Surface grafting polymerization of N‐vinyl‐2‐pyrrolidone onto a poly(ethylene terephthalate) nonwoven by plasma pretreatment and its antibacterial activities

The objective of this research was the surface grafting polymerization of biocompatible monomer N‐vinyl‐2‐pyrrolidone (NVP) onto a plasma‐treated nonwoven poly(ethylene terephthalate) (PET) substrate with ultraviolet (UV)‐induced methods. The effects of various parameters, such as the monomer concentration, reaction time, initiator (ammonium peroxodisulfate) concentration, and crosslinking agent (N,N′‐methylene bisacrylamide) concentration, on the grafting percentage were studied. The grafting efficiency of the modified nonwoven PET surfaces reached a maximum at 50 min of UV irradiation and with a 30 wt % aqueous NVP solution. After the plasma activation and/or grafting, the hydrophobic surface of the nonwoven was modified into a hydrophilic surface. NVP was successfully grafted onto nonwoven PET surfaces. The surface wettability showed that the water absorption of NVP‐grafted nonwoven PET (NVP‐g‐nonwoven PET) increased with increasing grafting time. NVP‐g‐nonwoven PET was verified by Fourier transform infrared spectra and scanning electron microscopy measurements. An antibacterial assessment using an anti‐Staphylococcus aureus test indicated that S. aureus was restrained from growing in NVP‐g‐nonwoven PET. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 803–809, 2006     

Surface characterization of 8‐quinolinyl acrylate‐grafted poly(ethylene terephthalate) prepared by plasma glow discharge and it's antibacterial activity

Poly(ethylene terephthalate) (PET) film was exposed to oxygen plasma glow discharge to produce peroxides on its surface. These peroxides were then used as catalysts for the polymerization of 8‐quinolinyl acrylate (QA) to prepare the PET grafted with QA (PET‐Q). The surface‐modified PET was characterized by attenuated total reflection Fourier transform infrared spectroscopy (ATR‐FTIR) and X‐ray photoelectron spectroscopy (XPS). The introduction of QA to the PET surface was confirmed by observing the presence of nitrogen in the XPS survey scan and high‐resolution spectra. The amount of QA grafted on to the PET surface as measured by the gravimetric method was about 5.2 μg cm^?2. The antibacterial activity of the surface‐modified PET texture was investigated by using a shake‐flask and an inhibition zone test method. After 6 h of shaking, the PET grafted with QA showed the inhibition (91%) of the growth of the gram‐positive microorganism, S. aureus. Even after laundering ten times, an effectiveness of the inhibition was found. However, little inhibition was shown with the gram‐negative microorganism, K. pneumoniae. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 863–868, 2006     

Platelet adhesion on laser‐induced acrylic acid–grafted polyethylene terephthalate

To improve blood compatibility, acrylic acid (AAc) was grafted onto a polyethylene terephtalate (PET) film surface using lasers. The PET surface was irradiated with a CO₂ pulsed laser, and then graft copolymerization was carried out in an aqueous solution of AAc in the presence of Mohr's salt. Different techniques such as attenuated total reflectance Fourier transform infrared spectroscopy (ATR‐FTIR), scanning electron microscopy (SEM), and contact angle measurements were used to characterize the modified PET surface. The ATR‐FTIR spectra confirmed the creation of new functional groups on the PET surface, and contact angle measurements revealed that the hydrophilicity of the PET surface increased as a result of the AAc graft polymerization. The electron micrographs showed that the grafting changed the surface morphology of the PET film. To evaluate the blood compatibility in vitro, the number of platelets adhering to the modified PET surface was determined using lactate dehydrogenase (LDH) activity measurement. The data from LDH method indicated that the extent of platelet adherence on the unmodified PET was much higher than that on the AAc grafted PET. The morphology of adhered platelets on the PET surface was investigated by SEM. The results showed that platelet adhesion and activation onto the PET surface was reduced because of AAc graft polymerization. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3191–3196, 2002     

Synthesis and characterization of salep sulfate and its utilization in preparation of heavy metal ion adsorbent

A multicomponent polysaccharide obtained from dried tubers of certain natural terrestrial orchids was chemically modified by sulfonation using chlorosulfonic acid–dimethylformamide (HClSO_3–DMF) complex as a reagent. For a structural characterization of salep sulfate ¹H nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectra, and Thermogravimetric analysis (TGA) curves were recorded. The sulfate content of modified salep was determined using elemental analysis. This modified biopolymer was used to prepare a new environment‐friendly heavy metal ion adsorbent, salep sulfate‐graft‐polyacrylic acid hydrogel (SS‐g‐PAA). Swelling rate and equilibrium water absorbency in various pH and saline solutions were investigated to study the effect of salep sulfate on swelling behavior of the hydrogel. In addition, the effect of sulfate content on heavy metal ion adsorption from aqueous solution was investigated. The results show that SS‐g‐PAA can effectively remove heavy metal ions (Co²⁺, Zn²⁺, Cu²⁺) from aqueous solution and swelling behavior of the hydrogels highly dependent on the amount of sulfate group on corresponding modified polysaccharide. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3001–3008, 2013     

End-capped fluoroalkyl-functional silanes. Part II: Modification of polymers and possibility of multifunctional silanes

This work reports the fluoroalkylation of polymer surfaces using novel oligomeric silanes having end-capped fluoroalkyl groups. Polymer surfaces such as cellulose, poly(ethylene terephthalate) (PET), polyethylene, and poly(methyl methacrylate) (PMMA) etc. were effectively modified by these oligomeric silanes as well as the glass surface. From the contact angle measurements, the dispersive and polar components of surface free energies were reduced to 15–20 and 1–3 mJ/m², respectively, and the surfaces were shown to be both highly water- and oil-repellent. Modified cellulose and PET surfaces were analyzed using XPS measurements. In the case of cellulose, a linear correlation was observed between the dispersive component of surface free energy γ_S ^d and the area ratio of the F1s peak to the Si2p peak. In the case of PET, the hickness of siloxane layer on the surface was shown to be less than 8 nm. The modified PET surface showed a high solvent durability against common organic and inorganic solvents except fluorochemicals and alkalis. The structure of the siloxane layer on the modified surface is discussed in terms of a network interphase model. It was also shown to be quite easy to add another function such as hydrophilicity (flip-flop character) and/or antibacterial property in addition to the water- and oil-repellency imparted by fluoroalkyl groups.     

Preparation of hydrophilic woven fabrics: Surface modification of poly(ethylene terephthalate) by grafting of poly(vinyl alcohol) and poly(vinyl alcohol)-g-(N-vinyl-2-pyrrolidone)

One of the most industrially important synthetic textile materials, woven poly(ethylene terephthalate) (PET) fabrics, have limitations in the usage of casual apparel applications due to their unwanted hydrophobicity. For that reason, in this study, to impart permanent hydrophilicity to the PET fabrics, hydrophilic poly(vinyl alcohol) (PVA) and a PVA-based copolymer were introduced to the alkaline hydrolysis pretreated PET surface by graft copolymerization for the first time. The graft modification of PET fabric surface was performed with an industrial-adaptable approach. The synthesis of a novel PVA-g-(N-vinyl-2-pyrrolidone) copolymer was achieved by the introduction of glycidyl methacrylate monomer to the PVA backbone. The structure of the copolymer was evidenced by attenuated total reflection–Fourier transform infrared spectroscopy and ¹H-NMR techniques. The introduction of PVA and copolymer structures with desired functional groups to the PET fabric surface was confirmed with the X-ray photoelectron spectroscopy technique. It was obtained that the contact angle–wetting time of PET fabric (145° and 98 s) could be dropped to 37° and 0.1 s and 64° and 0.7 s after PVA and copolymer grafting, respectively. This suggests that the graft-modified PET fabrics may find the potential of use in the textile applications as the alternative hydrophilic materials. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48584.     

Effects of aromatic groups in polymer chains on plasma surface modification

Three polyester films with different repeating units—poly(lactic acid) (PLA), poly(ethylene terephthalate) (PET), and poly(oxybenzoate‐co‐oxynaphthoate) (PBN)—were modified by plasma, and the way in which the chemical compositions of the polymer chains influenced the plasma modification was investigated with contact‐angle measurements and X‐ray photoelectron spectroscopy (XPS). There were large differences in the compensated rates of weight loss among the three polyester films when they were exposed to Ar and O₂ plasmas. The PLA film showed the highest rate for weight loss of the three films, and the PBN film showed the lowest rate. The PET and PBN film surfaces were modified to become more hydrophilic by either argon or oxygen plasma. However, the PLA film surface was not made more hydrophilic by the plasmas. XPS spectra showed that the PLA film surface was not modified in its chemical composition, but the PBN film surface was modified in its chemical composition to form C? O groups in the PBN polymer chains. The reason that the PLA film surface was not modified but the PBN film surface was modified was examined. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 96–103, 2003     

Nonisothermal crystallization kinetics of poly(ethylene terephthalate) and poly(methyl methacrylate) blends

The nonisothermal crystallization kinetics of poly(ethylene terephthalate) (PET) and poly(methyl methacrylate) (PMMA) blends were studied. Four compositions of the blends [PET 25/PMMA 75, PET 50/PMMA 50, PET 75/PMMA 25, and PET 90/PMMA 10 (w/w)] were melt‐blended for 1 h in a batch reactor at 275°C. Crystallization peaks of virgin PET and the four blends were obtained at cooling rates of 1°C, 2.5°C, 5°C, 10°C, 20°C, and 30°C/min, using a differential scanning calorimeter (DSC). A modified Avrami equation was used to analyze the nonisothermal data obtained. The Avrami parameters n, which denotes the nature of the crystal growth, and Z_t, which represents the rate of crystallization, were evaluated for the four blends. The crystallization half‐life (t_½) and maximum crystallization (t_max) times also were evaluated. The four blends and virgin polymers were characterized using a thermogravimetric analyzer (TGA), a wide‐angle X‐ray diffraction unit (WAXD), and a scanning electron microscope (SEM). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3565–3571, 2006     

A novel method of modifying poly(ethylene terephthalate) fabric using supercritical carbon dioxide

For the modification of poly(ethylene terephthalate) (PET) fabric, a type of epoxy compound, glycerol polyglycidyl ether (GPE), was impregnated as a cross‐linking agent into PET fabric by means of supercritical carbon dioxide (scCO₂), then, a series of immobilization processes were implemented, including the pad‐dry‐cure process and the solution process to finish the GPE‐PET fabric with natural functional agents (sericin, collagen, or chitosan). Chloroform was found to be an effective cosolvent, as evidenced by the mass transfer of GPE to PET during the treatment with scCO₂. Chemical analyses by X‐ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy showed that GPE can penetrate the surface of the PET fabric in scCO₂ pretreatment process, and natural functional agents (sericin, collagen, or chitosan) can also be immobilized on the surface of the GPE‐PET fabric especially for the method of pad‐dry‐cure. The nitrogen content in the modified PET fabrics was calculated accurately and confirmed by combustion analysis. The modified PET fabric displayed improvements in surface wettability, moisturization efficiency, and antibacterial characteristics against S. aureus, which demonstrated that the feasibility of this design for immobilizing natural functional agents (sericin, collagen, or chitosan) onto the surface of the PET fabric. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Fabrication of speedy and super‐water‐absorbing non‐woven cloth with hierarchical three‐dimensional network structure

A novel speedy and super‐water‐absorbing non‐woven cloth with hierarchical three‐dimensional network (3D‐SS‐PET) was fabricated through the induction of UV copolymerization on polyethylene terephthalate (PET) fibers followed by a volume phase transition. The macroscopic three‐dimensional network implied that the PET non‐woven substrates are complicated three‐dimensional fibrous materials including oriented fibers in preferential or random directions. The microscopic three‐dimensional network is poly(acrylic acid‐co‐acrylamide) (poly(AA‐co‐AM)) crosslinked copolymer layers on the fiber surface. The rapid volume phase transition was achieved by immersing the swelled non‐woven poly(AA‐co‐AM) modified PET (PET‐g‐AA‐co‐AM) in ethanol. The above process was an essential step to prepare the copolymer chain; after that the fiber surface was extended to form abundant capillary channels and plenty of space between fibers. The water contact angle decreased remarkably from 130° to 0°, while the absorbing capacity of the saturated water and the average water‐absorbing rate experienced an increasing trend, rising from 300 to 324.6 g g^?1 in 24 h and 18.6 and 222 g (g min)^?1 in 40 s, respectively. It was concluded that surface hydrophilicity and capillaries of the hydrophilic modified macroscopic fibrous structure enhanced the water‐absorbing rate and the swelling process contributed to the higher water absorption capacity. This speedy and super‐water‐absorbing material exhibits great potentiality in diapers, sanitary napkins, wound dressings, surgical pads, and hygroscopic and sweat‐free underwear in extremely cold areas. © 2018 Society of Chemical Industry     

Antimicrobial polyethylene terephthalate (PET) treated with an aromatic N‐halamine precursor,m‐aramid

A commercial m‐aramid as N‐halamine precursor has been coated onto polyethylene terephthalate (PET) fabric surface by pad‐dry‐curing process. The process is accomplished by padding the scoured PET fabric through the homogeneous m‐aramid solution, drying at 150°C for 3 min, and curing at 230°C for 3 min. The PET surface coated with m‐aramid was characterized using fourier transform infrared‐attenuated total reflection (FTIR‐ATR) spectroscopy, X‐ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). FTIR exhibits new bands in the 1645 and 1524 cm^?1 regions as characteristic of m‐aramid bands, which indicate the PET fabric coated with m‐aramid. XPS results show a distinguishable peak at binding energy 398.7 eV, which confirms the nitrogen atom of m‐aramid on the PET surface. In addition, SEM image shows a layer of coating onto the PET surfaces, which demonstrates the presence of m‐aramid coating on the surface of the PET. After exposure to dilute sodium hypochlorite solution, exhibition of antimicrobial activity on the coated PET is attributed to the conversion of N‐halamine moieties from the N‐halamine precursor. The chlorinated PET showed high antimicrobial activity against Gram‐negative and Gram‐positive bacteria. The chlorinated PET coated with 10% m‐aramid exhibited about 6 log reductions of S. aureus and E. coli O157:H7 at a contact time of 10 and 30 min, respectively. Furthermore, the antimicrobial activity was durable and rechargeable after 25 wash cycles. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Study on the grafting of PET onto the glass fiber surface during in situ solid‐state polycondensation

An in situ solid‐state polymerization process was developed to produce long glass fiber reinforced poly(ethylene terephthalate) (PET) composites. As reported in our last article, one advantage of this new process is that the good wetting of reinforcing fiber can be obtained for using low‐viscosity oligomer as raw materials. In this article, the grafting of PET macromolecular chain onto the surface of reinforcing glass fiber during in situ solid‐state polycondensation (SSP) will be investigated, which was believed to be another advantage for this new process and should be very important for thermoplastic composite. The reinforcing glass fiber after removing ungrafted PET from a long glass fiber reinforced PET composite by solvent extraction was investigated by SEM, pyrolysis‐gas chromatography mass spectrometry (Py‐GC/MS), DSC, and FTIR. The information from morphology of SEM photos of glass fiber surface, the spectrum of Py‐GC/MS, the melt peak at differential scanning calorimetric (DSC) curve, and the spectrum of Fourier transform infrared Raman spectroscopy (FTIR) gave a series evidence to prove the presence of grafted PET layer on the surface of silane‐coupling‐treated glass fiber. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 775–781, 2006     

Biocompatible surface modification of poly(ethylene terephthalate) focused on pathogenic bacteria: Promising prospects in biomedical applications

Poly(ethylene terephthalate)—PET, is one of the most common polyesters, widely used in biomedical applications ranging from catheters to stents, vascular grafts, heart valves, sutures, and scaffolds. PET surface modification is necessary to impart desired properties for biomedical applications, making the polymer biocompatible, noncytotoxic and antibacterial that can preferably resist biofilm formation caused by pathogenic bacteria. A novel approach to anticorrosive wet chemical surface modification of PET by insertion of alkyl and hydroxyl groups was achieved by using Grignard reagents and confirmed by several different characterization methods including Fourier transform infrared spectroscopy (FTIR), water contact angle (WCA) measurement, free surface energy (FSE) measurement, scanning electron microscopy (SEM), and atomic force microscopy (AFM). High antibacterial efficiency against four different types of biofilm active, pathogenic bacterial strains namely: Staphylococcus aureus, Escherichia coli, methicillin‐resistant S. aureus (MRSA), and Pseudomonas aeruginosa was established on the modified PET surface. Biocompatibility higher than 84% of the modified samples has been proved. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44990.     

Regenerability of antibacterial activity of interpenetrating polymeric N‐halamine and poly(ethylene terephthalate)

Effective antibacterial modification of poly(ethylene terephthalate) (PET) was achieved by forming a surface thermoplastic semi‐interpenetrating network of polyacrylamide (PAM) and PET, followed by converting the immobilized amides to N‐halamine. The regenerability of N‐halamine on PAM‐modified PET was significantly influenced by the cross‐linkers used to form the network. Through Fourier transform infrared spectroscopy and nitrogen content analysis of the materials for up to 29 regeneration cycles, it was found that breaking down of the PAM network in chlorination accounted for the loss of regenerability. The relationship between antibacterial efficacy and N‐halamine concentration was also studied. Compared with N,N′‐methylenebisacrylamide and 2‐ethyleneglycol diacrylate, cross‐linker divinylbenzene can generate more durable PAM network. After 29 regeneration cycles, the PAM‐divinylbenzene network‐modified PET was still able to provide 100% reduction of healthcare‐associated methicillin‐resistant Staphylococcus aureus in 20 min contact. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Facile fabrication of polyester filament fabric with highly and durable hydrophilic surface by microwave‐assisted glycolysis

Poly(ethylene terephthalate) (PET) fabric with highly and durable hydrophilic surface was fabricated using microwave‐assisted glycolysis. Sodium hydroxide (NaOH) as a catalyst was proven to be suitable for PET glycolysis under assistance of microwave. The modified PET fabric (0.5% NaOH, irradiation 120 s) showed high surface hydrophilicity with a contact angle of 17.4 ° and a wicking length of 19.36 mm. The exposure of the carboxyl‐ and hydroxyl‐end groups on the surface of PET and the introduction of etches were confirmed by Methylene Blue staining and field emission scanning electron microscopy (FESEM), receptively. Although the strength of PET fabric decreased after modification, it was still high enough for textile applications. The thermal properties of the modified PET fabrics were well maintained. The high hydrophilicity and its original properties of PET could be controlled by changing the irradiation time from 60 s to 120 s and adjusting the content of sodium hydroxide from 0.2% to 0.5%. These results suggest microwave‐assisted glycolysis with sodium hydroxide is an effective method for PET hydrophilic finishing. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44069.     

Properties of poly(ethylene terephthalate)–poly(ethylene naphthalene 2,6‐dicarboxylate) blends with montmorillonite clay

The production and properties of blends of poly(ethylene terephthalate) (PET) and poly(ethylene naphthalene 2,6‐dicarboxylate) (PEN) with three modified clays are reported. Octadecylammonium chloride and maleic anhydride (MAH) are used to modify the surface of the montmorillonite–Na⁺ clay particles (clay–Na⁺) to produce clay–C18 and clay–MAH, respectively, before they are mixed with the PET/PEN system. The transesterification degree, hydrophobicity and the effect of the clays on the mechanical, rheological and thermal properties are analysed. The PET–PEN/clay–C18 system does not show any improvements in the mechanical properties, which is attributed to poor exfoliation. On the other hand, in the PET–PEN/clay–MAH blends, the modified clay restricts crystallization of the matrix, as evidenced in the low value of the crystallization enthalpy. The process‐induced PET–PEN transesterification reaction is affected by the clay particles. Clay–C18 induces the largest proportion of naphthalate–ethylene–terephthalate (NET) blocks, as opposed to clay–Na⁺ which renders the lowest proportion. The clay readily incorporates in the bulk polymer, but receding contact‐angle measurements reveal a small influence of the particles on the surface properties of the sample. The clay–Na⁺ blend shows a predominant solid‐like behaviour, as evidenced by the magnitude of the storage modulus in the low‐frequency range, which reflects a high entanglement density and a substantial degree of polymer–particle interactions. Copyright © 2005 Society of Chemical Industry     

Crystallization behavior and UV‐protection property of PET‐ZnO nanocomposites prepared by in situ polymerization

The aim of this study was to investigate the crystallization behavior and UV‐protection property of polyethylene terephthalate (PET)‐ZnO nanocomposits. PET‐ZnO nanocomposites containing 0.5–3.0 wt % of ZnO were successfully synthesized by in situ polymerization. The Fourier transformed infrared (FTIR) spectroscopy indicated the silane coupling agent was anchored onto the surface of ZnO. Scanning electron microscope (SEM) images showed ZnO particles were dispersed homogeneously in PET matrix with amount of 0.5–1.0 wt %. Differential scanning calorimetry (DSC) results exhibited that the incorporation of ZnO into PET resulted in increase of the melting transition temperature (T_m) and crystallization temperature (T_c) of PET‐ZnO nanocomposites. The crystallization behavior of PET and PET‐ZnO nanocomposites was strongly affected by cooling rate. ZnO nanoparticles can act as an efficient nucleating agent to facilitate PET crystallization. UV–vis spectrophotometry showed that UV‐ray transmittance of PET‐ZnO nanocomposites decreased remarkably and reached the minimum value of 14.3% with 1.5 wt % of ZnO, compared with pure PET whose UV‐ray transmittance was 84.5%. PET‐ZnO nanocomposites exhibited better UV‐protection property than pure PET, especially in the range of UVA. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effects of the surface modification of poly(amino acid)/hydroxyapatite/calcium sulfate biocomposites on the adhesion and proliferation of osteoblast‐like cells

In this study, we focused on the surface modification of a novel poly(amino acid) (PAA)/hydroxyapatite/calcium sulfate composite and the effect of its surface modification on cellular responses. The surface modification was performed by sandblasting (sample S2), calcium chloride ethanol saturated solution etching (sample S3), and formic acid etching (sample S4) followed by in vitro culturing of osteoblast‐like cells. The obtained results indicate that a new interface of the composite was formed during the modification, and the modified surface was changed with respect to its surface morphology by physical abrasion. The calcium chloride ethanol saturated solution etchant etched PAA selectively whereas forming rich calcium‐phosphate (Ca–P) apatite on the surface of S3. The formic acid etchant attacked the inorganic component without changing the PAA state. Cell attachment and cell proliferation were improved by the treatments of S2 and S3 in comparison with no treatment and the treatment of S4 © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42427.     

Conductive polyaniline–polythiophene/poly(ethylene terephthalate) composite fiber: Effects of pH and washing processes on surface resistivity

A conductive polyaniline (PAn)–polythiophene (PTh)/poly(ethylene terephthalate) (PET) composite fiber was prepared by polymerization of aniline and thiophene in the presence of PET fibers in an organic medium with FeCl₃. The effects of polymerization conditions, such as polymerization medium, mol ratios of aniline/thiophene and FeCl₃/aniline‐thiophene as well as polymerization temperature and time, were investigated on PAn–PTh content (%) and surface resistivity of the composite. The composite with the lowest surface resistivity (1.30 MΩ/cm²) was obtained by polymerization of aniline and thiophene (1/3 mol ratio) in acetonitrile/chloroform (1/5 volume ratio) at 20°C. The surface resistivity of the PAn–PTh/PET composite containing 4.8% PAn–PTh was increased from 1.9 MΩ/cm² to 270 MΩ/cm² at pH 11. The washing durability of the composites was determined with domestic and commercial laundering processes by monitoring the surface resistivity and morphology. The composite was also characterized with FTIR, TGA, elemental analysis, optic microscope and SEM techniques. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41979.     

Thermal,mechanical, and barrier properties of polyethylene terephthalate‐platelet nanocomposites prepared by in situ polymerization

This study used in situ polymerization to prepare polyethylene terephthalate (PET) nanocomposites incorporating Ethoquad‐modified montmorillonite (eMMT), unmodified hectorite (HCT), or phenyl hectorite (phHCT) particles to study the impact of platelet surface chemistry and loading on thermal, mechanical, and gas barrier properties. eMMT platelets reduced the PET crystallization rate without altering the ultimate degree of crystallinity. In contrast, HCT and phHCT platelets accelerated the polymer's crystallization rate and increased its crystallinity. DMA results for thermally‐quenched samples showed that as T increased past glass transition temperature (T_g), HCT and phHCT nanocomposites (and control PET) manifested precipitous drops in G′ followed by increasing G′ due to cold crystallization; in contrast, eMMT nanocomposites had much higher G′ values around T_g. This provides direct evidence of eMMT reinforcement in thermally‐quenched eMMT nanocomposites. These results suggest that eMMT has a strong, favorable interaction with PET, possibly through Ethoquad‐PET entanglement. HCT and phHCT have a fundamentally different interaction with PET that increases crystallization rate and T_g by 11 to 17°C. Water barrier improvement in eMMT nanocomposites agrees with previously published oxygen barrier results and can be rationalized in terms of a tortuous path gas barrier model. POLYM. ENG. SCI., 52:1888–1902, 2012. © 2012 Society of Plastics Engineers