Preparation of ZnO nanoparticle‐reinforced polyamide 6 composite by in situ‐coproduced method and their properties

Polyamide 6/ZnO nanocomposites (noted as PA6/ZnO) were prepared by an in situ co‐producing method, during which Zn₂(OH)₂CO₃ decomposed into nano‐ZnO in the process of the opening‐ring polymerization of caprolactam at high temperature. Transmission electron microscopy, X‐ray diffraction, thermogravimetric analysis, and differential scanning calorimetry were used to analyze the size and dispersive properties of nano‐ZnO, the crystallization and melting properties, the thermal properties, and crystal structure of PA6/ZnO composite, respectively. The results showed that the nano‐ZnO derived from Zn₂(OH)₂CO₃ via in situ polymerization of PA6‐ZnO was uniformly dispersed in PA6 matrix. However, the overall nano‐ZnO crystallization rate and crystal size in the PA6 matrix were hindered by the bulky PA6 molecular chains. The mechanical properties were evaluated using universal tensile and impact testing instruments. The results revealed that PA6/ZnO composite with 0.2% nano‐ZnO content possessed excellent tensile strength, enhanced by 75% in comparison with the pure PA6. The nano‐ZnO had little influence on the impact strength of PA6. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 165–170     

Tuning the localization of finely dispersed cellulose nanocrystal in poly (lactic acid)/bio‐polyamide11 blends

A versatile approach to control the localization of cellulose nanocrystal (CNC) in PLA/PA11 blends is presented. A PEO/CNC mixture with a high level of CNC dispersion is prepared through a combination of high pressure homogenization and freeze‐drying. The prepared PEO/CNC mixture is then incorporated into the PLA/PA11 blends using two different strategies. Typically for CNC/PLA/PA11, the CNCs selectively localize in PA11. However, PEO‐coated CNC particles segregate into PLA irrespective of whether the PEO/CNC mixture is premixed with PLA or PA11. It is suggested that a strong interaction between PEO and CNC particles combined with the PLA/PEO miscibility facilitates the localization of PEO‐coated CNC in the PLA. The localization of PEO‐coated CNC in the PLA has no effect on the morphology of the PLA‐5PEO/PA11 with matrix/dispersed phase form. However, 2 wt % PEO‐coated CNC in the co‐continuous (PLA‐5PEO)/PA11 50/50 vol % blend diminishes the phase thickness from 11 ± 1 to 4 ± 1.5 μm. This is attributed to a retarded relaxation of the PLA phase. This work outlines a strategy to control the CNC localization into a given polymeric phase in a binary polymer–polymer mixture. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 576–587     

High‐performance thin film composite membranes with well‐defined poly(dimethylsiloxane)‐b‐poly(ethylene glycol) copolymer additives for CO2 separation

A series of well‐defined diblock copolymers (BCPs) consisting of poly(ethylene glycol) (PEG) and poly(dimethylsiloxane) (PDMS) were synthesized and blended with commercially available PEBAX® 2533 to form the active layer of thin‐film composite (TFC) membranes, via spin‐coating. BCPs with a PEG component ranging from 1 to 10 kDa and a PDMS component ranging from 1 to 10 kDa were synthesized by a facile condensation reaction of hydroxyl terminated PEG and carboxylic acid functionalized PDMS. The BCP/PEBAX® 2533 blends up to 50 wt % on cross‐linked PDMS gutter layers were tested at 35 °C and 350 kPa. TFC membranes containing BCPs of 1 kDa PEG and 1–5 kDa PDMS produced optimal results with CO₂ permeances of approximately 1000 GPU which is an increase up to 250% of the permeance of pure PEBAX® 2533 composite membranes, while maintaining a CO₂/N₂ selectivity of 21. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1500–1511     

Synthesis and characterization of multifunctional polyamide 1 using CO2 and urea via environment‐friendly method

The polyamide 1 (PA1) containing the highest density of hydrogen bond and dipole was synthesized using carbon dioxide (CO₂) and urea as raw materials under supercritical CO₂ condition through environment‐friendly method. Three kinds of molecular weights of PA1 were prepared in this study to satisfy different application areas. The chemical structures of PA1 were characterized comprehensively by means of ¹H and ¹³C NMR, Fourier transform infrared spectroscopy, elements analysis, intrinsic viscosity, and wide angle X‐ray diffraction. The thermal properties and glass transition temperature were measured by thermogravimetric analysis (TGA) and differential scanning calorimetry. The obtained products had intrinsic average molecular weights ranging from 1.29 × 10³ to 1.29 × 10⁴. And the thermal stability and glass transition temperature increased with the increasing of molecular weight. TGA results indicated that the temperatures of 5% and 10% weight loss were 378 and 395 °C, respectively and the maximum decomposition temperatures for the two stages were 416 and 457 °C for the highest molecular weight product. The PA1, a new family member of polyamides, was a potential multifunctional material and found applications as high‐performance material. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 853–859     

Effect of compatibilizer on morphology and properties of HDPE/Nylon 6 blends

The compatibilization effect of linear low‐density polyethylene‐grafted maleic anhydride (LLDPEgMA) and high‐density polyethylene‐grafted maleic anhydride (HDPEgMA) on high‐density polyethylene (HDPE)/polyamide 6 (Nylon 6) blend system is investigated. The morphology of 45 wt %/55 wt % polyethylene/Nylon 6 blends with three compatibilizer compositions (5 wt %, 10 wt %, and 15 wt %) are characterized by atomic force microscopic (AFM) phase imaging. The blend with 5 wt % LLDPEgMA demonstrates a Nylon 6 continuous, HDPE dispersed morphology. Increased amount of LLDPEgMA leads to sharp transition in morphology to HDPE continuous, Nylon 6 dispersed morphology. Whereas, increasing HDPEgMA concentration in the same blends results in gradual morphology transition from Nylon 6 continuous to co‐continuous morphology. The mechanical properties, oxygen permeability, and water vapor permeability are measured on the blends which confirm the morphology and indicate that HDPEgMA is a better compatibilizer than LLDPEgMA for the HDPE/Nylon 6 blend system. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 281–290     

Permeability and thermal properties of PDMS/LDPE multilayer composite membranes

This work reports on the preparation and properties of polydimethylsiloxane (PDMS)/low‐density polyethylene (LDPE) multilayer composite polymer membranes (MCPM) for gas separation applications. The membranes were produced by combining sequential coating with melt‐extrusion/salt leaching techniques. In particular, the gas sorption and permeation properties at different pressure (40–90 psig) and temperature (27–55 °C) are reported with morphology and thermogravimetric properties. The results show that a 20 μm PDMS layer was able to penetrate the microporous LDPE surface layer substrate leading to improved interfacial adhesion. Based on the different gases (CO₂, CH₄, and C₃H₈) solubility, permeability, and diffusivity obtained, these membranes are seen as good candidates for industrial gas separations. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 1045–1052     

Influence of interfaces on the rates of crosslinking in poly(dimethyl siloxane) coatings

We have determined with infrared spectroscopic ellipsometry how the nature of the interface between a thin poly(dimethyl siloxane) (PDMS) coating and its substrate affects the rate of PDMS crosslinking reactions. Reactions between vinyl (? CH?CH₂) end groups on PDMS and silyl (SiH) groups in a crosslinker (hydrosilylation) and between SiH groups and silanol (SiOH) groups, during the so‐called postcure crosslinking stage, have been probed in situ. The overall consumption of SiH follows first‐order reaction kinetics. The first‐order reaction coefficient (k₁) for the hydrosilylation crosslinking reaction is the same for coatings on three different substrates: native oxide on silicon (SiO₂/Si), polystyrene (PS), and poly(ethylene terephthalate). For the slower postcure reactions, however, the rate of SiH consumption depends on the substrate. In 2.5‐μm PDMS coatings on PS, k₁ is about seven times greater than k₁ in the same coating on SiO₂/Si. In PDMS coatings on a PDMS substrate, when the effect of the interface is thus minimal, k₁ is 16 times higher than on SiO₂/Si. The dependence of k₁ on the type of interface is probably the result of the interfacial segregation and complexation of the Pt catalyst for the postcure reactions. We propose that polar surfaces more strongly attract Pt and form complexes that inhibit the postcure reactions. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1421–1431, 2004     

Crystalline structure of polyamide 12 as revealed by solid‐state 13C NMR and synchrotron WAXS and SAXS

The crystalline structure of polyamide‐12 (PA12) was studied by solid‐state ¹³C nuclear magnetic resonance (NMR) as well as by synchrotron wide‐ and small‐angle X‐ray scattering (WAXS and SAXS). Isotropic and oriented PA12 showed different NMR spectra ascribed to γ‐ and γ′‐crystalline modifications, respectively. On the basis of the position of the first diffraction peak, the isotropic γ‐form and the oriented γ′‐form were shown to be with hexagonal crystalline lattice at room temperature. When heated, the two PA12 polymorphs demonstrated different behaviors. Above 140 °C, the isotropic γ‐PA12 partially transformed into α‐modification. No such transition was observed with the oriented γ′‐PA12 phase even after annealing at temperatures close to melting. A γ′–γ transition was observed here only after isotropization by melting point. Various structural parameters were extracted from the WAXS and SAXS patterns and analyzed as a function of temperature and orientation: the degree of crystallinity, the d‐spacings, the Bragg's long spacings, the average thicknesses of the crystalline (l_c) and amorphous (l_a) phases, and the linear crystallinity x_cl within the lamellar stacks. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3720–3733, 2005     

Oxygen barrier,free volume,and blending properties of polyamide 12/poly (vinyl alcohol) blends

Oxygen permeation rates, average volumes of free‐volume‐cavities (V_f), and fractional free volumes (F_v) of polyamide 12 (PA12)/poly(vinyl alcohol) (PVA) (ie, PA12_xPVA⁰⁵_y, PA12_xPVA⁰⁸_y, and PA12_xPVA¹⁴_y) blend films with varying PVA degrees of polymerization reduced to a minimum value when their PVA contents reached a corresponding optimal value, respectively. The minimum oxygen permeation rates, V_f, and F_v values obtained for the optimal PA12_xPVA^z_y blown films were reduced considerably with decreasing PVA degrees of polymerization. Experimental findings from dynamic mechanical analysis, differential scanning calorimetry, wide angle X‐ray diffraction, and Fourier transform infrared spectroscopy of the PA12_xPVA^z_y blend series suggest that PA12 and PVA in PA12_xPVA^z_y are miscible to some extent at the molecular level when their PVA contents are near and less than the corresponding critical values. The considerably enhanced oxygen barrier properties of the PA12_xPVA^z_y blend films with optimized compositions are attributed to the significantly reduced local free volume characteristics.     

Reactive compatibilization of nylon copolymer/EPDM blends: experimental aspects and their comparison with theory

In situ reactive compatibilization was first time applied to a low melting nylon (nylon 6 and 66 copolymer) and EPDM blend system. The effects of in situ compatibilization and concentration of compatibilizer on the morphology and mechanical properties of nylon/EPDM blends have been investigated. The influence of EPM‐g‐MA on the phase morphology was examined by the scanning electron microscopy (SEM) after preferential extraction of the minor phase. The SEM micrographs were quantitatively analyzed for domain size measurements. The compatibilizer concentrations used were 0, 1, 2.5, 5, and 10 wt%. The graft copolymer (nylon‐g‐EPM) formed at the interface showed relatively high emulsifying activity. A maximum phase size reduction was observed when 2.5 wt% of compatibilizer was added to the blend system. This was followed by a leveling‐off at higher loadings indicating interfacial saturation. The conformation of the compatibilizer at the interface was deduced based on the area occupied by the compatibilizer at the blend interface. The experimental compatibilization results were compared with theoretical predictions of Noolandi and Hong. It was concluded that the molecular state of compatibilizer at interface changes with concentration. The in situ compatibilized blends showed considerable improvement in mechanical properties. Measurement of tensile properties shows increased elongation as well as enhanced modulus and strength up on compatibilization. At higher concentrations of compatibilizer, a leveling‐off of the tensile properties was observed. A good correlation has been observed between the mechanical properties and morphological parameters. Copyright © 2007 John Wiley & Sons, Ltd.     

Foaming behavior of polypropylene/polystyrene blends enhanced by improved interfacial compatibility

A series of polypropylene (PP)/polystyrene (PS) blends were prepared by solvent blending with PS‐grafted PP copolymers (PP‐g‐PS) having different PS graft chain length as compatibilizers. The interfacial compatibility was significantly improved with increasing PS graft chain length until the interface was saturated at PS graft chain length being 3.29 × 10³ g/mol. The blends were foamed by using pressure‐quenching process and supercritical CO₂ as the blowing agent. The cell preferentially formed at compatibilized interface because of low energy barrier for nucleation. Combining with the increased interfacial area, the compatibilized interface lead to the foams with increased cell density compared to the uncompatibilized one. The increase in interfacial compatibility also decreased the escape of gas, held more gas for cell growth, and facilitated the increase in expansion ratio of PP/PS blend foams. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1641–1651, 2008     

The effect of compatibilization and rheological properties of polystyrene and poly(dimethylsiloxane) on phase structure of polystyrene/poly(dimethylsiloxane) blends

The compatibilization effect of polystyrene (PS)‐poly(dimethylsiloxane) (PDMS) diblock copolymer (PS‐b‐PDMS) and the effect of rheological properties of PS and PDMS on phase structure of PS/PDMS blends were investigated using a selective extraction technique and scanning electron microscopy (SEM). The dual‐phase continuity of PS/PDMS blends takes place in a wide composition range. The formation and the onset of a cocontinuous phase structure largely depend on blend composition, viscosity ratio of the constituent components, and addition of diblock copolymers. The width of the concentration region of the cocontinuous structure is narrowed with increasing the viscosity ratio of the blends and in the presence of the small amount diblock copolymers. Quiescent annealing shifts the onset values of continuity. The experimental results are compared with the volume fraction of phase inversion calculated with various theoretical models, but none of the models can account quantitatively for the observed data. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 898–913, 2004     

Structure and optical properties of transparent polyamide 6 containing lithium bromide

We investigated the effects of lithium bromide (LiBr) on the structure and properties of polyamide 6 (PA6). The strong ion–dipole interactions between lithium cations and the amide groups in PA6 greatly increased the glass transition temperature (T_g) and retarded the crystallization rate of PA6. As a result, compression-molded PA6 blends were highly transparent and had high T_g values. The rheological terminal region was obvious in the blends because the ion–dipole interactions weakened at high temperatures. This indicates that the melt processability was barely affected by LiBr. We also evaluated the optical anisotropy of the polymer to determine its suitability as a functional optical film. We found that hot-stretched blend films had large positive orientation birefringence with significantly weak wavelength dispersion, which can be attributed to the enhanced anisotropic polarizability of PA6. We also found that the stress-optical coefficient in the glassy region decreased with increasing LiBr content. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 1513–1520     

Atomic force microscopy study on blend morphology and clay dispersion in polyamide‐6/polypropylene/organoclay systems

The phase structure and clay dispersion in polyamide‐6(PA6)/polypropylene(PP)/organoclay (70/30/4) systems with and without an additional 5 parts of maleated polypropylene (MAH‐g‐PP) as a compatibilizer were studied with atomic force microscopy (AFM). AFM scans were taken from the polished surface of specimens that were chemically and physically etched with formic acid and argon ion bombardment, respectively. The latter technique proved to be very sensitive to the blend morphology, as PP was far more resistant to ion bombardment than PA6. In the absence of the MAH‐g‐PP compatibilizer, the organoclay is located in the PA6 phase; this finding is in line with transmission electron microscopic results. Further, the PP is coarsely dispersed in PA6 and the adhesion between PA6 and PP is poor. The addition of MAH‐g‐PP resulted in a markedly finer PP dispersion and good interfacial bonding between PA6 and PP. In this blend, the organoclay was likely dispersed in the PA6‐grafted PP phase. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43:1198–1204, 2005     

Block copolymer compatibilizers for polystyrene/poly(dimethylsiloxane) blends

Symmetric polystyrene (PS)–poly(dimethylsiloxane) (PDMS) diblock copolymers were mixed into a 20% dispersion of PDMS in PS. The effect of adding the block copolymer on the blend morphology was examined as a function of the block copolymer molecular weight (M_n,bcp), concentration, and viscosity ratio (η_r). When blended together with the PS and PDMS homopolymers, most of the block copolymer appeared as micelles in the PS matrix. Even when the copolymer was preblended into the PDMS dispersed phase, block copolymer micelles in the PS matrix phase were observed with transmission electron microscopy after mixing. Adding 16 kg/mol PS–PDMS block copolymer dramatically reduced the PDMS particle size, but the morphology, as examined by scanning electron microscopy, was unstable upon thermal annealing. Adding 156 kg/mol block copolymer yielded particle sizes similar to those of blends with 40 or 83 kg/mol block copolymers, but only blends with 83 kg/mol block copolymer were stable after annealing. For a given value of M_n,bcp, a minimum PDMS particle size was observed when η_r ～ 1. When η_r = 2.6, thermally stable, submicrometer particles as small as 0.6 μm were observed after the addition of only 3% PS–PDMS diblock (number‐average molecular weight = 83 kg/mol) to the blend. As little as 1% 83 kg/mol block copolymer was sufficient to stabilize a 20% dispersion of 1.1‐μm PDMS particles in PS. Droplet size reduction was attributed to the prevention of coalescence caused by small amounts of block copolymer at the interface. The conditions under which block copolymer interfacial adsorption and interpenetration were facilitated were explained with Leibler's brush theory. © 2002 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 40: 346–357, 2002; DOI 10.1002/polb.10098     

One‐pot synthesis of polyamide 12,T–polyamide‐6 block copolymers

Polyamide 12,T–polyamide‐6 (PA‐12,T–PA‐6) block copolymers were synthesized by anionic polymerization of caprolactam using a PA‐12,T macrocoinitiator (McI). PA‐12,T McI and its precursors are soluble in molten caprolactam allowing for both the McI step‐growth polymerization and anionic polymerization to be performed in one‐pot. It was found that the competing reaction rates of caprolactam ring‐opening polymerization and McI transamidation are both deterred by a common ion effect using CaCl₂ and soluble materials were obtained using >1 mol % CaCl₂. Without CaCl₂, the reaction mixture solidifies in less than 30 s and produces crosslinked materials. To understand this effect, PA‐12,T McI reactions with caprolactam were performed with 1–10 mol % CaCl₂, and polymer structures were characterized using ¹³C NMR and dilute solution viscometry. These data were then correlated with unique thermal properties and swelling behavior of the block copolymers. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Stress–strain behavior of low‐density polyethylene/poly(methyl methacrylate) blends with modulated interfaces with a hydrogenated polybutadiene‐block‐poly(methyl methacrylate) diblock copolymer

The stress–strain diagrams and ultimate tensile properties of uncompatibilized and compatibilized hydrogenated polybutadiene‐block‐poly(methyl methacrylate) (HPB‐b‐PMMA) blends with 20 wt % poly(methyl methacrylate) (PMMA) droplets dispersed in a low‐density polyethylene (LDPE) matrix were studied. The HPB‐b‐PMMA pure diblock copolymer was prepared via controlled living anionic polymerization. Four copolymers, in terms of the molecular weights of the hydrogenated polybutadiene (HPB) and PMMA sequences (22,000–12,000, 63,300–31,700, 49,500–53,500, and 27,700–67,800), were used. We demonstrated with the stress–strain diagrams, in combination with scanning electron microscopy observations of deformed specimens, that the interfacial adhesion had a predominant role in determining the mechanism and extent of blend deformation. The debonding of PMMA particles from the LDPE matrix was clearly observed in the compatibilized blends in which the copolymer was not efficiently located at the interface. The best HPB‐b‐PMMA copolymer, resulting in the maximum improvement of the tensile properties of the compatibilized blend, had a PMMA sequence that was approximately half that of the HPB block. Because of the much higher interactions encountered in the PMMA phase in comparison with those in HPB (LDPE), a shorter sequence of PMMA (with respect to HPB but longer than the critical molecular weight for entanglement) was sufficient to favor a quantitative location of the copolymer at the LDPE/PMMA interface. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 22–34, 2005     

Modulated release from implantable ocular silicone oil tamponade drug reservoirs

Complicated cases of retinal detachment can be treated with silicone oil tamponades. There is the potential for silicone oil tamponades to have adjunctive drug releasing behaviour within the eye, however the lipophilic nature of silicone oil limits the number of drugs that are suitable, and drug release from the hydrophobic reservoir is uncontrolled. Here, a radiometric technique was developed to accurately measure drug solubility in silicone oil and measure release into culture media. All‐trans retinoic acid (atRA), a lipophilic drug known to act as an anti‐proliferative within the eye, was used throughout this work. Chain‐end modification of polydimethylsiloxane with atRA produced a polydimethylsiloxane retinoate (PDMS‐atRA), which was used as an additive to silicone oil to modify the solvent environment within the silicone oil and the distribution coefficient. Blends of PDMS‐atRA and silicone oil containing different concentrations of free atRA were produced. The presence of PDMS‐atRA in silicone oil had a positive effect on atRA solubility and the longevity of release in vitro. The drug release period was independent of atRA starting concentration and dependent on the PDMS‐atRA concentration in the blend. A clinically relevant release period of atRA over 7 weeks from a silicone oil blend with PDMS‐atRA was observed. © 2018 The Authors. Journal of Polymer Science Part A: Polymer Chemistry Published by Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 938–946     

Effect of Structure of Functionalizing Molecules on the Inter‐Macromolecular Reactions and Blending of Poly(ethylene‐co‐propylene) (EPM) with Poly(6‐aminohexanoic Acid) (PA6)

Two different functionalizing systems, i.e., monohexadecyl maleate (= hexadecyl hydrogen (2Z)‐but‐2‐enedioate) in the presence of dicumyl peroxide (= bis(1‐methyl‐1‐phenylethyl) peroxide) or 4‐carboxybenzenesulfonazide (= 4‐(azidosulfonyl)benzoic acid), were used in distinct experiments to perform in a one‐step procedure the formation of a EPM–PA6 graft copolymer, necessary to obtain a compatibilized blend, from a molten mixture of ethylene–propylene copolymer (EPM) and polyamide 6 (PA6). The characterization of the graft polymer by selective solvent extraction of the blends and the subsequent IR and NMR analysis of the various fractions established the occurrence of functionalization reactions preferentially onto the polyolefin with both reagents. Also the formation in good yield of graft copolymers at the phases interface was observed. Moreover, the morphology and thermal characterizations of the blends by means of SEM and DSC analyses were used to evaluate the compatibilization extent in comparison with blends obtained by the conventional two‐step procedure or by the one‐step procedure with commercial maleic acid derivatives.     

Processing polyamides with superheated water

Superheated water (shH₂O) is investigated as a process aid in conventional aliphatic polyamide (PA) systems. The polymers investigated include PA 6 (PA6), PA 6,6 (PA66), PA 6,12 (PA612), and PA 12 (PA12). It is shown that the PA melting and crystallization temperatures are significantly reduced when exposed to shH₂O. For example, the melting temperature of PA6 is depressed from 206 to 153 °C in the presence of shH₂O. A relationship between amide group density and thermal transition temperature reduction is observed. Processing these materials in shH₂O has led to a variety of materials ranging from low‐density foams to higher density locally anisotropic foamed morphologies. In situ observations of PAs melting in the presence of shH₂O are performed using a specially designed reactor. Results from these experiments are used to estimate the diffusion coefficient of shH₂O in PA6. Finally, low‐temperature extrusion is performed with PA6 and shH₂O at temperatures as low as 180 °C and mixture viscosity is estimated. A 20‐fold depression in the melt viscosity of PA6 is observed at 240 °C with shH₂O. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 803–813