Swelling Agents Research Articles

Investigation of swelling degree of polypropylene beads with monomers and blowing agents

AbstractThe swelling step of polymer particles or beads with blowing agents and monomers is one of the factors that directly affect the performance properties of expandable core–shell particles, including morphology, composition, and expansion degree. In this regard, the present work investigated the effect of swelling agents on polypropylene (PP) beads. Swelling agents were used to perform swelling tests in both bulk and suspension media at different temperatures and stirring rates. Additionally, a mass transfer model was implemented to predict the swelling degree at the analyzed experimental conditions. The obtained results indicated the important effect of temperature on swelling in both bulk and suspension tests. Among the investigated swelling agents, higher rates of PP beads swelling were observed when styrene was employed (~80 wt%), when compared to methyl methacrylate (~20 wt%), vinyl acetate (~9 wt%), and acrylonitrile (~6 wt%). Moreover, it seems that the stirring rate does not exert a considerable influence on the swelling rates, indicating that swelling is controlled by thermodynamic constraints and particle properties. Finally, experimental results showed that the final saturation concentration of the swelling agent can be reached before 1 hour of swelling, indicating that the swelling kinetics can be much faster than the polymerization kinetics.Highlights The effects of non‐conventional swelling agents on PP were investigated. The swelling presented a fast dynamic behavior. The swelling dynamics was controlled by the solubility of the swelling agent. The highest swelling degree was obtained with styrene.

Low-Temperature Mechano-Chemical Rubber Reclamation Using Terpinene as a Swelling Agent to Enhance Bond-Breaking Selectivity.

Common swelling agents used in the mechano-chemical rubber devulcanization process usually require high temperatures to achieve satisfactory swelling effects, which results in severe production of pollutants and reduces the selectivity of bond scissions. This work presents an environmentally friendly swelling agent, terpinene, which can swell the rubber crosslink structures at low temperatures. Both a rubber swelling experiment and a rubber reclaiming experiment with a mechano-chemical devulcanization method are conducted to explore the swelling effects of terpinene. After soaking in terpinene at 60 °C for 90 min, the length elongation of the rubber sample reaches 1.55, which is much higher than that in naphthenic oil and is comparable to that in toluene. When adding 3 phr of terpinene for every 100 phr of waste rubber during the reclaiming process, the bond scissions exhibit high selectivity. After revulcanization, the reclaimed rubbers have a tensile strength of 17 MPa and a breaking elongation of 400%. Consequently, the application of terpinene as the swelling agent in the LTMD method can greatly improve the properties of reclaimed rubbers, thereby enhancing the dual value for the economy and environment.

Collapsed and re-swollen archaeological wood: efficiency and effects on the chemical and viscoelastic characteristics of wood

• Swelling agents evaluated for the shape recovery of collapsed archaeological wood • Effects of treatments on viscoelastic characteristics assessed by dynamical mechanical analysis (DMA) • Strongly alkaline systems reached full recover of the original shape • Treatments induced crystallinity depletion in cellulose and partial removal of the already decayed lignin • Stiffness reduced and dissipative behaviour increased after treatments in alkaline conditions The efficiency of different swelling agents in recovering the shape of collapsed archaeological wood (where the original object figure is lost) was evaluated. Furthermore, the effect of these treatments on the chemical and viscoelastic characteristics of wood was assessed by dynamical mechanical analysis (DMA). In preliminary trials, carried out on both alder ( Alnus spp) and a highly decayed ash wood ( Fraxinus excelsior L.), the efficiency of various organic solvents (dimethylsulfoxide, ethylene diamine, ethylene glycol, ethylene glycol mono butyl ether, N,N-dimethylacetamide) and active alkali urea (an experimental treatment previously proposed for collapsed wood) was considered in relation to three working temperatures. Following, medium decayed Scots pine ( Pinus sylvestris L.), highly decayed maritime pine ( Pinus pinaster Aiton), and two differently decayed oak woods ( Quercus spp) were used to investigate the effects of the three best agents on the viscoelastic properties of wood and, again, their efficiency. Tests demonstrated that in most decayed samples, although high swelling was obtained, lignin was lost and a substantial weight decrease was observed. However, in least decayed samples a loss of cellulose crystallinity was detected. These occurrences reflected on both samples stiffness (that strongly reduced after treatments) and dissipative behaviour (an increase of damping factors could be observed after treatments in alkaline conditions). Thus, swelling agents, although satisfactory in the shape recovery of collapsed wood, should be used only in cases of real injury imputable to collapse (a specific consolidation treatment should be considered in addition).

Solvent Assisted Dyeing of Silk Fabric Using Deep Eutectic Solvent as a Swelling Agent

Solvent assisted dyeing of silk fabric was studied with the aim to increase color strength of silk fabric with the help of green, eco-friendly deep eutectic solvent (DES), which act as a swelling agent. The use of a DES in solvent assisted silk dyeing showed favorable results. Silk yarns showed better swelling properties in the DES than water. Process parameters such as temperature, time, and concentration of DES were optimized with the help of a design expert software. Lack of fit F-value and P-value of the ANOVA shows that the model is significant. Optimized solvent assisted silk dyeing was carried out with acid dye and found to be better than that of conventional dyeing in aqueous medium. DES assisted dyed silk fabric showed desired color strength at 60 °C for 37 min, which is 10 °C and 5–10 min lesser than the conventional dyeing of silk fabric. The percentage exhaustion of DES assisted dye bath was calculated and found to be good. DES assisted dyed silk fabric showed wash, light, and rubbing fastness properties comparable to conventional aqueous dyed silk fabric.

Control of Pore Size in Ordered Mesoporous Carbon-Silica by Hansen Solubility Parameters of Swelling Agent.

The cooperative assembly of functional precursors with block copolymers (BCPs) is a powerful, general route to fabricate ordered mesoporous materials, but the precise tuning of the mesopore size generally requires trial and error to obtain the correct BCP template or appropriate swelling agent. Here, we demonstrate the ability to effectively modulate both expansion and contraction of the ordered cylindrical mesopores relative to those obtained from cooperatively assembled Pluronic F127, resol, and tetraethylorthosilicate. The two key physical parameters for the swelling agents are their hydrophobicity, as quantified by the octanol-water partition coefficient (Kow), and Hansen solubility parameters that describe the interactions of the solvent with the different components of the BCP template. Four low volatility solvents are examined that span a wide Kow with up to 90 wt % solvent relative to the Pluronic F127. Glycerol triacetate (Kow < 1) can decrease the average mesopore size from 5.9 to 4.8 nm due to segmental screening of the interactions in the Pluronic F127 to decrease chain stretching at intermediate loadings. A modest increase in mesopore size to 8.1 nm can be achieved with trimethylbenzene (TMB, Kow = 3.42). Dioctyl phthalate (DOP), which is slightly more hydrophobic (Kow = 8.1), is more effective than TMB at expanding the pore size (maximum: 13.5 nm) without loss of ordered structure. A more hydrophobic solvent, tris (2-ethylhexyl) trimellitate (Kow = 12.5), is less effective at increasing the pore size (maximum: 8.2 nm). The Hansen solubility parameters for DOP most closely match those of the hydrophobic segment in the Pluronic F217 template. We attribute this similarity, which is related to the solvent quality, to the improved efficacy of DOP in increasing the pore size. These results illustrate that both the Hansen solubility parameters (relative to the hydrophobic segment of the template) and relative hydrophobicity of the swelling agent determine the obtainable pore sizes in cooperatively assembled ordered mesoporous materials.

Role of swelling agent and set-controlling admixtures on chloride binding and diffusion in cement matrix

Chloride binding and diffusion was investigated for cement matrix with swelling agent (SA), early-strength agent (ESA) and set-retarding agent (SRA). Chloride binding isotherms (CBIs), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and thermodynamic modeling were applied to quantitatively reveal the mechanisms of chloride binding. The current results indicate that ESA will reduce chloride binding capacity and enhance chloride diffusivity due to the competition between sulphate and chloride. SRA holds a reverse regularity on account of increasing long-term hydration degree. The role of SA combines with kaolin and gypsum, resulting in a slighter reduction of chloride binding capacity.

Not Just a Base, Use of “Swelling Agent” in a Claim for Emulsion Polymerization Patents: A Lesson from Organik Kimya AS v. Rohm & Haas Co.

Abstract Rohm & Haas Co. successfully defended the validity of their patents for manufacturing a core-shell polymer in Organik Kimya AS v. Rohm & Haas Co., 873 F.3d 887 (Fed. Cir. 2017). Relying on...

Enhancing the Dyeability of Polyimide Fibers with the Assistance of Swelling Agents.

Polyimide (PI) fibers have outstanding thermal stability and mechanical properties, but are difficult to dye with disperse and basic dyes. In this work, it was proposed to use N-methylformanilide (MFA), phenoxyisopropanol (PIP), and acetophenone (AP) as swelling agents to enhance the dyeability of PI fibers. The PI fibers treated with swelling agents were characterized by thermal gravimetric analysis, scanning electronic microscopy, tensile testing, and crystalline analysis. It was found that the swelling agents penetrated into the PI fibers in amounts greater than 10% (pertaining to the weight of PI fibers). The swelling agents did not really swell the PI fibers, but broke the interaction forces between the PI macromolecules. With the assistance of swelling agent, the PI fibers could be dyed with disperse and basic dyes in strong color strengths. AP exhibited the best performance for enhancing the dyeability of PI fibers, followed by MFA and PIP. The dyed PI fibers were found to have good colorfastness to washing.

Low-Vapor-Pressure Solvent Additives Function as Polymer Swelling Agents in Bulk Heterojunction Organic Photovoltaics

Bulk heterojunction (BHJ) photovoltaics based on blends of conjugated polymers and fullerenes require an optimized nanoscale morphology. Casting BHJ films using solvent additives such as 1,8-diiodooctane (DIO), 1,8-octanedithiol (ODT), chloronapthalene (CN), or diphenyl ether (DPE) often helps achieve this proper morphology: adding just a few volume percent of additive to the casting solution can improve polymer/fullerene mixing or phase separation, so that solvent additives have become staples in producing high-efficiency BHJ solar cells. The mechanism by which these additives improve BHJ morphology, however, is poorly understood. Here, we investigate how these additives control polymer/fullerene mixing by taking advantage of sequential processing (SqP), in which the polymer is deposited first and then the fullerene is intercalated into the polymer underlayer in a second processing step using a quasi-orthogonal solvent. In this way, SqP isolates the role of the additives’ interactions with the polymer an...

Swellable Organically Modified Silica (SOMS) as a Catalyst Scaffold for Catalytic Treatment of Water Contaminated with Trichloroethylene

The properties of a swellable organically modified silica (SOMS) scaffold allowed us to synthesize “smart” catalysts with tunable accessibility of the active sites induced by organic swelling agents. Pd nanoparticles (NPs) deposited inside the swollen matrix of SOMS were shown to be selectively located on the interior surface, a surface which is only available through swelling. Techniques such as near ambient-pressure X-ray photoelectron spectroscopy (NAP–XPS) and cryogenic scanning electron microscopy (SEM) were employed to characterize Pd/SOMS in its swollen as well as unswollen state because their conventional counterparts do not preserve the swollen state of Pd/SOMS during spectral acquisition. The results obtained depicted significant differences between the unswollen and swollen state of Pd/SOMS. The most important difference is that Pd NPs became accessible on the surface after exposure to an organic compound. This indicates that the accessibility of the active sites can be controlled by changing the reaction environment, hence allowing a tunable accessibility induced by organic swelling agents. The effects of the extent of swelling on the catalytic activity were investigated by performing catalytic activity experiments in the presence of an organic swelling agent. Hydrodechlorination (HDC) of trichloroethylene (TCE), an important method of catalytic water abatement, was chosen as a model reaction. The catalytic performance was found to be proportional to the concentration of the organic swelling agent, indicating that the accessibility of active sites is related to the concentration of organic compounds. While the unavoidable reaction product HCl inhibited the commonly used HDC catalyst 1%Pd/Al2O3, 1%Pd/SOMS was able to maintain its rate throughout the reaction under the same conditions, indicating its resistance to the inhibition. Overall, a silica-based catalyst with tunable accessibility of the active sites induced by changes in the reaction environment can have significant implications for heterogeneous catalysis.

Abnormal swelling of the peritrophic membrane in Eri silkworm gut caused by MLX56 family defense proteins with chitin-binding and extensin domains

MLX56 family defense proteins, MLX56 and its close homolog LA-b, are chitin-binding defense proteins found in mulberry latex that show strong growth-inhibitions against caterpillars when fed at concentrations as low as 0.01%. MLX56 family proteins contain a unique structure with an extensin domain surrounded by two hevein-like chitin-binding domains, but their defensive modes of action remain unclear. Here, we analyzed the effects of MLX56 family proteins on the peritrophic membrane (PM), a thin and soft membrane consisting of chitin that lines the midgut lumen of insects. We observed an abnormally thick (>1/5 the diameter of midgut) hard gel-like membrane consisted of chitin and MLX56 family proteins, MLX56 and LA-b, in the midgut of the Eri silkworms, Samia ricini, fed a diet containing MLX56 family proteins, MLX56 and LA-b. When polyoxin AL, a chitin-synthesis-inhibitor, was added to the diet containing MLX56 family proteins, the toxicity of MLX56 family proteins disappeared and PM became thinner and fragmented. These results suggest that MLX56 family proteins, through their chitin-binding domains, bind to the chitin framework of PM, then through their extensin-domain (gum arabic-like structure), which functions as swelling agent, expands PM into an abnormally thick membrane that inhibits the growth of insects. This study shows that MLX56 family proteins are plant defense lectins with a totally unique mode of action, and reveals the functions of extensin domains and arabinogalactan proteins as swelling (gel-forming) agents of plants.

Effect of a Swelling Agent on the Performance of Ni/Porous Silica Catalyst for CH4-CO2 Reforming.

Hierarchical porous materials are of great interest in various industrial applications because of their potential to overcome the mass transport limitations typically encountered for single-mode porous materials. This report describes the synthesis of a hierarchical trimodal porous silica-based material using a 7.5 molar ratio of a relatively inexpensive nonionic surfactant template, triblock copolymer P123, EO20PO70EO20. The pore size distribution curve shows the presence of three types of pores with average diameters of ∼8, 25, and 89 nm. Electron microscope images confirm the existence of smaller ordered mesopores (first mode), larger ordered mesopores (second mode), and macropores (third mode). Ni nanoparticles dispersed on this trimodal porous silica produce a material that exhibited excellent catalytic performance for the CO2 reforming of CH4. This research provides new insights that will facilitate the development of trimodal porous silica (TMS) materials for a variety of applications. The results demonstrated that the presence of large pores (second and third mode pores) in TMS material increased the number of accessible active Ni sites, which led to the high activity observed for Ni/TMS catalyst.

Effect of Cellulase Enzymes and Swelling Agents on Colour Strength and Colourfastness of Handloom Cotton Fabric Dyed with Butea Frondosa

Cellulases and swelling agents are known to be effective in improving the colour strength of cotton. Nowadays, handloom fabrics, such as khadi cotton, are much more preferred due to the development of innovative designs with their use and their comfort in wearing. Also, due to increased environmental awareness, the use of natural dyes are much more preferred in the dyeing of handloom fabrics. However, khadi cotton has some major shortcomings, such as less dyeability. The present study is carried out by keeping in mind that the pretreatment of khadi cotton with cellulases, swelling agents and a combination of cellulases and swelling agents before dyeing improves the colour strength properties. Khadi cotton samples are treated with optimized conditions of the enzymes and swelling agents. The optimum pH, concentration, treatment time and temperature selected for treatment of the samples with acid cellulase enzymes are 5.5, 1.5% (owf), 45 minutes and 50°C, respectively, whereas in the case of neutral cellulase enzymes, 7.5, 2.0% (owf), 70 minutes and 70°C, respectively. The optimum concentration, treatment time and temperature selected for the treatment of the samples with sodium hydroxide, ethylenediamine and zinc chloride are 20% w/v, 60 minutes and 60°C; 80% w/v, 60 minutes and 70°C, and 80% w/v, 60 minutes and 70°C respectively. Butea frondosa dye (5 g) extracted for 75 minutes provides the best results on khadi cotton when dyeing is carried out for 90 minutes. It is observed that out of the various concentrations of mordants used with the Butea frondosa dye, the best shades of colour are obtained by using 0.04 g of alum, 0.01 g of copper sulphate, and 5 g of Babool bark. In terms of optimizing the mordanting, the best results are obtained with Butea frondosa dye when the samples are simultaneously mordanted and dyed with alum, Babool bark and alum. Pre-mordanting is selected for the copper sulphate. It is found that for all the enzyme treated (acid and neutral cellulase) as well as swelling agent treated (sodium hydroxide, ethylenediamine and zinc chloride) samples, the colour strength and colourfastness increase in comparison to the untreated samples.

The Impact of Nonpolymerizable Swelling Agents On The Synthesis of Particles With Combined Geometric, Interfacial, and Compositional Anisotropy.

Seeded emulsion polymerization is by far the most successful synthetic method for making anisotropic particles with precise control and high throughput. However, this synthesis involves multiple steps and the types of anisotropic properties that have been made on particles are limited. Here, we demonstrate, by using two different types of nonpolymerizable swelling agents, that we can simplify this method while still producing colloidal dimers with combined anisotropic properties in geometry, interface, and composition. When we swell cross-linked polystyrene seed particles with a simple solvent toluene, without additional polymerization steps we can make dimers with asymmetric distribution of surface charges and roughness on two lobes by fast extraction of toluene. We further show that this toluene-swelling-extraction method can promote the surface modification of the second lobe selectively especially for hydrophilic and stimuli-responsive polymers, which was a significant challenge in dimer synthesis. When we change the swelling agent to a sol-gel precursor, that is, tetraethyl orthosilicate, we can make polystyrene-silica hybrid particles with different morphologies. Our method provides a facile synthetic platform for making colloidal particles with different types of anisotropic properties, which are expected to find important applications for colloidal surfactant, self-assembly, and artificial motors.

A Liming Process with Sodium Silicate Compound as a Swelling Agent

A Liming Process with Sodium Silicate Compound as a Swelling Agent

Beating Properties with Swelling agent and Concentration for Preparation of MicroFibrillated Cellulose (MFC)

ABSTRACT In this study, we evaluated properties of pulp treated with swelling agent and swelling concentration. We used swelling agent, such as NaOH, DMSO, urea. One of them, pulps treated with NaOH from 0 to 5% measured WRV, beating efficiency, crystallinity and as-pect ratio. We identified that NaOH when freeness reaches 100mL CSF was the shortest, on the other hand, WRV didn’t change. Because NaOH is good beating efficiency, when pulp treated with various concentration of NaOH from 0 to 5%, pulp treated 1% NaOH was best beating efficiency. However, WRV, crystalline structure and crystallinity didn’t change. The more NaOH concentration increased, the more aspect ratio increased, but when NaOH concentration exceeds 3%, aspect ratio decreased. As a result, pulp treated with 1% NaOH was the greatest beating efficiency and WRV, chemical structure didn’t change.Keywords: Microfibrillated cellulose (MFC), swelling agent, beating efficiency, WRV, crystallinity http://dx.doi.org/10.7584/ktappi.2015.47.3.003Journal of Korea TAPPIVol. 47. No. 3, 2015, 3-10pISSN(Print): 0253-3200Printed in Korea

Enlarged Pore Size in Mesoporous Silica Films Templated by Pluronic F127: Use of Poloxamer Mixtures and Increased Template/SiO2 Ratios in Materials Synthesized by Evaporation-Induced Self-Assembly

Although evaporation-induced self-assembly (EISA) has proven to be a convenient method for synthesizing nanoporous silica films (and particles), accessing material structures with pore sizes larger than ca. 10 nm remains experimentally inconvenient. The use of pore swelling agents (SAs), commonly used during the hydrothermal synthesis of mesoporous silicas, results in little or no pore size expansion due to evaporation or phase separation. Moreover, diblock copolymer templates can yield large pores but are quite expensive and generally require the addition of strong organic cosolvents. Here, we hypothesized that pores templated by the Pluronic triblock polymer F127 could be successfully enlarged, without phase separation, by using a chemically similar, nonvolatile, secondary Pluronic polymer (P103) as the SA. We find pore size increased up to 15 nm for a spherical pore morphology, with a phase transition to a multilamellar vesicle (MLV)-based nanostructure occurring as the P103/F127 ratio is further increased. This MLV phase produces even larger pore sizes due to the collapse of concentric silica shells upon template removal. Remarkably, F127 alone exhibits expansion of pore size (up to ca. 16 nm) as the template/silica ratio is increased. We find appearance of the MLV phase is due to geometric packing considerations, with expansion of F127 micelle size being a result of favorable intermolecular interactions driven by the large poly(ethylene oxide) content of F127. Other Pluronic polymers with this feature also exhibit variable pore size based on the template/silica ratio, enabling the synthesis of mesoporous films with 3D pore connectivity and truly variable pore size of ca. 4.5 to almost 20 nm.

Swelling agent adopted decal transfer method for membrane electrode assembly fabrication

The decal transfer method is regarded as an effective membrane electrode assembly (MEA) fabrication method for industrial processes due to the improved adhesion between the catalyst layers and the hydrocarbon membrane. In this study, three swelling agents (ethanol, 1,5-pentanediol and glycerol) are introduced to the conventional decal methods in order to improve both the transfer ratio of electrodes on the membrane surface and the electrochemical properties. These swelling agents affect the surface energy differences between the swollen catalyst layer and the membrane substrate. Swelling agents also change the structure of the catalyst layer during the preparation (hot pressing) of the MEA. Changing the catalyst layer structure by introducing swelling agents diminishes the charge transfer resistance and internal resistances of MEAs. These improved electrochemical properties lead to the remarkably enhanced single cell performance of a SPAES MEA of 1380mAcm−2 at 0.6V, compared to a SPAES MEA fabricated by the conventional decal method (500mAcm−2).

Ethylene‐bridged Periodic Mesoporous Organosilicas with Large Spherical Pores Templated by PEO‐PPO‐PEO Surfactant Micelles Swollen by Ethylbenzene

AbstractThe applicability of a recently identified potent micelle swelling agent, ethylbenzene, was verified for periodic mesoporous organosilicas (PMOs) and its performance was found to be comparable to that of xylene, which was previously shown to be an excellent swelling agent for surfactant‐templated ordered mesoporous silica and organosilica synthesis. Large‐pore ethylene‐bridged PMOs with face‐centered cubic structures of spherical mesopores were synthesized using Pluronic F127 (EO106PO70EO106) surfactant and ethylbenzene or xylene swelling agents at temperatures from 15 down to 7 °C. In the case of ethylbenzene, PMOs were synthesized at 15 °C using two different amounts of the inorganic salt (KCl) and under salt‐free conditions. It was found that ethylbenzene and xylene perform comparably well, allowing one to synthesize highly ordered face‐centered cubic ethylene‐bridged PMOs with unit‐cell parameters ca. 40 nm and nominal pore diameters ca. 14 nm. It was also possible to convert PMO prepared in the presence of ethylbenzene to silica with nearly closed mesopores via calcinations at 400 °C under air. The dependence of the PMO structure on the initial synthesis temperature and the salt concentration was found to be highly similar for ethylbenzene and xylene. Because of the fact that xylene (dimethylbenzene) was found earlier to work differently from toluene (methylbenzene) and trimethylbenzene, the observed similarity between the performance of xylene and ethylbenzene confirms an expectation that the suitability of alkylbenzenes for PEO‐PPO‐PEO block‐copolymer‐templated synthesis of well‐defined porous materials depends primarily on the total number of carbon atoms in their alkyl substituents. This finding is expected to streamline the process of identifying effective swelling agents for PMOs and other mesoporous materials.

Effect of Enzymes and Swelling Agents on Colour Strength (K/S) Property of Khadi Cotton Fabric Dyed With Sandalwood Dye: An Eco-friendly Approach

Cellulase and swelling agents are known to be effective in improving the colour strength of cotton. Nowadays, the handloom fabrics are much preferred due to development of innovative designs and their comfort in wearing. Interests in natural dyes are also growing throughout the world and people are becoming more aware of the need for eco-friendly materials to come up and dominate the harmful synthetic dyes. But, khadi cotton has some major shortcomings like less dyeability. Keeping in view that the pretreatment of khadi cotton with cellulases, swelling agents and combination of cellulases and swelling agents before dyeing improves the colour strength properties, the present study was planned. It was found that for all the enzyme treated (acid and neutral cellulase) as well as swelling agents treated (Sodium hydroxide, Ethylenediamine and Zinc chloride) samples, the colour strength was increased in comparison to the untreated samples