Binary alloys of nylon 6 and ethylene-methacrylic acid copolymers: Morphological,thermal and mechanical analysis

The morphology and mechanical properties of binary blends of nylon 6 (N6), as the major component, and ethylene-methacrylic acid copolymers (E/MAA), as the minor component, have been analyzed. It was found that the methacrylic acid content of the copolymer used as the second component has a profound effect upon the properties of the resulting blends. In particular, with increasing methacrylic acid content, the size of the domains of the E/MAA dispersed phase in the N6 matrix decreased in a regular fashion while the ultimate tensile properties increased regularly. This behavior has been attributed to a series of chemical and physico-chemical interactions taking place between the two components. The interactions are due to the presence of the acid functionality on the copolymer and do not occur when this functionality is absent. Chemical analysis of the blends was performed to confirm that chemical modification took place during the blending process.     

Microscopic morphology,rheological behavior,and mechanical properties of polymers: Recycled acrylonitrile-butadiene-styrene/polybutylene terephthalate blends

In this study, styrene-acrylonitrile-glycidyl methacrylate (SAG) series copolymers were specially designed for producing the recycled acrylonitrile-butadiene-styrene (rABS)/poly(butylene terephthalate) (PBT)/SAG blends, which were prepared through the process of continuous melt blending and batch feeding. The effects of viscosity composition, SAG chemical composition, and SAG content on the morphology, and rheological and mechanical properties of the blends have been investigated. As demonstrated by morphological observation, the variety of viscosity composition of the blends affects the size of dispersed PBT droplets. Moreover, high viscosity of rABS matrix seems to facilitate the formation of smaller dispersed phase size of blends. Various SAG chemical compositions have different stabilities on the morphology of the blends, which affects the deformation, fragmentation, and coalescence of dispersed phase droplets. In addition, a finer phase morphology can be achieved when the density distribution of epoxy group is optimal in SAG copolymer. Rheological characterization manifested that the rheological properties of the blends depends strongly on its composition and structure, while the crosslinking degree is associated with the concentration of reactive groups and extent of reaction. Thereby, the rheological behavior of the blends during processing can be controlled by changing the reactive sequence and adding the quantity of epoxy group. The test on mechanical properties verified that a recycled product with excellent performance can be obtained by altering processing methods and the blends formula, which may be further applied to the 3D printing materials required by fused deposition modeling technology. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48310.     

Melt-spinning dynamics and rheological properties of nylon 6

Basic studies of the melt-spinning dynamics and rheological properties of a nylon 6 polymer are described. The magnitude of the force components on the spinline has been analyzed with special reference to the drag and rheological forces. Spinline deformation has been investigated for spinning through ambient air and through an isothermal chamber. Both sets of experiments are interpreted using an elongational viscosity. Non-Newtonian viscosity was measured at 230°, 250°, and 270°C in a Weissenberg rheogoniometer and an Instron capillary rheometer. The principal normal stress difference was measured in the former instrument. The rheological properties are interpreted in terms of the theory of viscoelastic fluid behavior. The isothermal melt-spinning experiments were also interpreted in terms of the theory of viscoelastic fluids, and attempts were made to understand the spinning results in terms of basic rheological properties.     

Morphological properties,rheological behaviors,and phase interaction of nylon 11/polypropylene blends by in situ reactive compatibilization and dispersion through polyhydroxybutyrate

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.     

Effect of titanate coupling agent on the mechanical,thermal, dielectric,rheological, and morphological properties of filled nylon 6

Fillers are used along with various commodity as well as engineering polymers to improve the properties of polymers. The performance of filled polymers is generally decided on the basis of the interface attraction of filler and polymers. Fillers of widely varying particle size and surface characteristics are responsive to the interfacial interactions with polymers. The present study deals with the effect of a coupling agent, tetra isopropyl titanate (TPT), on the properties of flyash filled nylon 6. It is observed that tensile strength, impact strength, and heat distortion temperature improved with the addition of TPT as compared to without the coupling agent filled nylon 6. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 266–272, 2006     

Tremolite-reinforced nylon 66 composites: Mechanical and rheological properties

The reinforcement effect of an acicular inorganic filler, tremolite, on nylon 66 was studied. The mechanical properties of tremolite-filled nylon 66 composites and the effect of the filler particle size on them were obtained. The dynamic mechanical properties and rheological properties of the composites were measured. Two treatments, silane and unsaturated polyester, were used to improve the interface between tremolite and the nylon matrix. The morphologies of the composites were investigated using SEM. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 589–598, 1998     

Morphological,thermal, rheological,and mechanical properties of PP/EVOH blends compatibilized with PP‐g‐IA

We prepared some blends of polypropylene (PP) and ethylene vinyl alcohol (EVOH) with and without a compatibilizer. As a new compatibilizer, we synthesized polypropylene grafted with itaconic acid (PP‐g‐IA) using Brabender mixing system. We investigated the morphological, thermal, rheological, and mechanical properties of a compatibilized blends (PP/EVOH/PP‐g‐IA) and not compatibilized blends (PP/EVOH). Our experiments showed that carboxylic acid groups in PP‐g‐IA and hydroxyl group in EVOH formed strong in situ hydrogen bond in the compatibilized blends, resulting in better morphological and mechanical properties of the compatibilized blends than those of not compatibilized blends. POLYM. ENG. SCI., 56:1240–1247, 2016. © 2016 Society of Plastics Engineers     

Morphological,thermal, and mechanical properties of polypropylene/polycarbonate blend

This work deals with the effect of compatibilizer on the morphological, thermal, rheological, and mechanical properties of polypropylene/polycarbonate (PP/ PC) blends. The blends, containing between 0 to 30 vol % of polycarbonate and a compatibilizer, were prepared by means of a twin-screw extruder. The compatibilizer was produced by grafting glycidyl methacrylate (GMA) onto polypropylene in the molten state. Blend morphologies were controlled by adding PP-g-GMA as compatibilizer during melt processing, thus changing dispersion and interfacial adhesion of the polycarbonate phase. With PP-g-GMA, volume fractions increased from 2.5 to 20, and much finer dispersions of discrete polycarbonate phase with average domain sizes decreased from 35 to 3 μm were obtained. The WAXD spectra showed that the crystal structure of neat PP was different from that in blends. The DSC results suggested that the degree of crystallization of PP in blends decreased as PC content and compatibilizer increased. The mechanical properties significantly changed after addition of PP-g-GMA. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 1857–1863, 1997     

Morphological,rheological and thermal studies in melt processed compatibilized PA6/ABS/clay nanocomposites

Multicomponent compatibilized blends of polyamide 6 (PA6) and styrene-butadiene-acrylonitrile (ABS) with co-continuous morphology are among commercial alloys with an interesting combination of properties. To further enhance the properties different amounts of nanoclay were incorporated into these blends through a one step melt mixing process. The effect of nanoclay addition on rheological, thermal stability, crystallization and morphological properties of the nanocomposites were investigated and compared with those of the neat blends. The nanoscale dispersion of the clay layers in the blends were confirmed through X-ray diffraction and transmission electron microscopy methods. Rheological investigation indicated an increased viscosity and melt elasticity for the nanocomposite systems. The viscosity of nanocomposites followed a shear thinning flow behavior and decreased with increasing shear rates. The changes in the rheological properties were accompanied by refinement of the co-continuous morphology. For thermal degradation under N₂ atmosphere, the onset and maximum of degradation temperatures for the nanocomposites were as high as the neat blends, while significant improvement in thermal stability (about 60 °C by 3 wt% clay addition) was observed in the air environment. In addition agglomerated clay particles did not significantly affect thermal stability of the polymer matrix. Non-isothermal crystallization results indicated that the clay layers had a retarding effect on the crystal growth rate and facilitated the formation of α crystalline form. In addition no nucleation effect was observed during the crystallization process due to incorporation of nanoclay into the blends.     

Flame retardancy,thermal, rheological,and mechanical properties of polycarbonate/polysilsesquioxane system

The polymethylphenylsilsesquioxane (PMPSQ) microspheres were used as an additive for the injection‐molding of polycarbonate (PC) in order to obtain a flame retardant polymer and to damage the other properties of PC as low as possible. The results showed that PMPSQ microspheres were a kind of effective flame retardant by the LOI test and the flame retardancy of PC increased with the increase of PMPSQ content. Thermogravimetric analysis suggested that the PMPSQ could induce crosslinking reactions and accelerate the thermal degradation of PC, sequentially promote the formation of the residue char during degradation. Differential scanning calorimetry measurement showed that the glass transition temperature of PC/PMPSQ system was decreased with the increase of PMPSQ content, which maybe caused by the enlarged free volume of PC‐rich phase. The rheological behaviors including dynamic and steady modes, combined with the analysis of scanning electron microscopy photographs, exhibited that the dispersion and compatibility of PMPSQ in the PC matrix decreased the viscosity of the systems and the addition of PMPSQ microspheres improved the processability of PC, but still there exist aggregation of PMPSQ microspheres in PC matrix, which gave a higher impact strength but a lower flexural modulus and elongation at break than pure PC. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Alteration of the mechanical and thermal properties of nylon 6/nylon 6,6 blends by nanoclay

Nylon 6 [N(6)], nylon 6,6 [N(6,6)], and their blends at different clay loadings were prepared. The mix was melted and injected into strip‐shaped samples. Mechanical and thermal analyses were performed to investigate the effect of blending and the incorporated clay on the mechanical and thermal properties. Enhancements in the Young's modulus and hardness were obtained for all of the nanocomposites, with a 55% increase in Young's modulus after the addition of 6 wt % nanoclay, although the improvement in tensile strength depended on the blend ratio, with greatest effects on the 50% N(6)/50% N(6,6) blend with increases of 44 and 59% for 2 and 4% clay loadings, respectively. Thermogravimetric analysis showed an enhancement in the thermal properties in the 50% N(6)/50% N(6,6) blend at 2% clay loading, and the blend exhibited ductile behavior at this loading. Increases in the crystallization peak temperatures of 10–15° in N(6,6) and the two blends 30% N(6)/70% N(6,6) and 50% N(6)/50% N(6,6) were observed after the addition of the clay. The nanoclay enhanced the γ‐/β‐form crystals in N(6) and N(6,6) neat polymers and also in the blends. Fourier transform infrared spectroscopy FT‐IR revealed the formation of hydrogen bonding and the possible formation of ionic bonds between the polymers and the nanoclay, which resulted in enhancements in the mechanical properties of the blends. The distribution of the nanoclay in the blend was well dispersed, as shown by X‐ray diffraction analysis. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Morphological, structural and rheological properties of beta-cyclodextrin based polypseudorotaxane gels

Supramolecular self-assembled gels of polypseudorotaxane (PPR) were made through sequential inclusion complexations between beta-cyclodextrin (β-CD) and reverse Pluronic^® (RPL, or PPG-PEG-PPG). This study aimed to disclose the differences in morphological, structural and rheological properties of the PPR gels made in citric acid and other conditions. β-CD/RPL mixture in citric acid solution incubated at 25 °C (β-CD/RPL-C-25) had the most homogeneous, fine and continuous structure, the lowest crystallite size, and the highest gel strength and thixotropy. It was hypothesized that the citric acid partially interfered with the crystal growth of PPR, and thus led to high degree of crosslinking which explained its largest gel strength and thixotropy. β-CD/RPL mixtures in water incubated at 65 °C (β-CD/RPL-W-65) underwent PPR rearrangement, resulting in larger crystallites and a more integrate net-like structure, therefore yielding higher gel strength as compared with β-CD/RPL mixture in water incubated at 25 °C.     

Morphological changes in nylon-6/acrylonitrile-butadiene-styrene reactive blend

The morphological changes of blends of nylon-6 and acrylonitrile-butadiene-styrene (ABS) with reactive compatibilizer [poly(N-phenylmaleimide-styrene-maleic anhydride)] as a function of viscosity ratio of the components, concentration of compatibilizer, and the feed rate have been studied using an intermeshing corotating twin screw extruder. The occurrence of reaction between the amine end group of nylon-6 and maleic anhydride of compatibilizer during melt blending was identified by the solvent extraction and infrared spectroscopy study. It was found that the minimum dispersed phase size occurred at the viscosity ratio (p) = 0.75. Dispersed phase size was decreased significantly by the addition of compatibilizer and tended to equilibrate at about 15 wt % compatibilizer based on the amount of nylon-6. It was observed that the morphology was strongly dependent on the feed rate. The presence of maximum dispersed phase size was observed as a function of feed rate. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 1595–1604, 1997     

Morphology,thermal, and rheological behavior of nylon 11/multi‐walled carbon nanotube nanocomposites prepared by melt compounding

Nylon 11 (PA11) nanocomposites with different loadings of multi‐walled carbon nanotubes (MWNTs) were prepared by melt compounding. Scanning electron microscopy images on the fracture surfaces of the composites showed a uniform dispersion of MWNTs throughout the matrix. The presence of the MWNTs significantly improved the thermal stability and enhanced the storage modulus (G′) of the polymer matrix. Melt rheology studies showed that, compared with neat PA11, the incorporation of MWNT into the matrix resulted in higher complex viscosities (|η*|), storage modulus (G′), loss modulus (G″), and lower loss factor (tanδ). PA11 and its nanocomposites containing less than 1 wt% MWNTs showed similar frequency dependencies and reached a Newtonian plateau at low frequencies. For the nanocomposite with 2 wt% MWNTs, the regional network was destroyed and the orientation of the MWNTs during shearing exhibited a very strong shear thinning effect. The complex viscosities (|η*|) of the nanocomposites are larger than that of neat PA11 and decreased with increasing the temperature. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

Morphology,thermal and mechanical properties of nylon 12/organoclay nanocomposites prepared by melt compounding

Nylon 12 (PA12) nanocomposites with different organoclay loadings were successfully prepared by melt compounding. X‐ray diffraction indicated the dominance of the exfoliated clay morphology throughout the matrix after mixing in a Brabender twin‐screw extruder, in accordance with transmission electron microscopy observations. Thermogravimetric analysis showed that the thermal stability of the PA12 matrix was improved by about 20 °C on incorporation of only 5 wt% clay. Tensile and nanoindentation tests indicated that the elastic modulus and the hardness steadily increased by about 52 % and 67 %, respectively, with a clay concentration up to 5 wt%, while improvements in tensile strength were limited. Impact strength decreased linearly by about 25 % as the clay loading increased (up to 5 wt%), indicating an embrittlement due to clay addition, as evidenced by SEM observation on the fracture surfaces. The embrittling effect may be due to the weak interfacial adhesion between the clay platelets and the polymer matrix. Copyright © 2004 Society of Chemical Industry     

乙烯-乙酸乙烯酯共聚物/聚乙烯热塑性硫化胶的形态结构及流变性能

使用双转子密炼技术制备了具有双连续相结构的乙烯-乙酸乙烯酯共聚物(EVA)/聚乙烯(PE)的热塑性聚烯烃(EVA/PE-TPO)和热塑性硫化胶(EVA/PE-TPV)材料,并利用扫描电子显微镜、Han曲线和vGP曲线对二者的相形貌进行了分析和表征。动态流变行为的结果表明,在低频区,EVA含量对EVA/PE-TPO材料体系的储能模量(G′)和复数黏度的影响均大于EVA/PE-TPV体系;在高频区,组成相同的两种体系的G′相近。当两相的组成比例相同时,时温等效原理适用于210℃以下的EVA/PE-TPV体系。修正Palierne模型对双连续相结构EVA/PE-TPV材料的线性黏弹性的拟合程度不高。     

Effects of coupling agents on the rheological behavior and physical/mechanical properties of filled nylon 6

An investigation was made on the rheological behavior and physical/mechanical properties of highly filled nylon 6 composites with and without a coupling agent. As fillers, calcium carbonate and calcium silicate were used, and, as coupling agent, two silanes (Union Carbide, A1100 and Y9187) and two titanates (Kenrich Petrochemicals, KR-44 and KR-138) were used. It was found that all the coupling agents used increased the viscosities of the nylon/CaCO₃ system. However, the effect of the coupling agents on the viscosity of the nylon/CaSiO₃ system seems quite complex; namely, the titanate KR-44 decreased the melt viscosity of the nylon/CaSiO₃ composite, whereas the titanate KR-138S and the silane Y9187 increased it. In general, the effectiveness of the coupling agents in improving the physical/mechanical properties of the nylon/CaCO₃ and nylon/CaSiO₃ composites was marginal. A considerable decrease in glass transition was observed upon exposure of all samples to water, regardless of the type of filler and coupling agent.     

NBR/三元尼龙/二元尼龙三元共混型热塑性弹性体制备工艺与性能的研究

在开炼机上用动态硫化法制备了NBR／三元尼龙／二元尼龙三元共混型热塑性弹性体。研究了共混工艺、返炼次数、动态硫化温度、二元尼龙用量等因素对材料性能的影响。NBR／三元尼龙／二元尼龙三元共混型热塑性弹性体不仅具有优异的耐溶剂性，而且其物理性能也较好。     

Mechanical and thermal properties of dimer acid based nylon 636/Nylon 66 copolymers

Dimer acid (DA)‐based nylon 636/nylon 66 copolymers were synthesized by in situ polymerization. The effects of incorporating nylon 66 on the mechanical and thermal properties were characterized by means of intrinsic viscosity determination, attenuated total reflection (ATR)–Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), differential scanning calorimetry, thermogravimetric analysis, and mechanical testing. The results show that the intrinsic viscosity of the copolymers ranged from 1.0 to 2.1 dL/g, depending on the content of nylon 66. The incorporation of nylon 66 into DA‐based nylon 636 had no significant effect on the values of the glass‐transition temperature, melting temperature, temperature at 50% weight loss, or temperature at the maximum rate of decomposition, but the crystallization temperature, crystallinity degree, and extrapolated onset temperature increased. ATR–FTIR spectroscopy and XRD demonstrated that with increasing nylon 66 mass, the content of α‐ and β‐crystal forms would increase accordingly. The mechanical test data revealed that with increasing nylon 66 concentration, the tensile strength of the copolymers increased, and the flexural strength and flexural modulus first increased and then decreased. However, the notched Izod impact strength decreased. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 39845.