Effects of a hindered phenol compound on the dynamic mechanical properties of chlorinated polyethylene,acrylic rubber,and their blend

The dynamic mechanical properties of binary hybrids of chlorinated polyethylene (CPE) and acrylic rubber (ACM) with 3,9‐bis{1,1‐dimethyl‐2[β‐(3‐tert‐butyl‐4‐ hydroxy‐5‐methylphenyl)propionyloxy]ethyl}‐2,4,8,10‐tetraoxaspiro[5,5]‐undecane (AO‐80) and their ternary hybrids were investigated. The addition of AO‐80 was successful in tailoring the damping profile. The ACM/AO‐80 hybrids show only one relaxation, which is larger than that of pure ACM, whereas for the CPE/AO‐80 hybrids, one novel relaxation appears above the glass‐transition temperature of CPE. In the case of CPE/AO‐80/ACM, a supramolecular network was formed by a crosslink due to hydrogen bonding. The replacement of a part of CPE by ACM increased the value in the middle of two peaks. The AO‐80 molecule, which is a bifunctional hydrogen‐bonding acceptor, was found to act as a compatibilizer. In addition, in such ternary hybrids, the tan δ value in the middle of the two peaks was found to be proportional to the slope of the E′ curve at an identical temperature. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2468–2473, 2001     

Dynamic properties of an organic hybrid of chlorinated polyethylene and hindered phenol compound

The dynamic mechanical properties of hybrids of chlorinated polyethylene (CPE) and 3,9‐bis[1,1‐dimethyl‐2{β‐(3‐tert‐butyl‐4‐hydroxy‐5‐methylphenyl)propionyloxy}ethyl]‐2,4,8,10‐tetraoxaspiro[5,5]‐undecane (AO‐80) were investigated. The CPE/AO‐80 hybrids showed a novel relaxation in addition to the glass transition of CPE. The novel relaxation is attributed to the dissociation of intermolecular hydrogen bonds within the AO‐80–rich domain. The Payne effect, that is, the decrease of the storage modulus E′ with increasing strain amplitude and the appearance of a loss modulus E″ maximum at a strain of 0.6%, was observed for the CPE/AO‐80 hybrids. This result demonstrates that the AO‐80–rich domains within matrix polymer CPE form a network. The Payne effect is considered to be attributed to the mechanical disruption of segment–segment contacts at a sufficiently great strain. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1788–1793, 2001     

Preparation of high‐performance damping materials based on carboxylated nitrile rubber: Combination of organic hybridization and fiber reinforcement

The dynamic mechanical properties denoted by storage modulus (E′) and loss factor (tan δ) of binary and ternary systems consisting of carboxylated nitrile rubber (XNBR) filled with organic hindered phenol compound 2,2′‐methylenebis(6‐tert‐butyl‐4‐methylphenol) (AO‐2246) or/and short carbon fiber (SCF) were investigated. DMA results of binary XNBR/AO‐2246 system showed that by addition of AO‐2246, the tan δ peak maximum of XNBR was remarkably increased up to 3.5, and its peak position was also significantly shifted to room temperature, demonstrating that XNBR/AO‐2246 composite is a promising damping material. Nevertheless, application of such XNBR/AO‐2246 composite is limited due to its relatively low E′ value above glass transition temperature. Therefore, to develop a high‐performance damping material with high tan δ peak and high modulus as well as controllable tan δ peak position, the combination of organic hybridization and fiber reinforcement were adopted. DMA analysis of various ternary XNBR/AO‐2246/SCF systems revealed that by introduction of SCF, the E′ value of XNBR/AO‐2246 was increased remarkably while the tan δ peak maximum was still higher than 2.5. Thus, a new type of XNBR‐based high‐performance damping material was developed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Hydrogenated nitrile butadiene rubber and hindered phenol composite. I. Miscibility and dynamic mechanical property

In this study, miscibility and dynamic mechanical properties of hydrogenated nitrile butadiene rubber (HNBR) and 3,9‐bis{1,1‐dimethyl‐2‐[β‐(3‐tert‐butyl‐4‐hydroxy‐5‐methylphenyl) propionyloxy]ethyl}‐2,4,8,10‐tetraoxaspiro[5,5]‐undecane (AO‐80) composites were investigated. The composites with low‐AO‐80 content showed the incomplete miscibility, and a part of AO‐80 dissolved into HNBR, while the rest was dispersed into HNBR in the form of deep‐submicron‐sized microspheres based on the micromorphological and thermal analyses. However, with the increasing AO‐80 content, the system became completely miscible. When blending with AO‐80, the resulting composite exhibited the remarkably improved dynamic mechanical property. The loss tangent (tan δ) peak of the composites gradually shifted to room temperature with the increasing AO‐80 content. In this work, two classical equations (Gorden‐Taylor and Fox) were used to predict the glass transition temperature of the HNBR/AO‐80 composites. The calculated value based on Fox equation was more close to the experimental data. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers     

Effect of Hindered Phenol AO‐80 on the Damping Properties for Nitrile‐Butadiene Rubber/Phenolic Resin: Molecular Simulation and Experimental Study

A combined study of molecular dynamics (MD) simulation, experimental, and linear regression analysis method is presented for hindered phenol of 3,9‐bis[1,1‐dimethyl‐2‐{b‐(3‐tertbutyl‐4‐hydroxy‐5‐methylphenyl)propionyloxy}ethyl]‐2,4,8,10‐tetraoxaspiro‐[5,5]‐undecane (AO‐80)/nitrile‐butadiene rubber/linear phenolic resin (AO‐80/NBR/PR) composites with different AO‐80 contents to quantitatively establish the relations between microstructure and damping performance. The number of hydrogen bonds (N_HBs), the fractional free volume (FFV), and the binding energy (E_binding) of AO‐80/NBR/PR composites with different AO‐80 content are calculated by MD simulation from the microscopic scale. Damping parameters, including the loss factor peak (tan δ_max) and the loss peak area (TA) (tan δ > 0.3), are obtained by dynamic mechanical analysis from macroscopic scale. The quantitative relationships between microstructure parameters (N_HBs, E_binding, and FFV) and macroscopic damping properties (tan δ_max and TA) are obtained by linear regression analysis. This research is expected to provide a theoretical guidance for improving the damping performance of rubber‐based organic hybrid composites.     

Crystallization behaviour of hindered phenol on chlorinated polyethylene matrix

The crystallization behaviour of tetrakis[methylene‐3‐(3,5‐di‐tert‐butyl‐4‐hydroxyphenyl)propionyloxy]methane (AO‐60) molecules from several different states was investigated. It was found that, while pure AO‐60 is a crystalline substance, quenched and isothermally annealed AO‐60 is amorphous. In the case of a mixture of chlorinated polyethylene (CPE) and AO‐60, the crystallization of AO‐60 molecules is greatly affected by the initial dispersion state of the molecules. In addition, the mobility of AO‐60 molecules, which is governed by the annealing temperature and the distribution of the chain‐ends of CPE, also influences crystal growth. A CPE/AO‐60 hybrid annealed at a temperature near the melting point of AO‐60 exhibited several endothermal shoulders in addition to a sharper peak when characterized by differential scanning calorimetry. They were attributed to melting of the two kinds of crystal found either on the surface or inside the specimen. The former changes from polyhedron to platelet and then to needle shapes as the annealing temperature is reduced, whereas the latter exhibits some which are unprecedented such as deformed (warp, twist, turn and hollow) platelets. © 2001 Society of Chemical Industry     

Compatibilizers for recycling of the plastic mixture wastes. II. The effect of a compatibilizer for binary blends on the properties of ternary blends

In this article, we discuss the effect of a compatibilizer for binary blends on the properties of ternary blends composed of high‐density polyethylene (HDPE), polypropylene (PP), or polystyrene (PS) and poly(vinyl chloride) (PVC) virgin polymers with a simulated waste plastics fraction. Chlorinated polyethylene (CPE), ethylene–propylene rubber (EPR), and their 1/1 (w/w) mixture were tested as compatibilizers for the HDPE/PP/PVC ternary blend. CPE, styrene‐ethylene‐propylene block copolymer (SEP), or their 1/1 (w/w) mixture were tested as compatibilizers for the HDPE/PS/PVC ternary blend. The composition of the ternary blends were fixed at 8/1/1 by weight ratio. The amount of the compatibilizer was 3 phr. Rheological, mechanical, and thermal properties were measured. For the 8/1/1 HDPE/PP/PVC ternary blends, the tensile strength was slightly decreased, but the impact strength was significantly increased by adding EPR, CPE, or their mixture. EPR exhibited the most significant impact modification effect for the ternary blends. In a similar way, for 8/1/1 HDPE/PS/PVC ternary blends, on adding SEP, CPE, or their mixture, the tensile strength was slightly decreased, but the impact strength was noticeably increased. It was found that the SEP worked much better as an impact modifier for the ternary blends than CPE or the SEP/CPE mixture did. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1048–1053, 2000     

The effect of interface characteristics on the static and dynamic mechanical properties of three‐component polymer alloys

The effect of interfacial characteristics on the structure‐property relationships of ternary polymer alloys and blends comprising polypropylene (PP), ethylene‐vinyl alcohol copolymer (EVOH) and glass beads (GB) or fibers (GF) was investigated. The systems studied were based on a binary PP/EVOH immiscible blend, representing a blend of a semi‐crystalline apolar polymer with a semi‐crystalline highly polar copolymer. The ternary systems studied consisted of filler particles encapsulated by EVOH, with some of the minor EVOH component separately dispersed within the PP matrix. Modification of the interfacial properties was done using silane coupling agents for the EVOH/glass interface and compatibilization using a maleic anhydride grafted PP (MA‐g‐PP) for the PP/EVOH interface. Both glass fillers increased the dynamic modulus and decreased the damping of the neat polymers and of their binary blends, especially in the rubbery region. GF has a more profound effect on both the modulus and the damping. Glass surface treatments and compatibilization have only a marginal effect on the dynamic mechanical behavior of the ternary blends. Yet, compatibilization shifted the polymers' T_gS to higher temperatures. Both glass fillers increased the elastic modulus of the binary blends, where GF performed better than GB as a reinforcing agent. GF slightly increased the strength of the binary blends while, GB reduced it. Both fillers reduced the ductility of the binary blends. The blends' mechanical properties were related to the morphology and their components' crystallinity. The compatibilizer increases both stiffness and strength and reduces deformability.     

Dynamic supramolecular polymers built from cucurbit[n]urils and viologens

This review article focuses on supramolecular assemblies involving cucurbit[n]uril‐based containers and viologen guests as key building elements. Cucurbit[n]urils (CB[n], n = 5–8,10) are fascinating hosts forming a wide range of inclusion complexes (caviplexes) with 4,4′‐bipyridinium salts, known as viologens, either as discrete 1:1 inclusion compounds with CB[7] or as ternary inclusion compounds involving two hosts or two guests (2:1 with CB[7] and 1:2 or 1:1:1 with CB[8]). This property is currently being actively exploited to design and prepare self‐assembled dynamic stimuli‐responsive supramolecular polymers including gels, vesicles, films and organized arrays of polymeric microspheres or nanoparticles. This review highlights the main benefits of such polymers and gives an overview of the achievements and progress made in this field over the past decades. © 2018 Society of Chemical Industry     

Preparation and damping properties of (waste rubber powder)/hindered phenol composites

Waste rubber powder (WRP)/hindered phenol composites were successfully prepared by mixing tetrakis[methylene‐3‐(3‐5‐ditert‐butyl‐4‐hydroxy phenyl) propionyloxy] methane (AO‐60) into WRP for modification and recycling. The damping properties of the composites were systematically investigated through dynamic mechanical analysis. The experimental results indicate that the damping loss factor (tan δ) of WRP increases sharply from 0.366 to 0.734 via the modification process. With an increase in AO‐60, the tan δ value and the storage modulus in the glassy state gradually increase, and temperature dependence of loss peak gradually improves. The effects of the particle size of WRP, vulcanization temperature, vulcanization pressure, and vulcanization time on damping properties of the composite were investigated further. J. VINYL ADDIT. TECHNOL., 20:225–229, 2014. © 2014 Society of Plastics Engineers     

Structure and dynamic properties of nitrile‐butadiene rubber/hindered phenol composites

Crosslinked nitrile‐butadiene rubber (NBR)/hindered phenol composites were successfully prepared by mixing tetrakis [methylene‐3‐(3‐5‐ditert‐butyl‐4‐hydroxy phenyl) propionyloxy] methane (AO‐60) into NBR with 35% acrylonitrile mass fraction. The structural and mechanical properties of the NBR/AO‐60 composites were systematically investigated by using differential scanning calorimeter, XRD, Fourier transform infrared, scanning electronic microscope, dynamic mechanical analyzer, and tensile testing. The results indicated that the AO‐60 changed from crystalline form into amorphous form, and most of the AO‐60 molecules could be uniformly dispersed in the NBR matrix. The glass transition temperature (T_g) of NBR/AO‐60 composites increased gradually with increasing content of AO‐60. The increase in T_g could be attributed to the formation of a strong hydrogen bonding network between the AO‐60 molecules and the NBR matrix. Unlike the pure NBR, the NBR/AO‐60 rubber composites had only one transition with a high loss factor. With increasing content of AO‐60, the loss peak shifted to the high temperature region, the loss factor increased from 1.45 to 1.91, and the area under the tan δ versus temperature curve (TA) also showed a significant increase. All these results were ascribed to the good compatibility and strong intermolecular interactions between NBR and AO‐60. Furthermore, all NBR/AO‐60 composites exhibited higher glass transition temperatures and tensile strength than NBR, and they had other desirable mechanical properties. They have excellent prospects in damping material applications. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Hydrogenated nitrile butadiene rubber and hindered phenol composite. II. Characterization of hydrogen bonding

This article reports on the relationship between the variation of hydrogen bonding and macroscopic properties of composites composed of hydrogenated nitrile butadiene rubber (HNBR) and 3,9‐bis {1,1‐dimethyl‐2 [β‐(3‐tert‐butyl‐4‐hydroxy‐5‐methylphenyl) propionyloxy] ethyl}‐2,4,8,10‐tetraoxaspiro [5,5]‐undecane (AO‐80). Hydrogen bonding of the composites was studied by Fourier‐transform infrared (FT‐IR) and ultraviolet (UV) spectroscopies. FT‐IR spectra at room temperature revealed that the stretching vibration peak of O? H and C?O of AO‐80 red shifted with increasing AO‐80 content, whereas that of C≡N of HNBR blue shifted only when the AO‐80 content exceeded 10 parts per 100 resin (phr). At elevated temperatures, the shift was the opposite for C?O and C≡N bands resulting from hydrogen bonding dissociation. In the UV spectra, the E₂ band of benzene ring of AO‐80 exhibited two peaks differing in shape. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers     

Surface modification of MWCNT to improve the mechanical and thermal properties of natural rubber nanocomposites

In this study, we focused on the synergistic effect between carbon black (CB) and multiwall carbon nanotube (MWCNT) hybrid fillers. In particular, the surface modification of pristine MWCNT (P-MWCNT) via an acid (oxidation) treatment was used to improve their dispersion, as well as the mechanical and thermal properties of their corresponding natural rubber (NR)-based nanocomposites. Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) were carried out to determine the presence of functional groups on the oxidized MWCNT (O-MWCNT). After vulcanization, dynamic mechanical analysis (DMA), tensile properties, hardness, thermal conductivity, swelling behaviour in toluene and SEM characterizations were performed on both NR/CB/P-MWCNT- and NR/CB/O-MWCNT-based nanocomposites. The results showed the positive effect of MWCNT surface oxidation on the fillers' dispersion and nanocomposites' properties.     

Study on properties of natural rubber reinforced by poly(sodium‐4‐styrenesulfonate)‐decorated carbon black with a latex compounding technique

Natural rubber filled with poly(sodium‐4‐styrenesulfonate) (PSS)‐decorated carbon black (CB) by employing a latex compounding technique was prepared. The result of scanning electron microscope demonstrated that CB was uniformly dispersed in the matrix. Comparing to traditional dry compounding, an improvement in physical and mechanical properties was observed in the composites attributed to the homogeneous distribution of CB in matrix and an augment of bound rubber. Owing to the changes of the physical properties of CB surface, vulcanizate filled with oxidized CB via latex way exhibited higher mechanical properties. The resulting vulcanizates displayed a diminished interaction between fillers based on the consequence of strain dependence of storage modulus. Furthermore, a splendid wet‐skid resistance was obtained in vulcanizates fabricated by latex compounding technique in comparison with vulcanizates prepared by traditional dry compounding. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42346.     

Toughening effect of CPE on ASA/SAN binary blends at different temperatures

The effect of chlorinated polyethylene (CPE) on the impact toughness of acrylonitrile–styrene–acrylic (ASA) terpolymer/styrene–acrylonitrile copolymer (SAN) binary blends (25/75, w/w) was systematically investigated at three different temperatures (?30 °C, 0 °C, and 23 °C). With the addition of 60 phr CPE, the impact strength increased by 11 times at 23 °C and 10 times at 0 °C. However, the toughening effect was not obvious when the testing temperature was ?30 °C. Since the glass‐transition temperature (T_g) of CPE was about ?18.3 °C as measured with dynamic mechanical analysis tests, the polymeric chains of CPE have been “frozen out” at ?30 °C. As a result, CPE evidently cannot improve the toughness of the blend system. The morphology of impact‐fractured surfaces observed by scanning electron microscopy also confirmed the effect of CPE on the impact toughness of ASA/SAN binary blends. The heat distortion temperature remained almost unchanged, indicating that the improvement in toughness did not sacrifice heat resistance. Furthermore, other mechanical properties were evaluated, and the possible interactions among components of the blends were also analyzed by Fourier transform infrared spectra. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43353.     

Applications of Cucurbit[n]urils (n=7 or 8) in Pharmaceutical Sciences and Complexation of Biomolecules

Cucurbit[7]uril (CB[7]) and cucurbit[8]uril (CB[8]) are two key members of the cucurbit[n]uril (CB[n]) family of macrocycles. Because of the good water solubility of CB[7] and the unique ternary binding properties of CB[8], these two macrocycles have attracted increasing attentions in recent years. In particular, many promising reports of exciting applications regarding CB[7] and CB[8] have emerged in the pharmaceutical sciences and complexations of biomolecules, which has become one of the most important areas of potential applications of CB[n]s. This review summarizes the applications of macrocyclic CB[7], CB[8] and their derivatives as supramolecular platforms that have been developed in recent years within the field of pharmaceutical sciences and biomolecular sciences, and discusses the current challenges and future prospects of this area.     

Investigation on the morphological and mechanical properties of (polyamide 6)/(poly[styrene‐co‐acrylonitrile])/(poly[styrene‐b‐{ethylene‐co‐butylene}‐b‐styrene]) ternary blends

In this work, ternary polymer blends based on (polyamide 6)/(poly[styrene‐co‐acrylonitrile])/(poly[styrene‐b‐{ethylene‐co‐butylene}‐b‐styrene]) (SEBS) triblock copolymer and a varying concentration of the reactive (maleic anhydride)‐grafted SEBS were prepared by using a melt‐blending process. The effects of the material parameters (composition of ternary blends and SEBS/[{maleic anhydride}‐grafted SEBS] concentration ratio) and blending sequence on the morphological and mechanical properties of ternary blends were studied. Taguchi experimental design methodology was employed to design the experiments and select the material and processing parameters for the optimized mechanical properties. Tensile properties (Young's modulus and yield stress) and impact strength were considered as the response variables. It was demonstrated that there is a meaningful relationship between the composition of blends, processing parameters, observed phase structure, and obtained mechanical properties. The mechanical tests showed that the highest impact strength was achieved as the dispersion of the rubbery phase achieved an optimum size of about 1 μm. J. VINYL ADDIT. TECHNOL., 23:329–337, 2017. © 2015 Society of Plastics Engineers     

Characterization of cocoa butter substitutes,milk fat and cocoa butter mixtures

The melting properties and polymorphic behavior of binary and ternary blends of cocoa butter substitutes (CBS), cocoa butter (CB), and milk fat (MF) were studied by using pulsed nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), and X‐ray diffractometry (XRD). Hydrogenated palm kernel stearin (HPKS) and hydrogenated palm kernel olein (HPKO) were chosen as the two CBS feedstock fats. Both CBS/CB binary blends displayed significant eutectic behaviors. Multiple melting peaks and eutectic effects were observed at 30–50% addition levels of CB to HPKS. The range was broader in HPKO/CB blends. Dilution effect was observed in both CBS/MF blends while slight monotectic effect was also observed in HPKO/MF blends. Ternary phase diagrams and melting curves showed that eutectic effects existed in both ternary blends and the degree of interaction depended on the content of CB and MF. XRD results showed that when pure fat component in each blend exceeded 80%, its polymorphism dominated in the ternary blends. However, when CBS/CB or MF /CB were added at a comparative content (blends D and F), both β and β′ form existed. Practical applications: Phase properties of fat blends may have significant effects on the sensory characteristics and physical properties of the final products, such as hardness, brittleness, and the bloom formation. This study evaluates the melting properties and the polymorphic characteristics of fat blends of constituents with potential use in the manufacture of confectionery products. A comprehensive analysis of binary and ternary fat blends was conducted in order to provide a guide for compound chocolate production formulation.     

Dynamic mechanical properties and morphology of high‐density polyethylene/CaCO3 blends with and without an impact modifier

Dynamic mechanical analysis and differential scanning calorimetry were used to investigate the relaxations and crystallization of high‐density polyethylene (HDPE) reinforced with calcium carbonate (CaCO₃) particles and an elastomer. Five series of blends were designed and manufactured, including one series of binary blends composed of HDPE and amino acid treated CaCO₃ and four series of ternary blends composed of HDPE, treated or untreated CaCO₃, and a polyolefin elastomer [poly(ethylene‐co‐octene) (POE)] grafted with maleic anhydride. The analysis of the tan δ diagrams indicated that the ternary blends exhibited phase separation. The modulus increased significantly with the CaCO₃ content, and the glass‐transition temperature of POE was the leading parameter that controlled the mechanical properties of the ternary blends. The dynamic mechanical properties and crystallization of the blends were controlled by the synergistic effect of CaCO₃ and maleic anhydride grafted POE, which was favored by the core–shell structure of the inclusions. The treatment of the CaCO₃ filler had little influence on the mechanical properties and morphology. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3907–3914, 2007     

Relationship between morphology and mechanical properties of binary and compatibilized ternary blends of polypropylene and nylon 6

The effect of compatibilization on the morphology, mechanical properties, and dynamic mechanical properties of isotactic polypropylene (IPP)/nylon-6 (Ny-6) binary blends was investigated. Maleic anhydride (MAH) functionalized IPP was used as a compatibilizer in binary blends. The morphological, mechanical, and dynamic mechanical properties of binary and ternary blends were compared. The blends containing IPP-g-MAH showed more regular and finer dispersion of phases, different dynamic properties, and improved mechanical properties due to better adhesion between the two phases. The blends were also characterized for their flow properties and extent of water absorption. The melting peak temperature and percent crystallinity of IPP and Ny-6 phases were decreased in compatibilized blends. © 1996 John Wiley & Sons, Inc.