Blending Protocol Research Articles

Laboratory Study on Influence of Blending Conditions on Chemo-Thermal Characteristics of Lignin-Modified Bitumen

Environmental approaches in the asphalt industry have focused on utilizing waste materials as modifiers. Lignin is a high-potential bitumen modifier due to its characteristics; however, the blending process with bitumen is critical. This study investigates the chemo-thermal characteristics of lignin-modified bitumen under two different blending protocols, including a mechanical and high-shear mixer to evaluate its performance as a modifier. According to the protocols, 5, 10, and 20% of Kraft lignin was added to a PG 58S−28 bitumen. The samples were subjected to analysis using Brookfield Rotational Viscosity (BRV), Dynamic Shear Rheometer (DSR), Fourier-Transform Infrared Spectroscopy (FTIR), Environmental Scanning Electron Microscopy (ESEM), Thermogravimetric Analysis (TGA), and Differential Scanning Calorimetry (DSC) tests. The BRV and DSR test results indicate a remarkable alteration in the rheological properties of lignin-modified bitumen under blending conditions. The FTIR analysis indicated that Kraft lignin did not produce new functional groups. The fibril structures of the bitumens are affected by Kraft lignin content and blending conditions due to ESEM. The Kraft lignin and blending conditions influence the thermal behavior of bitumen. The findings highlight Kraft lignin’s potential as a bitumen modifier, and the fact that its characteristics are influenced by the blending protocol and Kraft lignin content.

Development of an improved standard reference material for folate vitamers in human serum.

The US National Institute of Standards and Technology (NIST) developed a Standard Reference Material® (SRM®) 3949 Folate Vitamers in Frozen Human Serum to replace SRM 1955 Homocysteine and Folate in Human Serum. The presence of increased endogenous levels of folic acid and 5-methyltetrahydrofolate (5mTHF) in SRM 3949, enhanced folate stability via addition of ascorbic acid, and inclusion of values for additional minor folates are improvements over SRM 1955 that should better serve the clinical folate measurement community. The new SRM contains folates at three levels. To produce SRM 3949, pilot sera were collected from 15 individual donors, 5 of whom were given a 400-µg folic acid supplement 1h prior to blood draw to increase serum levels of 5mTHF and folic acid for the high-level material. To stabilize the folates, 0.5% (mass concentration) ascorbic acid was added as soon as possible after preparation of serum. These pilot sera were screened for five folates plus the pyrazino-s-triazine derivative of 4-α-hydroxy-5-methyltetrahydrofolate (MeFox) at the US Centers for Disease Control and Prevention (CDC) by isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS). Based on these results, a blending protocol was specified to obtain the three desired folate concentrations for SRM 3949. ID-LC-MS/MS analysis at the CDC and NIST was utilized to assign values for folic acid and 5mTHF, as well as several minor folates.

Image quality enhancement of CT hepatic portal venography using dual energy blending with computer determined parameters.

Previous studies have shown that using some post-processing methods, such as nonlinear-blending and linear blending techniques, has potential to improve dual-energy computed (DECT) image quality. To improve DECT image quality of hepatic portal venography (CTPV) using a new non-linear blending method with computer-determined parameters, and to compare the results to additional linear and non-linear blending techniques. DECT images of 60 patients who were clinically diagnosed with liver cirrhosis were selected and studied. Dual-energy scanning (80 kVp and Sn140 kVp) of CTPV was utilized in the portal venous phase through a dual-source CT scanner. For image processing, four protocols were utilized including linear blending with a weighing factor of 0.3 (protocol A) and 1.0 (protocol B), non-linear blending with fixed blending width of 200 HU and set blending center of 150HU (protocol C), and computer-based blending (protocol D). Several image quality indicators, including signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and contrast of hepatic portal vein and hepatic parenchyma, were evaluated using the paired-sample t-test. A 5-grade scale scoring system was also utilized for subjective analysis. SNR of protocols A-D were 9.1±2.1, 12.1±3.0, 11.6±2.8 and 14.4±3.2, respectively. CNR of protocols A-D were 4.6±1.3, 8.0±2.3, 7.0±2.0 and 9.8±2.4, respectively. The contrast of protocols A-D were 37.7±11.6, 91.9±21.0, 66.2±19.0 and 107.7±21.3, respectively. The differences between protocol D and other three protocols were significant (P < 0.01). In subjective evaluation, the modes of protocols A, B, C, and D were rated poor, good, generally acceptable, and excellent, respectively. The non-linear blending technique of protocol D with computer-determined blending parameters can help improve imaging quality of CTPV and contribute to a diagnosis of liver disease.

Influence of blending protocol on the mechanical, rheological, and electromagnetic properties of PC/ABS/ABS‐g‐MAH blend‐based MWCNT nanocomposites

AbstractPolycarbonate (PC)/acrylonitrile‐butadiene‐styrene copolymer (ABS) blend‐based multi‐wall carbon nanotubes (MWCNT) nanocomposites is an attractive alternative for the manufacture of electronics housing as it can have the mechanical and electromagnetic properties required for this application. The preferred location of MWCNT in PC/ABS blend is an important parameter to obtain better mechanical and electromagnetic properties. In this way, three different blending protocols (BP) were used to obtain PC/ABS/maleic anhydride‐grafted ABS (ABS‐g‐MAH) (85/10/5) blend‐based MWCNT nanocomposites with the addition of 0.5 and 1 wt% of MWCNT in a twin‐screw extruder. Specimens were evaluated by thermal (thermogravimetric analysis—TGA and differential scanning calorimetry—DSC), mechanical (Izod impact strength and tensile tests), dynamic mechanical analysis (DMA), electrical, and rheological properties, which were correlated with the nanocomposites morphology evaluated by high‐resolution scanning electron microscopy. The BP associated with the addition of a compatibilizer agent influenced the MWCNT distribution and location in the polymeric matrix. The one‐step extrusion process results in MWCNT mostly at the interface of the PC/ABS blend and agglomerates, leading to lower mechanical and thermal properties. The BP in which a PC/MWCNT masterbatch was first prepared and then diluted in ABS and ABS‐g‐MAH achieves the higher mechanical properties, increasing Young's modulus and the ultimate tensile strength. The third BP in which MWCNT was added in a second step in the blend already processed resulted in a homogeneous dispersion of MWCNT on both phases and a lower electrical resistivity.

Effect of Waste Polyethylene and Wax-Based Additives on Bitumen Performance.

Over the last years, the replacement of traditional polymer modifiers with waste plastics has attracted increasing interest. The implementation of such technology would allow a drastic reduction of both production cost and landfill disposal of wastes. Among all, polyethylene-based plastics have been proved suitable for this purpose. The research activities presented in this paper aim to assess the synergistic effect of polyethylene and Fischer–Tropsch waxes on the viscoelastic properties and performance of the bitumen. In order to reduce the blending time, waxes, and polyethylene need to be added simultaneously. In fact, the presence of the waxes reduces the polarity of the bitumen matrix and increases the affinity with the polymer promoting its dispersion. Results demonstrate that the chain length of the waxes, the form of the added waste polyethylene, and the blending protocol have critical effects on the time-evolution of such properties. Short-chain waxes have a detrimental impact on the rutting resistance regardless of the blending protocol. On the contrary, long-chain waxes improve the overall behavior of the polyethylene-modified binders and, in particular, the resistance to permanent deformations.

Molecular separation of ions from aqueous solutions using modified nanocomposites

Herein, two novel porous polymer matrix nanocomposites were synthesized and used as adsorbents for heavy metal uptake. Methacrylate-modified large mesoporous silica FDU-12 was incorporated in poly(methyl methacrylate) matrix through an in-situ polymerization approach. For another, amine-modified FDU-12 was composited with Nylon 6,6 via a facile solution blending protocol. Various characterization techniques including small-angle X-ray scattering, FTIR spectroscopy, field emission-scanning electron microscopy, transmission electron microscopy, porosimetry, and thermogravimetric analysis have been applied to investigate the physical and chemical properties of the prepared materials. The adsorption of Pb(II) onto the synthesized nanocomposites was studied in a batch system. After study the effect of solution pH, adsorbent amount, contact time, and initial concentration of metal ion on the adsorption process, kinetic studies were also conducted. For both adsorbents, the Langmuir and pseudo-second-order models were found to be the best fit to predict isotherm and kinetics of adsorption. Based on the Langmuir model, maximum adsorption capacities of 105.3 and 109.9 mg g−1 were obtained for methacrylate-modified FDU-12/poly(methyl methacrylate) and amine-modified FDU-12/Nylon 6,6, respectively.

The Importance of Cooperativity in Polymer Blending: Toward Controlling the Thermoresponsive Behavior of Blended Block Copolymer Micelles.

Understanding, predicting, and controlling the self-assembly behavior of stimuli-responsive block copolymers remains a pertinent challenge. As such, the copolymer blending protocol provides an accessible methodology for obtaining a range of intermediate polymeric nanostructures simply by blending two or more block copolymers in the desired molar ratio to target specific stimuli-responsiveness. Herein, thermoresponsive diblock copolymers are blended in various combinations to investigate whether the resultant cloud point temperature can be modulated by simple manipulation of the molar ratio. Thermoresponsive amphiphilic diblock copolymers composed of statistical poly(n-butyl acrylate-co-N,N-dimethylacrylamide) core-forming blocks and four different thermoresponsive corona-forming blocks, namely poly(diethylene glycol monomethyl ether methacrylate) (p(DEGMA)), poly(N-isopropylacrylamide), poly(N,N-diethylacrylamide), and poly(oligo(ethylene glycol) monomethyl ether methacrylate) (p(OEGMA)) are selected for evaluation. Using variable temperature turbidimetry, the thermoresponsive behavior of blended diblock copolymer self-assemblies is assessed and compared to the thermoresponsive behavior of the constituent pure diblock copolymer micelles to determine whether comicellization is achieved and more significantly, whether the two blended corona-forming thermoresponsive blocks exhibit cooperative behavior. Interestingly, blended diblock copolymer micelles composed of p(DEGMA)/p(OEGMA) mixed coronae display cooperative behavior, highlighting the potential of copolymer blending for the preparation of stimuli-responsive nanomaterials in applications such as oil recovery, drug delivery, biosensing, and catalysis.

Effect of blending protocol on the performance of SBS/sulfur/soybean-derived additive composite modified hard asphalt

ABSTRACT This paper explores the feasibility of using SBS/sulfur/soybean-additive in combination in a hard asphalt binder to produce a composite modified asphalt binder. The modification effects of the additives and the influence of different blending protocols were comprehensively studied through laboratory investigations. The rheology of the asphalt binders was evaluated via viscosity, bitumen grading, master curve, Black diagram, isochronal plot, Han diagram, fatigue, creep stiffness and m-value using a bending beam rheometer (BBR), and Multiple Stress Recovery (MSCR) test using a Dynamic Shear Rheometer (DSR). The modified binder’s susceptibility to aging effects and thermal stability were also determined by calculation of the aging index (AI) and degree of separation. The results showed that the additives were able to enhance the overall performance of the hard neat Vacuum Tower Bottoms (VTBs) binder by increasing its resistance to rutting, fatigue cracking, and thermal cracking. It was also found that the additives reduced the aging susceptibility of the VTBs binder without any thermal stability or degradation issues after aging conditions. According to the overall performance of the modified binders, a blending protocol for producing a composite modified binder with optimal performance achieved through a well–developed cross-linked polymer elastic network was recommended.

Evaluation of Selected Performance Properties of Nanoclay-Modified Asphalt Binders

Asphalt binders are often modified with additives such as acid, polymer, or a combination of multiple additives to achieve improved performance to sustain heavy loads and adverse weather conditions. According to some previous researches, nanoclay can be a good alternative of currently practiced Styrene-Butadiene-Styrene (SBS) modification, and the former is expected to reduce the overall cost of the asphalt binder. Three types of nanoclay (Cloisite 10A, 11B, and 15A) were blended with asphalt binders prepared from two different sources (Arabian Crude and Canadian Crude). A blending protocol has been developed to blend nanoclay with the base binders. Mechanical properties including viscosity, rutting parameter have undergone significant changes after the nanoclay modification. It was also observed that nanoclay modified binders offer different moisture susceptibility while bonding with different aggregates; the nanoclay modified asphalt binder exhibits better bonding with gravel than sandstone. Mechanistic properties such as viscosity and rutting parameter are found to be highly correlated with the chemical compositions. Binders from the Canadian crude showed more colloidal stability than binders from the Arabian crude after nanoclay modification.

New insights on the compatibilization of PA6/ABS blends: A co-localized AFM-Raman study

Polyamides belong to the major class of engineering polymers with very attractive properties but fail in a brittle manner under stress concentrators. PA6/ABS blends are well-established commercial materials due to their stiffness/toughness balance even when stress concentrators are present. The pair PA6/ABS is immiscible and exhibits poor mechanical properties due to unfavorable interactions, thus, an efficient compatibilization is mandatory for practical applications. Deep understanding of the processing-structure-properties interplays requires multiple characterization techniques to provide insights on the impact of the processing/compatibilization on morphology and phases' distribution. In this work an advanced co-localized AFM-Raman strategy was used to study the compatibilization of PA6/ABS blends with SAN-g-Maleic Anhydride. AFM and TEM allowed nanomechanical analysis and characterization of the blends' morphologies. Co-localized AFM-Raman provided new fundamental insights on the compatibilizer's effect on the PA6's γ polymorphic crystallization. The amount and distribution of this γ phase were found to depend on the blending protocol.

Effect of organoclay incorporation and blending protocol on performance of PA6/ABS nanocomposites compatibilized with SANMA

The effect of organoclay incorporation and four different blending protocols on morphological, rheological, thermal, thermomechanical, and mechanical properties of PA6/ABS/SANMA/OMMT (55.0/35.0/5.0/5.0 wt%) nanocomposites was evaluated. As expected, even only with minor amounts of clay loading, significant reinforcement effect on mechanical and thermomechanical properties was achieved. Despite the morphological and structural similarities between studied compositions, it was found that mixing sequence might have great influence in mechanical properties, particularly in toughness. It is supposed that compatibilizing process though in situ reactions is much more efficient when PA6, ABS and SANMA are blended in the same extrusion step. Otherwise, when such condition is not satisfied, PA6/OMMT interactions seems to hamper the compatibilizing effect of SANMA, leading to inferior impact strength. POLYM. ENG. SCI., 57:1147–1154, 2017. © 2017 Society of Plastics Engineers

Influence of Blending Protocol on the Thermal and Mechanical Properties of HDPE/LLDPE Blend-Based Nanocomposites

AbstractNanocomposites based on high density polyethylene (HDPE)/linear low density polyethylene (LLDPE) blend were prepared by melt compounding in a twin-screw extruder using an organoclay (montmorillonite) as nano-filler and maleic anhydride-grafted linear low density polyethylene (LLDPE-g-MA) as compatibilizer. The effects of two blending protocols were also investigated. In the first blending protocol LLDPE and LLDPE-g-MA were first reinforced with organoclay and then this nanocomposite was later blended with HDPE, and the second blending protocol LLDPE-g-MA was mixed with organoclay first and then this masterbatch was diluted with HDPE and LLDPE. The preparation of the masterbatch resulted in the degradation of polyethylene, with crosslinking formation which increase the viscosity of the polymer and facilitated the dispersion of the organoclay in the polymeric matrix. WAXD and TEM were used to determine the effect of blending protocol and organoclay content on the intercalation and mechanical properties. The introduction of a maleated polyethylene was required to improve the organoclay dispersion in the nanocomposites. Thermal and mechanical properties of the nanocomposites were affected by blending protocols and the content of organoclay. The degree of crystallinity of the materials prepared using the first blending protocol decreased upon the intercalation of clay platelets whereas for the materials obtained using the second blending protocol the degree of crystallinity decreased due the crosslinking which further restricted mobility and diffusion of polymer chains. The nanocomposites show higher values of tensile modulus, flexural modulus and HDT compared to the blend without the addition of organoclay. The OMMT content added to the polymer blend results in significant and well correlated improvements in tensile and flexural moduli.

Studies on droplet size distributions during coalescence in immiscible polymer blends filled with silica nanoparticles

The effect of silica nanoparticles on the morphology of (10/90 wt%) PDMS/PBD blends during the shear induced coalescence of droplets of the minor phase at low shear rate was investigated systematically in situ by using an optical shear technique. Two blending procedures were used: silica nanoparticles were introduced to the blends by pre-blending silica particles first in PDMS dispersed phase (procedure 1) or in PBD matrix phase (procedure 2). Bimodal or unimodal droplet size distributions were observed for the filled blends during coalescence, which depend not so much on the surface characteristics of silica but mainly on blending procedure. For pure (10/90 wt%) PDMS/PBD blend, the droplet size distribution exhibits bimodality during the early coalescence. When silica nanoparticles (hydrophobic and hydrophilic) were added to the blends with procedure 1, bimodal droplet size distributions disappear and unimodal droplet size distributions can be maintained during coalescence; the shape of the different peaks is invariably Gaussian. Simultaneously, coalescence of the PDMS droplets was suppressed efficiently by the silica nanoparticles. It was proposed that with this blending procedure the nanoparticles should be mainly kinetically trapped at the interface or in the PDMS dispersed phase, which provides an efficient steric barrier against coalescence of the PDMS dispersed phase. However, bimodal droplet size distributions in the early stage of coalescence still occur when incorporating silica nanoparticles into the blends with procedure 2, and then coalescence of the PDMS droplets cannot be suppressed efficiently by the silica nanoparticles. It was proposed that with this blending protocol the nanoparticles should be mainly located in the PBD matrix phase, which leads to an inefficient steric barrier against coalescence of the PDMS dispersed phase; thus the morphology evolution in these filled blends is similar to that in pure blend and bimodal droplet size distributions can be observed during the early coalescence. These results imply that exploiting non-equilibrium processes by varying preparation protocol may provide an elegant route to regulate the temporal morphology of the filled blends during coalescence.

Effect of Blending Protocol on the Rheological Properties and Morphology of HDPE/LLDPE Blend-based Nanocomposites

Abstract Nanocomposites based on high density polyethylene (HDPE)/linear low density polyethylene (LLDPE) blend were prepared by melt compounding in a torque rheometer using an organoclay (montmorillonite) as nano-filler and maleic anhydride-grafted linear low density polyethylene (LLDPE-g-MA) as compatibilizer. The effects of five blending protocols on microstructure, crystallinity and rheological properties of the prepared samples were examined. The steady state rheological properties showed that the addition of nanoclay to the HDPE/LLDPE blend increased its shear viscosity at low shear rates changing the behavior of the HDPE/LLDPE matrix to a more pronounced shear thinning behavior. The blending sequence (LLDPE/LLDPE-g-MA/20A)/HDPE (where LLDPE and LLDPE-g-MA were first mixed with organoclay and then this system was later blended with HDPE) showed a lower slope of the log versus log curve and these results can be an indicative that the interactions between the matrix and the organoclay are stronger. The organoclay interlayer spacing and the crystallinity of the polymer domains were also influenced by the blending sequence. The crystallinity was calculated through the mathematical deconvolution of the peaks observed in the WAXD profiles. Overall, the crystallization of HDPE in the blends was hardly influenced by the presence of LLDPE. The blending sequence (LLDPE/LLDPE-g-MA/20A)/HDPE showed lower cristallinity when compared to others blending sequences. On the other hand, it was observed an increase in the organoclay interlayer spacing of this nanocomposite because the intercalation and/or exfoliation process occurs preferentially in the amorphous phase.

Size-controllable nanospheres prepared by blending a thermoset monomer in confined morphology with thermoplastic elastomer

Bisphenol-A based benzoxazine monomer (BZ) forms a polybenzoxazine (polyBZ) thermoset after thermal curing. However, when BZ is blended with polystyrene-block-poly(ethylene-co-1-butene)-block-polystyrene triblock copolymer (SEBS) matrices and is allowed to polymerize, phase separation at the nanometer level confines BZ in a way that can be controlled by the blending process, resulting in nanospherical polyBZ (polyBZ-NS) in the SEBS matrix. By simply changing the morphology of BZ and SEBS, through blending protocols ranging from sheet to electrospun micro-fibers and to electrospun core-sheath nanofibers, the sizes of polyBZ-NS so obtained vary from∼150–500 nm, to ∼80 nm, and to as low as ∼12 nm, respectively. This shows a new method to obtain well-defined mono-disperse nanospherical thermoset resins with a controllable size by controlling blend conditions.

Morphology and continuity development in highly reactive nanoscale polymer blends

This work examines the effect of the extent of reaction on morphology, continuity development and cocontinuity in highly reactive nanoscale blends of brominated poly(isobutylene-co-p-methylstyrene) (BIMSM) and polyamide (PA) containing different amounts of plasticizer. The reactive melt blending protocol used is shown to be very effective in generating fine droplets in the 50–80 nm range scale, as observed by atomic force microscopy, and producing high amounts (about 46%) of graft copolymer. The amount is even higher (about 57%) for plasticized blends. It can be seen that the reaction between the elastomer and PA shifts the percolation thresholds and overall continuity development in the system to higher concentrations, but no effect is observed on the concentration region of dual-phase continuity.When a plasticizer is added to the PA, and it is the matrix phase, elastomer continuity development and cocontinuity shifts to higher concentrations. This is a result of both the increased extent of reaction in the presence of a plasticizer and the lower viscosity of the PA phase. When plasticized PA is the dispersed phase, however, these two phenomena oppose each other. The increased extent of reaction shifts plasticized PA continuity development to even higher concentrations in the blend, but the lower viscosity of the plasticized PA phase shifts the continuity development to lower PA phase concentrations. The net effect is that no change is observed on PA phase continuity with addition of plasticizer in an elastomer matrix.It is found, overall, that the dominant factor in controlling the dispersion of higher concentrations of elastomer into the PA phase is the extent of reaction between BIMSM and polyamide.

Phase Behavior of Neat Triblock Copolymers and Copolymer/Homopolymer Blends Near Network Phase Windows

The phase behavior of poly(isoprene-b-styrene-b-methyl methacrylate) (ISM) copolymers near the styrene-rich network phase window was examined through the use of neat triblock copolymers and copolymer/homopolymer blends. Both end-block and middle-block blending protocols were employed using poly(isoprene) (PI), poly(methyl methacrylate) (PMMA), and poly(styrene) (PS) homopolymers. Blended specimens exhibited phase transformations to well-ordered nanostructures (at homopolymer loadings up to 26 vol % of the total blend volume). Morphological consistency between neat and blended specimens was established at various locations in the ISM phase space. Copolymer/homopolymer blending permitted the refinement of lamellar, hexagonally packed cylinder, and disordered melt phase boundaries as well as the identification of double gyroid (Q230), alternating gyroid (Q214), and orthorhombic (O70) network regimes. Additionally, the experimental phase diagram exhibited similar trends to those found in a theoretical ABC tri...

Effect of High Shear Blending Protocols and Blender Parameters on the Degree of API Agglomeration in Solid Formulations

This paper examines the effect of three protocols with several units and blender parameters on the mitigation of active pharmaceutical ingredient (API) agglomeration in solid formulations. The three protocols either preblend API with a portion of excipients in a high shear unit followed by dilution in a large blender or prepare the entire blend in a single blender followed by milling. In general, the three protocols yield blends with statistically similar API concentration variance and deagglomeration. The scale-up of the three protocols leads to more extensive API deagglomeration, which suggests that blender parameters still influence the degree of API deagglomeration, even when high shear units are present in the protocol. Lower blender fill levels and larger blenders lead to blends with fewer API agglomerates. Regarding the use of blender internals, results show that baffles have no substantial effect on API agglomeration. The inclusion of a moving internal (i.e., impeller) in a bin blender may not alw...

The Location and Extent of Exfoliation of Clay on the Fracture Mechanisms in Nylon 66-Based Ternary Nanocomposites

The primary focus of this work is to elucidate the location and extent of exfoliation of clay on fracture (under both static and dynamic loading conditions) of melt-compounded nylon 66/clay/SEBS-g-MA ternary nanocomposites fabricated by different blending sequences. Distinct microstructures are obtained depending on the blending protocol employed. The state of exfoliation and dispersion of clay in nylon 66 matrix and SEBS-g-MA phase are quantified and the presence of clay in rubber is shown to have a negative effect on the toughness of the nanocomposites. The level of toughness enhancement of ternary nanocomposites depends on the blending protocol and the capability of different fillers to activate the plastic deformation mechanisms in the matrix. These mechanisms include: cavitation of SEBS-g-MA phase, stretching of voided matrix material, interfacial debonding of SEBS-g-MA particles, debonding of intercalated clay embedded inside the SEBS-g-MA phase, and delamination of intercalated clay platelets. Based on these results, new insights and approaches for the processing of better toughened polymer ternary nanocomposites are discussed.

Biomolecule Assisted Hydrothermal Synthesis of Chainlike Network of Silver Sulfide Nanostructures

The primary focus of this work is to elucidate the location and extent of exfoliation of clay on fracture (under both static and dynamic loading conditions) of melt-compounded nylon 66/clay/SEBS-g-MA ternary nanocomposites fabricated by different blending sequences. Distinct microstructures are obtained depending on the blending protocol employed. The state of exfoliation and dispersion of clay in nylon 66 matrix and SEBS-g-MA phase are quantified and the presence of clay in rubber is shown to have a negative effect on the toughness of the nanocomposites. The level of toughness enhancement of ternary nanocomposites depends on the blending protocol and the capability of different fillers to activate the plastic deformation mechanisms in the matrix. These mechanisms include: cavitation of SEBS-g-MA phase, stretching of voided matrix material, interfacial debonding of SEBS-g-MA particles, debonding of intercalated clay embedded inside the SEBS-g-MA phase, and delamination of intercalated clay platelets. Based on these results, new insights and approaches for the processing of better toughened polymer ternary nanocomposites are discussed.