐PMMA) were characterized using Fourier transform infrared, differential scanning calorimetry, thermogravimetric analysis, ¹³ C‐solid NMR spectroscopy, X‐ray photoelectron spectroscopy, and scan electron microscopy. From the result of the characterizations, the grafting of poly(methyl methacrylate) on to multiwalled carbon nanotube was confirmed, and a percentage grafting of 41.51% weight was achieved under optimized conditions with respect to the temperature and the amount of the initiator. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43270.     

Fabrication and Characterization of High-Performance Diglycidyl Ether of Bisphenol-A/Tetrabromobisphenol-A Blend Reinforced with Multiwalled Carbon Nanotube Composite

The nanocomposite of diglycidyl ether of bisphenol-A and diglycidyl ether of bisphenol-A/tetrabromobisphenol-A blend with purified multiwalled carbon nanotube and acid-functional multiwalled carbon nanotube were processed by solution route. According to field emission scanning electron microscope, diglycidyl ether of bisphenol-A/purified multiwalled carbon nanotube depicted poor dispersion and aggregated morphology, however, diglycidyl ether of bisphenol-A/acid-functionalized multiwalled carbon nanotube revealed better dispersion in matrix. The diglycidyl ether of bisphenol-A/tetrabromobisphenol-A/purified multiwalled carbon nanotube had higher thermal stability as T₀ of 369°C and T_max of 569°C were observed. Nonflammability of diglycidyl ether of bisphenol-A/tetrabromobisphenol-A blend-based material was 44%, i.e., higher than diglycidyl ether of bisphenol-A/purified multiwalled carbon nanotube series. Diglycidyl ether of bisphenol-A/tetrabromobisphenol-A/purified multiwalled carbon nanotube 0.1 had crystalline morphology with diffractions at 12.77° and 26.8°. The diglycidyl ether of bisphenol-A/tetrabromobisphenol-A/multiwalled carbon nanotube nanocomposite revealed electromagnetic interference shielding effectiveness of ～12.1?dB, i.e., desired for aerospace applications.     

Improvement of the Interactions between Modified ZrO2 and Poly(amide-imide) Matrix by Using Unique Biosafe Diacid as a Monomer and Coupling Agent

This research explores the synthesis of a high-performance poly(amide-imide) (PAI) from the polycondensation reaction of N-trimellitylimido-L-leucine as a bioactive diacid with 4,4′-diaminediphenylsulphone using combination of triphenyl phosphite and tetra-n-butylammonium bromide as a condensing agent. ZrO₂ nanoparticle (NP) was used as a filler for the formation of PAI nanocomposites (NC)s. For a unique dispersion of NPs in the PAI matrix, the surface of ZrO₂-NPs was modified with bioactive N-trimellitylimido-L-leucine using ultrasonic technique. The obtained polymer and modified ZrO₂-NPs were used to produce PAI/ZrO₂ NCs under ultrasonic irradiation. The obtained NCs were characterized by different methods.     

Novel chiral poly(amide-imide)/surface modified SiO2 nanocomposites based on N-trimellitylimido-l-methionine: Synthesis and a morphological study

In the present investigation, novel poly(amide-imide) (PAI)/SiO₂ nanocomposites (NCs) containing l-methionine moiety in the main chain were prepared via a simple and fast ultrasonic irradiation process. PAI was synthesized by direct poly condensation reaction of N-trimellitylimido-l-methionine with 4,4′-diamino diphenylether in molten tetra-n-butyl ammonium bromide/triphenyl phosphite as a green condensing agent. Due to the high surface energy and tendency for agglomeration, the surface of SiO₂ NPs was modified with chiral diacid. The obtained NCs were characterized by Fourier transform-infrared (FT-IR) spectroscopy, thermogravimetry analysis, X-ray powder diffraction, field emission-scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The FT-IR spectroscopy indicated that the chiral diacid as the coupling agent was attached on the surface of SiO₂ NPs. FE-SEM, and TEM images showed that SiO₂ NPs were dispersed rather homogeneously in the PAI matrix.     

Nonisothermal crystallization kinetic study and thermal stability of multiwalled carbon nanotube reinforced poly(phenylene sulfide) composites

The aim of this work is obtain multiwalled carbon nanotube reinforced poly(phenylene sulfide) (PPS) nanostructured composites by melt mixing technique and further characterization of their morphological and thermal properties. Transmission electronic microscopy and scanning electron microscopy analysis were performed to evaluate the quality of multi‐walled carbon nanotubes (MWCNT) dispersion throughout the PPS matrix. The incorporation of nanofiller in polymeric matrix was responsible for an increase in crystallinity due to heterogeneous nucleation phenomenon. In addition, Avrami, Ozawa, and Mo modeling were used to study the crystallization kinetics of MWCNT/PPS composites. It can be seen from TGA plots (thermogravimetric analysis) an increase in the maximum degradation temperature by the addition of nanofiller in polymeric matrix. POLYM. COMPOS., 38:604–615, 2017. © 2015 Society of Plastics Engineers     

Production and characterization of nanocomposites based on poly(amide-imide) containing 4,4′-methylenebis(3-chloro-2,6-diethylaniline) using nano-TiO2 surface-coupled by 3-aminopropyltriethoxysilane

In this work, the poly(amide-imide) (PAI) was synthesized from the polymerization reaction of 4,4′-methylenebis(3-chloro-2,6-diethyl trimellitimidobenzene) as a diacid with 4,4′-methylenebis(3-chloro-2,6-diethylaniline) under green condition using molten tetra-n-butylammonium bromide and triphenylphosphite. Ultrasonic technique was used for preparation of PAI/TiO₂ nanocomposites (PAI/TiO₂ NCs). For the improvement of TiO₂ nanoparticles (NPs) dispersion and enhancing interactions between NPs and polymeric matrix the surface of TiO₂ was successfully modified by silane coupling agent (3-aminopropyltriethoxysilane). The resulting NCs were characterized by FT-IR, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The TGA of the obtained NCs proves the enhancement in the thermal stability with an increase in the percentage of titania NPs. TEM and FE-SEM images showed that the NPs were uniformly dispersed in the polymer matrix. The shielding effect of nano TiO₂ under UV radiation was examined by UV–vis.     

Surface Treated Montmorillonite: Structural and Thermal Properties of Chiral Poly(Amide-Imide)/Organoclay Bionanocomposites Containing Natural Amino Acids

This work concerns the preparation of novel optically active nanocomposite materials derived from Cloisite Na⁺ clay, which has been functionalized by protonated l-methionine amino acid as a swelling agent for sufficient compatibilization with the poly(amide-imide) (PAI) matrix. The polymer chains were formed from the polycondensation reaction of N,N′-(pyromellitoyl)-bis-phenylalanine diacid chloride with 4,4′-diaminodiphenylether. Interaction between the two phases was established by modifying the PAI chains with amine end groups and free acid groups of the organoclay (OC). The effect of OC dispersion and the interaction between OC and PAI chains on the properties of resulting bionanocomposite material was studied using Fourier transform infrared spectroscopy, X-ray diffraction (XRD), transmission electron microscopy, field emission scanning electron microscopy and thermogravimetric analysis techniques. The XRD pattern and morphological investigation revealed the formation of intercalated and exfoliated OC platelets in the matrix. Because of the existence of naturally occurring amino acids as biological chiral resources, it is predictable that these materials may be potentially biodegradable and biocompatible.     

Enhancement of interfacial adhesion and dynamic mechanical properties of poly(methyl methacrylate)/multiwalled carbon nanotube composites with amine-terminated poly(ethylene oxide)

We have studied the dynamic mechanical behavior of poly(methyl methacrylate) (PMMA)/acidified multiwalled carbon nanotube (MWNT) composites compatibilized with amine-terminated poly(ethylene oxide) (PEO-NH₂). PEO-NH₂ is ionically associated with acidified MWNTs via ionic interaction as shown by XPS and FTIR. The miscibility between PEO and PMMA improves the interfacial adhesion between polymer matrix and MWNTs, leading to an increase in the storage modulus values of the composites. The effects of PEO-NH₂ on storage modulus and glass transition temperature are discussed.     

Preparation and characterization of reinforced poly(vinyl alcohol) films by a nanostructured,chiral, L-leucine based poly(amide-imide)/ZrO2 nanocomposite through a green method

In the present investigation, at first, the surface of ZrO₂ nanoparticles was modified with a bioactive and biocompatible diacid based on leucine amino acid as a coupling agent. The grafting of diacid on the surface of ZrO₂ was confirmed by Fourier transform infrared spectroscopy and thermogravimetric analysis. Then, the synthesis of poly(amide-imide)/ZrO₂ nanocomposite (PAI/ZrO₂ NC) was performed through ultrasonic technique. The obtained NCs demonstrated good thermal stability. Field emission scanning electron microscopy and transmission electron microscopy analysis showed that the average diameter of NP was around 15–20 nm. Finally, the resulting NC, was used as a nano-filler and was incorporated into the poly(vinyl alcohol) (PVA) in order to improve its mechanical and thermal properties. The PVA/PAI–ZrO₂ NC films were characterized by different techniques. The data indicated that the thermal and mechanical properties of the PVA/PAI–ZrO₂ NC were enhanced. It was attributed to the good dispersion of filler into the PVA matrix as a result of hydrogen bonding.     

Thermal and mechanical properties of phosphorylated multiwalled carbon nanotube/polyvinyl chloride composites

The fabrication of carbon nanotube/polyvinyl chloride (PVC) composites and a study of their thermal and mechanical properties are reported. Phosphorylated multiwalled carbon nanotube (p-MWCNT) and pristine MWCNT were used. The MWCNT were embedded in the polymer matrix through melt mixing. The phosphorylation of the MWCNT and their dispersion in the PVC matrix were characterized by scanning and transmission electron microscopy and Raman spectroscopy. Thermal analysis by thermal gravimetric analysis and differential scanning calorimetry, showed an increase in glass transition temperature and melting temperature for the composites with respect to pure PVC. The modulus of the MWCNT/PVC composites increased while there was a reduction in their tensile strength, indicating a decrease in polymer toughness.     

Scrutinization of Polystyrene Microsphere-grafted Multiwalled Carbon Nanotube and Silver Nanoparticle-based Hybrids: Morphology,Thermal Properties,and Antibacterial Activity

Polystyrene microsphere (emulsion polymerization) was grafted on pure multiwalled carbon nanotube and amine-modified multiwalled carbon nanotube. Silver nanoparticle was also decorated on nanotube using chemical reduction (dimethylformamide). Amine-modified multiwalled carbon nanotube secures better silver attachment on nanotube wall. Polystyrene/Ag–amine-modified multiwalled carbon nanotube depicted fine dispersion in polymer latex due to modification. The 10% decomposition temperature and maximum degradation temperature of polystyrene/Ag–amine-modified multiwalled carbon nanotube was increased to 352 and 424°C. Antibacterial properties of nanocomposite were studied against respiratory track demolishing Gram-positive Staphylococcus aureus bacteria and two Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). Ag nanoparticle was found responsible to potential death rate of microbes.     

Review Highlighting Physical Prospects of Styrenic Polymer and Styrenic Block Copolymer Reinforced with Carbon Nanotube

High-performance styrenic copolymers with carbon nanotube have invented technical relevance. Polystyrene is used to compensate different deficiencies of carbon nanotube within PS/carbon nanotube composite. Dispersion of carbon nanotube content is essential for enhanced mechanical and thermal performance of styrenic copolymer/carbon nanotube composite. Multiwalled carbon nanotube has been reinforced in styrene-butadiene rubber, nitrile butadiene rubber, hydrogenated nitrile butadiene rubber, poly(styrene-b-isoprene-b-styrene), acrylonitrile butadiene styrene, and other styrenic copolymers to enhance electrical, mechanical, and thermal properties. Viscoelastic and photoactuation study of polystyrene-grafted-multiwalled carbon nanotube has been performed. Different styrene-based copolymers show high resistivity toward high impact and are used in food packaging, electrical devices, medical appliance, construction materials, motor oils, sealants, and household purposes.