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Nylon 11, which can be found in many commercial products, is a synthetic plastic that has previously been considered non-biodegradable. Increasing nylon 11 and other plastics in landfills and in the environment pose an environmental concern. Recent studies on plastic biodegradation revealed that initial mechanical fragmentations increase the rate of degradation. In this study, we discovered that the larvae of mealworm (Tenebrio molitor) can masticate nylon 11 film at the rate of 0.25 ± 0.07 mg per fifty larvae per day. The body mass of larvae did not differ from that of starvation control while feeding on nylon 11. Comparison of gut microbiota in nylon-fed and starving larvae showed a shift in composition. There was a significant variation in community composition among the nylon 11-fed experimental groups, suggesting that many organisms are capable of metabolizing nylon 11 fragments and/or possess a growth advantage in a nylon-fed gut environment. We also discovered that a significant fraction of gut microbiome of control larvae is capable of metabolizing nylon 11 monomer (11-aminoundecanoic acid) even in the absence of prior exposure to nylon 11. This is the first study demonstrating ingestion of nylon polymers by invertebrates, and our results suggest the potential of mealworm larvae for nylon 11 biodegradation applications.

The aim of this work was to study the crystallization kinetics and melting behaviour of polymer blend nanocomposites based on poly (L-lactic acid) (PLLA), nylon 11 and tungsten disulfide nanotubes (INT-WS2), which are layered transition metal dichalcogenides (TMDCs), using non-isothermal differential scanning calorimetry (DSC). Blends containing different nylon 11 contents ranging from 20 to 80 wt.% with or without INT-WS2 were prepared by melt mixing. Evaluation of their morphology with high-resolution SEM imaging proved that the incorporation of inorganic nanotubes into the immiscible PLLA/nylon 11 mixtures led to an improvement in the dispersibility of the nylon 11 phase, a reduction in its average domain size and, consequently, an increase in its interfacial area. The crystallization temperatures of these PLLA/nylon 11-INT blends were influenced by the cooling rate and composition. In particular, the DSC results appear to demonstrate that the 1D-TMDCs WS2 within the PLLA/nylon 11-INT blend nanocomposites initiated nucleation in both polymeric components, with the effect being more pronounced for PLLA. Moreover, the nucleation activity and activation energy were calculated to support these findings. The nucleation effect of INT-WS2, which influences the melting behaviour of PLLA, is highly important, particularly when evaluating polymer crystallinity. This study opens up new perspectives for the development of advanced PLA-based nanomaterials that show great potential for ecological and biomedical applications. [ABSTRACT FROM AUTHOR]

Traditional wastewater treatment methods using nanoparticles (NPs) encounter challenges with catalyst recovery. In this study, we fabricated a Nylon 11 nanofibrous membrane (NFM) via electrospinning and functionalized it with polydopamine (PDA) to immobilize Ag-ZnO NPs for photocatalytic degradation of organic pollutants. The Nylon 11 NFM was treated with a dopamine tris buffer solution for PDA coating, which facilitated mussel-inspired attachment of the ZnO NPs. These NPs served as a nucleation site for the biomimetic nucleation of Ag-ZnO NPs during the hydrothermal process. The synthesized composite membrane was characterized by various microscopic and spectroscopic techniques. The water contact angle decreased from 135° (Nylon 11 NFM) to 41° (PDA/Nylon 11 NFM) and the filtration efficiency improved 10 folds (from 15.92 Lm-2h−1 to 170.60 Lm−2 h−1) at ambient conditions. The Ag-ZnO/PDA/Nylon 11 NFM showed strong antimicrobial activity against different bacterial strains and excellent photocatalytic degradation for methyl orange with a rate constant of 0.0431 min−1, significantly surpassing other configurations. The membrane exhibited excellent stability, reusability and consistent photocatalytic efficiency over multiple cycles. It is easily recoverable from the reaction mixture, and suitable for repeated use, making it a promising candidate for environmental remediation due to its antibacterial properties, photocatalytic activity, enhanced filtration efficiency, and reusability. • Bioresource based Nylon 11 NFM surface modified with facile polymerization of PDA. • PDA eased the seeding of the ZnO NPs, and Ag-ZnO nucleation at the fiber surface. • PDA enhanced concentration gradients of MO at NFM and the photocatalytic activity. • Ag-ZnO NPs were strongly adhered to NFM, facilitates recycling applications. • Photocatalytic and antibacterial and water filtration efficiency was enhanced. [ABSTRACT FROM AUTHOR]

The current research discusses the reactive compatibilization of nylon 11 (PA11) and polypropylene (PP) using maleic anhydride grafted PP (PP‐g‐MA) through an extruder. PP phase is dispersed in PA11 by coalescence and droplet break‐up mechanism by using polyhydroxybutyrate (PHB) as a dispersion agent that induces uniform interaction between the blend components. The reactive compatibilization ensures the mixing of polymers, and the consistent interaction of phases is controlled by dispersion. All of the blends were processed through melt processing at different compositions using a twin‐screw extruder. Scanning electron microscopy was used to determine the morphologies of the binary and ternary blends. Surface tension and interfacial tension of the homopolymer characterizes the interaction of the polymers at interphase. The interaction of PHB/PA11 appeared preferable than that of PHB/PP, elaborating on the efficient dispersion and droplet formation of the PP phase. The compatibilizer maleic anhydride grafted PP (PP‐g‐MA) imparts a drastic effect on the compatibility of PA11‐PP and PA11‐PHB‐PP blends and reduces PP phase particle size, which indicates the affinity of PHB and PP. The encapsulation of PP by PHB was seen in the expectation of minimum free energy models. The rheological measurements were used to understand the phase separation within blends. These measurements were also applied to understand the interaction between PA11‐PP‐PHB phases. The modulus values and viscosity ratio of the blends were measured to follow the chain relaxation in the melt. In the Cole–Cole plot, it was found that the reduction in PP phase size influences the relaxation of chains of blends. [ABSTRACT FROM AUTHOR]

Nylon 11/CaCu3Ti4O12 (CCTO) nanocomposites were prepared via solution casting method followed by vacuum drying and characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy, scanning electron microscopy (SEM), differential scanning calorimetry, thermo-gravimetry (TG) and impedance analyzer for their structural, thermal and dielectric properties. The presence of γ-phase of nylon 11 both in the pure nylon 11 cast film as well as in the nylon 11/CCTO nanocomposites was confirmed using XRD analysis. Distribution of CCTO nanofillers into nylon 11 matrix was almost uniform according to SEM analysis. The shift in endothermic peak and new IR absorption bands indicated possible interaction between nylon 11 and CCTO. TG results showed that the composites have better thermal stability than pure polymer. Activation energies calculated using Flynn–Wall–Ozawa, Friedman, and Coats–Redfern methods further support the fact that the composites have better thermal stability. A kinetic model consisting of two parallel reactions was proposed for the thermal degradation process of nylon 11 as well as its 30 mass% CCTO nanocomposite. The proposed model was also verified by comparing the experimental and simulated conversion curves. For nylon 11/CCTO-30 mass% nanocomposite, room temperature dielectric permittivity as high as 168 at 50 Hz has been achieved indicating the possibility of using these materials for high-energy-density capacitor applications. [ABSTRACT FROM AUTHOR]

Flexible nylon 11/CaCu 3 Ti 4 O 12 (CCTO) nanocomposite films (thickness ∼100 μm) with varying CCTO nanoceramics (0 to 30 wt%) were fabricated by solution casting method followed by vacuum drying. The nanocomposites were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy, and impedance analyzer to study their structural and dielectric properties. XRD analysis revealed the presence of γ-phase of nylon 11 both in as-cast film as well as in the composites. SEM micrographs indicated that the CCTO nanocrystals were distributed evenly throughout the nanocomposite films with less agglomeration. The room temperature dielectric permittivity was 168 at 50 Hz when the CCTO content increased to 30 wt% in the polymer and this was increased to 1007 at 423 K. Frequency independent dielectric behavior was observed for the frequency range of 100 kHz–10 MHz. Temperature coefficient of permittivity showed that the permittivity of the nanocomposites is highly temperature dependent. [ABSTRACT FROM AUTHOR]

The aim of this study was to identify the optimum set of tests required for quality assurance purposes when selectively laser sintering polyamide powders. Both Nylon 11 and Nylon 12 powders are considered, and the tensile, flexural and impact properties are assessed, together with dimensional accuracy, density and melt flow index (MFI). It is concluded that MFI and strength are key measures, with impact strength the preferred strength measure because of its practicality. The MFI and strength measures may be augmented by assessment of dimensional accuracy and density for particular applications. Additional testing beyond these measures did not provide further significant information with regard to the mechanical integrity or dimensional accuracy of the output from a build. [ABSTRACT FROM AUTHOR]

Nanocomposites of recycled nylon 11 and titanium based nanofillers were manufactured and their thermal and mechanical behavior analyzed. The nanofillers used vary in dimensions, being classified as 0-dimension (nanoparticles) and 1-dimension (nanofibers). The results show that dispersion of the fillers was the key variable governing the thermal and mechanical properties of the composites. The best performance was obtained for composites loaded with 1% and 5% of TiO 2 nanoparticles. For these composites, a 4 fold increase in the Young's modulus was obtained, although the deformation at rupture showed a decrease of almost 50%. The flow curve characteristics at the region of necking stabilization were correlated to a strain-hardening coefficient. It was postulated that the value of this strain hardening coefficient could be used as a measure of neck instability. [ABSTRACT FROM AUTHOR]

In this study, measurements of nylon 11 pipes subjected to ageing at 40 ℃, 70 ℃ and 100 ℃ in water, methanol and xylene using both a constant pressure of 200 bar and a cyclic pressure regime are reported. Gravimetric measurements indicate the rate at which the solvent is absorbed by the polymer, and differential scanning calorimetry follows the changes in the crystallinity as the materials are aged. Dramatic changes in the tensile properties are observed when the pipes are subjected to high pressure and reflect a relaxation of the stress in the matrix introduced by the quenching process when the pipes were extruded. The magnitude of the change varies with the fluid and reflects their relative abilities to be absorbed by the polymer. Measurements of the relative viscosity for the polymer indicated that in the case of water and methanol, hydrolytic degradation of the polymer is time-dependent. The impact of the morphological changes in the dynamic mechanical properties revealed the movement of elasticity transition to higher temperatures and reduction in the chain mobility with time. Changes in the mechanical properties are a function of the initial stress relaxation and chain scission as a consequence of degradation and thermodynamically driven morphological changes increasing the crystallinity and embrittling the polymer. As the pipes aged the burst pressures progressively decreased. Examination of the failure surfaces indicated brittle failure and clear evidence of environmental stress cracking. Whilst the data indicate that the pipes might be used effectively for hydrophobic fluids, hydrophilic fluids and in particular methanol can significantly shorten their effective life. [ABSTRACT FROM PUBLISHER]

Nylon 11, which can be found in many commercial products, is a synthetic plastic that has previously been considered non-biodegradable. Increasing nylon 11 and other plastics in landfills and in the environment pose an environmental concern. Recent studies on plastic biodegradation revealed that initial mechanical fragmentations increase the rate of degradation. In this study, we discovered that the larvae of mealworm ( Tenebrio molitor ) can masticate nylon 11 film at the rate of 0.25 ± 0.07 mg per fifty larvae per day. The body mass of larvae did not differ from that of starvation control while feeding on nylon 11. Comparison of gut microbiota in nylon-fed and starving larvae showed a shift in composition. There was a significant variation in community composition among the nylon 11-fed experimental groups, suggesting that many organisms are capable of metabolizing nylon 11 fragments and/or possess a growth advantage in a nylon-fed gut environment. We also discovered that a significant fraction of gut microbiome of control larvae is capable of metabolizing nylon 11 monomer (11-aminoundecanoic acid) even in the absence of prior exposure to nylon 11. This is the first study demonstrating ingestion of nylon polymers by invertebrates, and our results suggest the potential of mealworm larvae for nylon 11 biodegradation applications., Competing Interests: Conflict of interest: The authors declare no conflict of interest., (© 2022 the Author(s), licensee AIMS Press.)

Reactive blending of syndiotactic 1,2-polybutadine (SPB) and nylon 11 was carried out with a twin-screw extruder to obtain a thermoplastic vulcanizate (TPV) with good mechanical properties. A lamellar structure formed by continuous nylon 11 phase and long filamentous ligaments of SPB was observed for the TPV sample with a transmission electron microscope. Infrared spectra of nylon 11 films casted on SPB films show that chemical bonds between nylon 11 and SPB were formed after the curing of the films. Good mechanical properties of the TPV, which were owed to its morphology and strong adhesion at the interface, were investigated by peel tests and tensile tests. [ABSTRACT FROM AUTHOR]

Nylon 11/ethylene-vinyl alcohol (EVOH)/dicumyl peroxide (DCP) blends were prepared using a single-screw extruder. The Fourier transcript infrared spectroscopy results showed that strong interactions existed and co-crystallization formed between nylon 11 and EVOH in the presence of DCP. The crystalline morphology and melting behavior was investigated by means of Wide-angle X-ray diffraction (WAXD), polarized optical microscope (POM) and differential scanning calorimetry, respectively. The WAXD indicated that no crystal structure transition occurred for both nylon 11 and EVOH after the addition of DCP. The spherulites size of nylon 11 became smaller and crystalline bands of EVOH formed in the presence of DCP as revealed by POM observation. Both nylon 11 and its blends exhibited two melting endotherms. The equilibrium melting point for blends was lower than that of nylon 11, it was indicated that the mobility of nylon 11 was hindered after the addition of EVOH and DCP. [ABSTRACT FROM AUTHOR]

Abstract: Nylon 11/tetrapod-shaped zinc oxide whisker (T-ZnOw) composites were prepared via melt blending in a co-rotating twin-screw extruder. The mechanical properties, morphology and crystal structure were investigated. The tensile strength was increased by 15.7% as adding of 15phr T-ZnOw, while the optimum values of room temperature and low temperature (−40°C) notched Izod impact strength was increased by 281% and 65% as adding 5phr and 8phr T-ZnOw, respectively. The morphologies showed that the addition of T-ZnOw resulted in the formation of “terrace” structure and stress whitening, both which can be attributed to improve the toughness of the composites. The different crystal forms in the inner and skin layer were observed, and the intensity of the crystal was affected by the incorporation of T-ZnOw. [Copyright &y& Elsevier]

Nylon 11/ethylene-vinyl alcohol (EVOH) composites with various concentration of dicumyl peroxide (DCP) were prepared using a single-screw extruder. The influence of DCP concentration on the mechanical properties and rheological behavior of nylon 11/EVOH composites as well as gel content was investigated. The experimental results showed that the impact and tensile strength were significantly improved when the DCP loading was in the range of 1.0~1.5 wt% while the elongation at break reduced. All nylon 11/EVOH melts with and without DCP were pseudoplastic and exhibited shear-thinning behavior. The apparent viscosity of composites was increased dramatically with the addition of DCP and was up to the maximum value at 1.5 wt% DCP level, which indicated that the interfacial adhesion owe to co-crosslinking between nylon 11 and EVOH was increased markedly. [ABSTRACT FROM AUTHOR]

Abstract: Differential scanning calorimetry (DSC) was used to investigate the non-isothermal crystallization kinetics and melting behaviors of nylon 11/T-ZnOw composites. For non-isothermal studies, the Avrami equation modified by Jeziorny, the Ozawa model and the equation combining the Avrami and Ozawa theories were employed. It was found that the Ozawa model failed to describe the non-isothermal crystallization process for both nylon 11 and nylon 11/ T-ZnOw composites, while the Avrami equation modified by Jeziorny and the equation combining the Avrami and Ozawa theories exhibited great advantages in treating the non-isothermal crystallization kinetics and gave good results. The results showed that the addition of T-ZnOw influenced the mechanism of non-isothermal crystallization and promoted the crystallization rate of PA11 matrix, which indicated that the T-ZnOw might act as a nucleating agent. Further analysis based on the Hoffman–Lauritzen theory was presented. The results revealed that the surface fold free energy σ e and the absolute values of effective activation energy E α for PA11/T-ZnOw composites were higher than those for neat PA11, which indicated that the addition of T-ZnOw hindered the mobility of chain segments. Both nylon 11 and nylon 11/ T-ZnOw composites exhibited two melting endotherms, while the equilibrium melting point obtained for PA11/T-ZnOw composites was higher than that for neat PA11. [Copyright &y& Elsevier]

Abstract: Nylon 11 samples were filled with conducting polymer, polyaniline (PANI) of two different concentration (1% and 5% w/w) each. The samples in the form of disc containing above concentration were obtained by hot press molding. The structural properties have been investigated using density measurements, wide angle X-ray diffraction (WAXD) and Fourier transform infrared spectroscopy (FTIR) techniques. The morphology of pure and filled samples has been studied using scanning electron microscopy. Glass transition (T g) temperature was determined using dynamic mechanical thermal analyzer (DMTA). The result shows that there is slight crystal modification due to addition of fillers and this effect reduced the crystallinity marginally. [Copyright &y& Elsevier]

Abstract: Different ratios of nylon 11/chitosan blending films were prepared by solution casting method. The strength of the hydrogen bond in the blending films is weakened after addition of chitosan and spherulite growth is restricted as the ratio of chitosan increases. Sea–island morphology could be observed once the concentration of chitosan in the blends was more than 50%. Blending films are characterized by FTIR (Fourier transform infrared spectroscopy), X-ray, and scanning electron microscopy (SEM) and the biodegradability is also investigated. The extent of biodegradability for nylon 11/chitosan blending films is strongly affected by the addition percentage of chitosan. [Copyright &y& Elsevier]

Abstract: A nanoindentation technique was used to investigate mechanical properties (i.e. hardness and modulus) of Nylon 11 (PA11) and its nanocomposites with different clay loading. It has been found that the hardness and modulus of the nanocomposites steadily increase with increasing clay content. With incorporation of 5wt% clay into the PA11 matrix, the hardness and elastic modulus are improved by about 27% and 32%, respectively. The modulus data obtained by nanoindentation are compared with those obtained by tensile testing and dynamic mechanical analysis. The studies prove that nanoindentation is a simple but effective mechanical testing method for the polymer and the nanocomposites. [Copyright &y& Elsevier]

Abstract: Nylon 11/nylon 66 alloys were prepared by in situ polymerization. Analysis of the isothermal crystallization behaviors of nylon 11/nylon 66 alloys was carried out using differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The crystallization kinetics of the primary stage under isothermal conditions could be described by the Avrami equation. The crystal morphology observed by means of polarized optical microscope (POM). In the DSC scan after isothermal crystallization process, the multiple melting behaviors were found and each melting endotherm has a different origin. The real-time XRD measurements confirmed that no crystalline transition existed during the isothermal crystallization process. The multiple endotherms were experimentally evidenced due to melting of the recrystallizated materials or the lamellae produced under different crystallization processes. The equilibrium melting point of samples for isothermal crystallization was also evaluated. [Copyright &y& Elsevier]

Abstract: This study focused on the effect of the maleated ethylene–propylene–diene copolymer (EPDM-MAH) as a compatibilizer on the mechanical properties and morphology of nylon 11/polyethylene (PE) blends. Although the tensile strength and elongation at break of compatibilized nylon 11/PE deviated slightly from the pure nylon 11, the Izod impact strength at room temperature and at low temperature was improved markedly by the addition of 3% compatibilizer. The SEM micrographs of fractured surfaces demonstrated further the enhancement of compatibility between nylon and PE by addition of a reactive compatibilizer. [Copyright &y& Elsevier]

A new kind of polyesteramide copolymer based on ϵ-caprolactone and 11-aminoundecanoic acid has been synthesized by melt polycondensation. The copolymers were characterized by FTIR, 1H-NMR, DSC, and WAXD. With the increase in aminoundecanoic acid content, the melting temperature, heat of fusion, and Td,50% increased accordingly. The thermal degradation of the P(CL/AU)x/y copolymers was studied using FTIR, and TG During thermal degradation, the ester bond decomposes at lower temperature, then the amide bond decomposes at higher temperature. [Copyright &y& Elsevier]

Nylon 11/organoclay nanocomposites have been successfully prepared by melt-compounding. X-ray diffraction and transmission electron microscopy indicate the formation of the exfoliated nanocomposites at low clay concentrations (less than 4 wt%) and a mixture of exfoliated and intercalated nanocomposites at higher clay contents. Thermogravimetric and dynamic mechanical analyses as well as tensile tests show that the degree of dispersion of nanoclay within polymer matrix plays a vital role in property improvement. The thermal stability and mechanical properties of the exfoliated nylon 11/clay nanocomposites (containing lower clay concentrations) are superior to those of the intercalated ones (with higher clay contents), due to the finer dispersion of organoclay among the matrix. [Copyright &y& Elsevier]