Addition Of SBS Research Articles

Toward the design of highly waterproof‐breathable electrospun nanofiber membrane based on π–π interactions

AbstractWaterproof and breathable nanofiber membranes are highly desirable for protective textiles; however, the practical application of nanofiber membranes is limited by fluorine‐containing material addition or complicated post‐treatment. Herein, we reported unique fluorine‐free polyurethane (PU)/poly(styrene‐b‐s‐b‐styrene) (SBS) nanofiber membranes by a facile direct electrospinning. Owing to the addition of SBS, the hydrophobicity, waterproofness, and mechanical properties of PU nanofiber membranes were dramatically enhanced. Furthermore, the highly interconnective channels were constructed after the introduction of SBS into the PU nanofiber membrane, which resulted in enhanced breathability. The enhancement in the comprehensive performance of the PU/SBS composite nanofiber membrane might be attributed to the π–π interactions between SBS and PU. By adjusting the concentration of the PU/SBS, fluorine‐free PU/SBS nanofiber membranes were optimized systematically, exhibiting satisfactory waterproofness (hydrostatic pressure, 47.4 kPa), acceptable breathability (water vapor transition rate, 5.6 kg m−2 d−1), and outstanding mechanical properties (breaking strength, 5.7 MPa; breaking elongation, 387.9%). The PU/SBS‐14 nanofiber membrane is ideal for wearable textiles, especially for outdoor protective clothing, wound dressings, and medical gowns.

Investigation of modification of petroleum bitumen with fine rubber crumb

Currently, in the world, due to the constant desire for recycling, many countries are considering the possibility of using rubber waste on roads. Bitumen modification for roads in Kazakhstan is considered one of the most suitable and popular approaches. This article presents the results of research on the modification of bitumen with rubber chips obtained from rubber waste. The document describes in detail the details of using rubber chips as bitumen modifiers, with particular emphasis on how they can potentially be used to improve bitumen performance and road durability. A wet process is used to produce rubber-bitumen binders. The wet process modifies the asphalt binder directly by pre-mixing with rubber crumbs at elevated temperatures, it leads to the fact that the material turns out to be the most stable, with increased elasticity and viscosity at high temperatures. The main physical and mechanical characteristics of the modified bitumen were determined after standard tests: penetration and plasticity, softening temperatures. The morphology of the modified bitumen was studied using scanning electron microscopy. The results confirm that bitumen modified with a rubber crumb with the addition of SBS meets the requirements for a polymer-bitumen binder of Kazakhstani standards and, according to its physico-chemical characteristics, is suitable for the production of modified bitumen.

Viscoelasticity, Tensile properties, and Microstructure of Cyclic Olefin Copolymer/SBS/SEBS Elastomer Blends

AbstractCyclic olefin copolymer (COC) polymers with rigid ring structures like NB in the polymer chain enhance the toughness greatly, but also cause high brittleness of the material, which limits its application. Modification of COC for toughness by the addition of styrene‐butadiene‐styrene block copolymer (SBS) and polystyrene‐block‐poly(ethene‐co‐butyl‐1‐ene)‐block‐polystyrene (SEBS) elastomers of styrene content in SEBS is done. Field emission scanning electron microscope shows that tougheners are uniformly dispersed in the COC matrix without a visible interface between the two phases, which is also supported by the Cole‐Cole and Han curves. Rheological behavior indicates that the addition of SBS and SEBS makes the COC/SBS/SEBS composites to have higher elastic modulus, loss modulus, and composite viscosity than that of pure COC. Furthermore, the tensile strength of the composite presents 3.6 times higher than pure COC, while the elongation at break is 6.3 times higher than pure COC. The dynamic mechanical analysis reveals that the COC and tougheners are well blended, and the SBS and SEBS toughen the COC in agreement with the results of morphological and rheological behaviors.

Features of dimentional design system for asphalt concrete mix on superpave technology and bituminous binder of pg grade determination

Introduction. This article discusses the technology of designing asphalt concrete pavements, using the Superpave method. The Superpave (SUperior PERforming Asphalt PAVEments) system was developed by the Strategic Highway Research Program (SHRP) in the USA. The aim of the program was to find new ways of designing asphalt concrete pavements that will work better at extreme temperatures and heavy traffic loads.Currently, the system of volumetric design of asphalt concrete mixtures is being actively implemented in Russian road construction industry. This is an adaptation of the American Superpave method and is being implemented in our country in the form of a series of new standards. The Superpave volumetric and functional design system in particular addresses several pavement-related problems: permanent deformation, which results from poor asphalt mix shear strength at high temperatures, and low temperature damage, which occurs when the asphalt pavement is subjected to stress exceeding the compressive and tensile strength. The elimination of the above problems is carried out due to the most reasonable selection of the components of the asphalt concrete mixture.Materials and methods. Studies of bitumen binders were carried out according to the methods laid down in the technical requirements: GOST R 58400.1-2019 Public roads. Materials binding petroleum bitumen. Technical requirements taking into account the temperature ranges of operation.The selection of the PG brand of bitumen binder using Superpave technology was carried out using the example of a polymer-bitumen binder that meets the requirements of GOST 52056-2003 PBB 90 (sample 4) and a bitumen binder obtained from tar with the addition of thermoplastic elastomer (hereinafter referred to as TEP) of the SBS type that meets the requirements of GOST 52056-2003 PBB 90 (sample 3).Results. The article provides a review of technical documentation in order to familiarize with the methodology for selecting the brand of bituminous binder for asphalt mix. In the course of the research, the technological features of the system of volumetric functional design of the asphalt concrete mixture according to the Superpave method, as well as the determination of the brand of bituminous binder, were considered. The introduction of foreign experience in road construction can contribute to the improvement and improvement of the quality of Russian roads.Discussion and conclusions. Based on the experimental data carried out in the work, it can be concluded that the goal has been achieved, namely, the brands of bitumen binder have been selected using Superpave technology that meet the requirements of GOST R 58400.1–2019 and GOST R 58400.2-2019, namely for polymer-bitumen binder (PBB 90 according to GOST 52056-2003) – PG 58-28, and on the basis of tar with the addition of SBS – PG 64-28 grade TEP, respectively.Having studied the physical and chemical characteristics of the initial reagents, as well as the results of numerous chemical experiments, brands of PG bitumen binders were selected using Superpave technology and depending on climatic conditions and transport loads GOST R 58400.1-2019 Public roads. Materials binding petroleum bitumen. Technical requirements taking into account the temperature ranges of operation and GOST R 58400.22019 Public roads. Materials binding petroleum bitumen. Technical requirements taking into account the levels of operational transport loads.

Study on rheological and micro-structural properties of different modified asphalt by using organic and inorganic modifier

In order to evaluate the high and low temperature rheological properties of different modified asphalt, this paper prepared different types of modifiers and short-term aging modified asphalt (RTFOT), using dynamic shear rheometer (DSR) and bending beam rheological test (BBR) to compare and analyze the deformation resistance and stress sensitivity of different types (organic and inorganic) modified asphalt, determine its PG classification, and evaluate its fitting parameters with the help of Burgers model. The low-temperature mechanical properties of the fitting parameters were evaluated by the Burgers model; the chemical composition of different modified asphalts was analyzed by Fourier transform infrared spectroscopy (FTIR), and the microscopic state of the modified asphalts was observed by fluorescence microscopy. The results show that: with the increase of temperature, the high temperature deformation resistance of organic modified asphalt is better than that of inorganic modified asphalt, and PE modified asphalt is the best, and the low temperature performance of inorganic modified asphalt is poor, and the addition of SBS It will improve the low temperature crack resistance of asphalt. The road performance of different modified asphalts from strong to weak are PE modified asphalt, SBS modified asphalt, diatomite modified asphalt, montmorillonite modified asphalt. The research results have certain reference value for further research on different types (organic and inorganic) of modified asphalt.

Effect of Styrene Butadiene Styrene on Properties of Open-Graded Asphalt Concrete Mixtures

Open graded asphalt mixture is becoming more widespread where it is applied for various purposes, e.g. drainage of rainwater effectivity, traffic safety (high skid resistance), and controlling pollution noise. However, it has many other disadvantages, of which low stability, high stripping, and moisture sensitivity. The research aims to study the effect of styrene butadiene styrene SBS addition on the volumetric and mechanical properties of open graded mixture. In this research one type of aggregate with gradation (12.5 mm NMAS), asphalt of penetration grade (40/50), and cement as filler were used. Optimum asphalt content was selected based on the criteria of air voids content, asphalt drain down, permeability, and abrasion resistance (for aged and un-aged) samples. Other properties of open-graded mixtures, such as indirect tensile strength (ITS), moisture susceptibility, Marshall stability and flow were evaluated. The results show that addition of polymer (SBS) leads to an enhancement in the properties of the modified mixtures. There is an improvement in Marshall parameters. Also, a slight decreasing is noticed for permeability and air voids. For Cantabro abrasion loss (aging and un-aging condition), the abrasion resistance is increased, the drain down of asphalt is decreased from original mixture by addition of SBS. Finally, the moisture sensitivity is improved indicating that modified mixes becomes more resistant to water damage.

Properties of SBS/MCF-Modified Asphalts Mixtures Used for Ultra-Thin Overlays

In order to produce high-viscosity and high-toughness asphalt for ultra-thin overlays, the conventional asphalt cement was modified with high-content SBS and micro carbon fiber (MCF). The performances of the modified asphalt were studied by tests of penetration, softening point, ductility, kinematic viscosity, multiple stress creep recovery (MSCR), and by dynamic shear rheometer (DSR) and bending beam rheometer (BBR). Mixture properties were studied by tests of rutting, low-temperature bending, freeze–thaw splitting, four-point bending fatigue and dynamic modulus. The results reflect that the addition of MCF could enormously improve the high- and low-temperature properties, increase the viscosity of asphalt, and improve the toughness of asphalt. When SBS content was 6%, with the increase of MCF content, G*/sin δ and R values first increased and then decreased, and the Jnr value first decreased and then increased. When MCF content was 0.8%, the overall performance was best. Adding MCF into an asphalt mixture or increasing the content of SBS improved the rutting resistance, low-temperature crack resistance, water stability, and fatigue performance of the asphalt mixture. At the same temperature and frequency, there was little difference in phase angle between the 6%SBS + 0.8%MCF and 5%SBS + 0.0%MCF modified asphalt mixtures, and the dynamic modulus was slightly higher over the whole range. It can be concluded that the addition of SBS and MCF can enormously enhance the viscosity and toughness of asphalt. The viscosity of the 6%SBS + 0.8%MCF modified asphalt met the performance requirements of high-viscosity asphalt. When used for ultra-thin overlays, it had great road service performance and met the application requirements.

PROSPECTS FOR THE USE OF SECONDARY MILK RAW MATERIALS IN RESTAURANT TECHNOLOGY TECHNOLOGIES

The most important indicator of the food products is the biological value, which characterizes the quantity and the power factor of the quality of the protein, which is associated with over-fertilization and the degree of balance for the amino acid composition. The problem of savory value of yeast dough, bakery sprouts and their assimilation of doses is relevant. Apparently, part of the amino acids is consumed during the process of preparing bread, during the cooking time as a result of the reaction of melanoid-forming (proteins pass from the undigested form to lysin, histidine, grutamine, tryptophan). Oxidation of the critical amino acids of cystine and cysteine is carried out until the conversion of the unconquered form of cysteic acid. In the final result, the biological value of bakery products is reduced even more and without that. In this way, the low biological value of whites of wheat boroshna is necessary to introduce additives into the recipe of bakery additives in order to increase the amount of whites and make a larger warehouse, lower whites of wheat boroshna. The paper proves the prospects of using dry protein-carbohydrate semi-finished product (SBVN) to increase the biological value of bakery products. The chemical and amino acid composition of SBVN was studied. The high biological value of the semi-finished product is proved. It is established that the use of SBVN in the technological process of yeast dough production provides an opportunity not only to increase the biological value, but also to purposefully influence the technological properties of the dough and the intensity of fermentation. The effect of the additive on the gas-forming ability of the dough has been studied. It is established that the addition of SBS in the amount of 15% by weight of flour helps to improve the technological properties of yeast dough.

Study of the Properties of Open Graded Asphalt Mixtures With the addition of SBS

Porous asphalt (PA) is widely used in a growing number of countries where porous asphalt is applied for a variety of purposes, e.g. for the effective drainage of rainwater, traffic safety (high slip resistance), the control of noise pollution and lower temperatures surrounding the city. However, it has many other disadvantages, such as poor resistance to rutting, poor resistance to fatigue, and PA is susceptible to raveling (wastage of aggregates from the pavement surface), due to effects of climatic and traffic loading. In general, this type of mixtures is not as good as traditional mixtures. This research aims to study and improve the properties of porous mixtures using SBS. In this paper, laboratory tests were carried out to the materials involved in the composition of this mixture: binder, aggregate, and additive. SBS is used in the proportion of (2.0, 3.0, and 4.0) % of the weight of the binder. It was found that this additive leads to reduce the permeability and air void, but not as large as that without polymer modifier by (1.7 %, 3%, and 3.5%), while in the case of abrasion loss (aged and unaged) decrease by (4.1, 6.67 and 10.92) (4.7, 6.3and 2.6)% respectively. The drain down value is decreased by (16.5%, 38.25%, and 43.51%) respectively, from original asphalt cement.

Polymer Additive SBS: More Sensitive to Fluorinated Asymmetric‐Indenothiophene‐Based Polymer Solar Cells

AbstractPolymer solar cells (PSCs) typically suffer from a negative effect of the residual solvent on the performance due to the use of the solvent processing additive. One solution to solve this problem is to use a solid polymer additive that can promote the phase separation of the blend film of the active layers. In this work, two new D−A type photovoltaic polymers, namely PIT‐DTBT and PIT‐DTffBT, based on asymmetric indenothiophene (IT) donor unit and nonfluorinated or difluorinated benzothiadiazole acceptor unit were designed and synthesized, respectively. Then a triblock copolymer, poly(styrene‐block‐butadiene‐block‐styrene) (SBS), was employed as a polymer additive into the active layers of PIT‐DTBT/PC71BM and PIT‐DTffBT/PC71BM based devices, and the SBS effect on the morphology of the blend films of the active layers, and then the performance of the two kinds of devices was investigated. The results demonstrated that the addition of SBS improved the molecule packing and induced the crystallization of PIT‐DTffBT, making the device have higher charge mobilities, more efficient charge dissociation and collection, and less charge recombination. Thus, power conversion efficiency (PCE) was increased from 4.61 % to 6.57 % for PIT‐DTffBT based device. Although almost no improvement in molecule packing and crystallization was observed for SBS‐treated nonfluorinated PIT‐DTBT, the fact of PCE of the PIT‐DTBT based device increased from 2.94 % to 3.13 % can also be attributed to the improved phase separation of the blend film by SBS. These findings indicate that SBS is more sensitive to fluorinated polymers than nonfluorinated polymers in improving molecule packing and inducing crystallization.

Laboratory investigation on the microstructure and performance of SBS modified epoxy asphalt binder

Both styrene–butadiene-styrene copolymer (SBS) and epoxy resin have been widely applied in the asphalt modification. The influence of SBS concentration on the morphology, viscosity, thermal stability, glass transition temperature (Tg), damping performance and mechanical behaviors of the neat EA binder was studied. Double phase separation occurred in the epoxy SBS modified asphalt (ESBA): main phase separation between epoxy and the SBS modified asphalt (SBA) and secondary phase separation between asphalt and SBS. The occurrence of phase separation in the ESBA disrupted the original dispersion of SBS particles in SBA and resulted in the redistribution of SBS in the form of smaller spherical particles. The inclusion of SBS increased the viscosity of the neat EA. Furthermore, the viscosity of ESBAs increased with the SBS content. ESBAs had as long as 150-min construction time for the mixture pavement. The presence of SBS improved the thermostability of the neat EA. In terms of ESBAs, the thermostability increased with the SBS content. The addition of SBS lowered the Tg of the neat EA when the SBS content was lower than 4 wt%. The Tg of ESBAs increased with the SBS content. The incorporation of SBS significantly enhanced the damping behaviors of the neat EA. The tensile strength of the neat EA was improved with the addition of 2 wt% SBS. The inclusion of SBS improved the elongation at break and the toughness of the neat EA when the SBS loading was greater than 1 wt%.

Comparative evaluation of moisture susceptibility of modified/foamed asphalt binders combined with different types of aggregates using surface free energy approach

Moisture damage in asphalt pavement is a major concern for the state and federal highway agencies for many years. The surface free energy (SFE) is demonstrated to be a reliable mechanistic approach for evaluating the moisture-induced damage potential of asphalt mixes. The objective of this study was to use SFE approach to evaluate the effects of foamed/modified asphalt binders and aggregate type on the moisture susceptibility of asphalt mixes. The SFE components (polar and dispersion) of PG 64-22 asphalt binders, modified with 2–4% SBS, 2–4% nanoclay, 2–4% fly ash, 3.5% devulcanized rubber (DVR), or foamed by injecting water, were estimated from contact angle measurement. Also, the SFE components of five types of aggregates, namely limestone, gravel, basalt, granite, and sandstone were obtained from the literature. The energy ratio parameters calculated from the work of cohesion and adhesion were used to estimate the moisture-induced damage potential of various asphalt mixtures. The results showed that the total SFE and work of cohesion of PG 64-22 increased with the addition of SBS, nanoclay, and fly ash while decreased with the use of DVR and foaming process in asphalt binder. Based on the energy ratio parameters, the combination of asphalt binder with different types of aggregates has been recommended with the resistance to moisture-induced damage potential. The results presented herein are expected to assist in selecting appropriate asphalt binder and aggregates with desirable moisture resistance.

Positive effects of side-chain fluorination and polymer additive SBS on the enhanced performance of asymmetric-indenothiophene-based polymer solar cells

Two new D-A type photovoltaic polymers, namely PITPh-DfQx and PITPhf-DfQx, based on asymmetric indenothiophene (IT) donor units with alkoxyphenyl or fluoroalkoxyphenyl substitutes were designed and synthesized. Effects of the fluorine substitution in the asymmetric IT donor units on the electronic structure, ordering structure, photovoltaic properties, and charge generation and recombination dynamics were investigated. It is found that side-chain fluorination in the asymmetric donor units of the D-A polymers endowed the relative polymers with a deeper HOMO level, higher and more balanced charge mobilites, increased charge dissociation efficiency and reduced bimolecular recombination. As a result, the bulk heterojunction solar cell based on the blend film of PITPhf-DfQx and PC71BM demonstrated an efficiency of 6.10%, whereas the cell efficiency based on PITPh-DfQx was only 3.00%. In addition, a triblock copolymer, poly(styrene-block-butadiene-block-styrene) (SBS), was employed for the first time as a polymer additive into the active layers based on PITPh-DfQx/PC71BM and PITPhf-DfQx/PC71BM devices to promote donor crystallization and tune the extent of phase separation between the donor and acceptor. The presence of SBS obviously improved the molecule packing and induced the crystallization of the two polymers, giving rise to a better phase separation due to enhanced aggregation effect of photovoltaic polymers. Therefore, with a small addition of SBS, the optimal PCE was further increased from 6.10% to 6.60% for PITPhf-DfQx based device and from 3.00% to 5.50% for PITPh-DfQx based device. The positive effects of SBS additive on the performance of photovoltaic polymer/fullerene BHJ solar cells provide a new strategy for developing high performance polymer solar cells.

Mechanical Analysis of Asphalt Pavements with Alternative Materials in Manaus - Amazonas

Pathologies in urban roads are common and recurring problems in the municipality of Manaus - AM, where defects have appeared early and successfully, especially the climatic condition of the differentiated region and the non-participation of the coarse aggregate in the asphaltic coating and sublayers. predominantly made of clay. Nevertheless, the Government often performs simple "hole-covering" operations to recover and restore such a structure, corroborating all the problems that trigger poor paving in the State Capital of Amazonas. Another challenge of the municipal administration is the disposal of construction waste, making it necessary to recycle it, highlighting the serious environmental problem caused by the extraction of the pebble. Aiming to contribute with alternatives the scarcity of stone material and the natural aggregate (pebble), substitute of gravel in the regional civil construction, it is proposed the use of construction and demolition waste (RCD). Asphalt concrete (AS) mixtures were made with recycled material, residual sand, portland cement, petroleum asphalt cement (CAP 50/70) and this binder modified with the addition of SBS (styrene and butadiene copolymer). Characterization tests were performed with aggregates, filler and petroleum asphalt cement (original and polymer), dosed by the Marshall method, and the asphalt mixtures were subjected to the Beam Fatigue Test at three different stress levels. The studies indicated satisfactory results of asphalt mixtures with the participation of RCD and SBS binder, compared to regional composites.

The Performance of SBS Modified asphalt binder base on the MSCR Test

SBS modified asphalt has been generally used to improve the high temperature performance of asphalt pavement in past decades. This research work evaluated the effect of SBS on high temperature performance of asphalt binder in ways of Multiple Stress Creep Recovery (MSCR). The penetration, softening point and MSCR test were conducted in order to come to conclusions regarding high temperature rutting performance of SBS modified asphalt binders. The amount of SBS was varied as 3%, 4% and 5% by the weight of the base binder. Based on Jnr and R%, addition of SBS to the base asphalt binder help in significantly improving the rutting resistivity potential.

Microstructures, thermal and mechanical properties of epoxy asphalt binder modified by SBS containing various styrene-butadiene structures

As the most important thermoplastic and thermosetting modifiers, styrene–butadiene–styrene triblock copolymer (SBS) and epoxy resin have been widely applied in asphalt modifications. In this paper, epoxy SBS-modified asphalts (ESBAs) were prepared with epoxy monomer, curing agent and SBS-modified asphalts (SBAs) with various styrene–butadiene structures, which in turn were subjected to laser scanning confocal microscopy (LSCM), viscous measurements, thermal analysis and tensile tests. The LSCM results revealed that both polymer-rich phase and fluorescent particle-rich phase were observed in the asphalt matrix. Moreover, the number of SBS particles in SBAs increased with the increase of styrene contents. The presence of SBS decreased the size of dispersed domains in the continuous epoxy phase of the neat epoxy asphalt binder (EAB). For ESBAs, a double phase separation occurred between SBA and epoxy in the continuous epoxy phase and between asphalt and SBS in the dispersed SBA phase. Both number and size of SBS domains in the dispersed SBA phase of ESBAs increased with the increase of styrene contents. The inclusion of styrenic polymers increased the viscosity of the neat EAB. The viscosity of ESBAs increased with the increase of average molecular weights of the styrenic polymers. The addition of styrenic polymers increased the glass transition temperature (Tg) and storage modulus (E′) of the neat EAB. Meanwhile, the inclusion of styrenic polymers weakened the damping properties of the neat EAB. The styrene-butadiene structures had little effect on the Tg and damping properties of ESBAs. The E′ of ESBAs decreased with the increase of styrene contents. The presence of SBS enhanced the thermal stability of the neat EAB. Tensile results showed that the addition of SBS increased the tensile strength of the neat EAB.

Effects of nanoclay and nanocomposites on bitumen rheological properties

Nanoclays have been successfully introduced into the asphalt, either separated or in the form of polymer/bitumen blends, improving mechanical and rheological properties. In this paper, the organoclay montmorillonite (OMMT) was prepared to be used as an additive for bitumen and for a polymer modified bitumen. A nanoclay Cloisite® 20Å (CLO), was also investigated for comparison purposes. A bitumen was modified with 4% nanoclays (OMMT and CLO), with 4% SBS, and with 4% SBS/nanoclay. All modified bitumens (MB) exhibited higher G∗ and lower δ, indicating an improvement in the stiffness and in the elasticity. SBS/Nanoclay MB presented similar rheological behavior compared to SBS MB which may result in cost savings. The addition of SBS and SBS/OMMT resulted in increase in PG grade and decrease in non-recoverable creep compliance (Jnr) indicating a better rut resistant compared to pure bitumen.

Study on Performance of SBS Modified Asphalt

SBS is a styrene - butadiene - styrene block copolymer, the addition of SBS of high and low temperature performance and road can be very good to improve the performance of asphalt. This paper studied the performance of the modified asphalt on the content of modifier.

Structure, thermal properties and mechanical properties of sPS-based nanocomposites with and without styrenic elastomer inclusions

Syndiotactic polystyrene (sPS)-based nanocomposites with and without toughener inclusions were successfully prepared. One organo-montmorillonite (20A) and two styrenic elastomers (SBS and SEBS) served as the reinforcing filler and as tougheners, respectively. XRD and TEM results confirmed the achievement of intercalated and partially exfoliated sPS/20A nanocomposites. The presence of SBS or SEBS slightly depressed the dispersibility of 20A. DSC results indicated that 20A inhibited the crystallization of sPS. The presence of SBS or SEBS further retarded the crystallization of sPS; this effect was more apparent with SEBS. The presences of 20A and SBS/SEBS facilitated the formation of α-form sPS crystals. The thermal stability enhancement of sPS/20A nanocomposites was confirmed, and was further improved with the inclusion of SBS or SEBS. The stiffness of sPS increased with the sole addition of 20A. The addition of SBS or SEBS greatly increased the impact strength of the composites, especially with the addition of SEBS. The achievement of toughened sPS-based nanocomposites was confirmed.

Thermal stability of polyoxymethylene and its blends with poly(ethylene-methylacrylate) or poly(styrene-butadiene-styrene)

Polyoxymethylene (POM) copolymer and its blends with poly(ethylene-methylacrylate) (EMA) or poly(styrene-butadiene-styrene) (SBS) up to 5 wt % were conducted to thermooxidative ageing in oven at 140°C for 111 days. POM showed continued degradation as seen from the gradual decrease in the crystallization temperature from differential scanning calorimetry (DSC) study, while no change in Fourier transform infrared spectra (FTIR) and low weight loss were observed (2.5% after 111 days' ageing). The POM degradation was characterized by the initial increase of crystallinity due to crystal perfection, which then kept nearly unchanged until 35 days' ageing, and lastly increased again to result in embrittlement and decrease in tensile strength. Increase in the tensile stress and strain was observed up to 35 days' ageing. POM blends with SBS or EMA had similar degradation behavior as POM, but addition of SBS accelerated the POM degradation significantly, while POM blend with 1 or 3% EMA just showed slightly lower thermal stability than POM. Degradation in POM and SBS/POM occurred in amorphous phase while EMA/POM degraded in both amorphous and crystal phase. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011