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Designing polymer structures and polymer blends opens opportunities to improve the performance of plastics. Blending poly(butylene adipate-co-terephthalate) (PBAT) and polylactide (PLA) is a cost-effective approach to achieve a new sustainable material with complementary properties. This study aimed to predict the theoretical miscibility of PBAT/PLA blends at the molecular level. First, the basic properties and the structure of PBAT and PLA are introduced, respectively. Second, using the group contribution methods of van Krevelen and Hoy, the Hansen and Hildebrand solubility parameters of PBAT and PLA were calculated, and the effect of the molar ratio of the monomers in PBAT on the miscibility with PLA was predicted. Third, the dependence of the molecular weight on the blend miscibility was simulated using the solubility parameters and Flory–Huggins theory. Next, the glass transition temperature of miscible PBAT/PLA blends, estimated using the Fox equation, is shown graphically. According to the prediction and simulation, the blends with a number-average molecular weight of 30 kg/mol for each component were thermodynamically miscible at 296 K and 463 K with the possibility of spinodal decomposition at 296 K and 30% volume fraction of PBAT. This study contributes to the strategic synthesis of PBAT and the development of miscible PBAT/PLA blends.

The Hildebrand solubility parameters and the Flory–Huggins interaction parameter of four 1-propyl-3-methylimidazolium ([C3mim]) based ionic liquids (ILs) with different anions ([NTf2], [BF4], [SCN] and [CF3CO2]) were investigated by inverse gas chromatography (IGC). The IGC characterization was carried out at temperatures ranging between 313.15 and 343.15 K. The Hansen solubility parameters (HSPs) of the four ILs were calculated using the Hansen Solubility Parameter in Practice software at T = 298.15 K. The Hildebrand solubility parameters of the four [C3mim]-based ILs were determined as δ2([C3mim][NTf2])  = 22.51 (MPa)0.5, δ2([C3mim][BF4])  = 23.15 (MPa)0.5, δ2([C3mim][SCN])  = 24.03 (MPa)0.5, and δ2([C3mim][CF3CO2])  = 26.81 (MPa)0.5 by extrapolation at 298.15 K. The HSPs at T = 298.15 K for the four ILs obtained by Hansen solubility sphere method show that δT([C3mim][NTf2])  = 21.70 (MPa)0.5, δT([C3mim][BF4])  = 22.78 (MPa)0.5, δT([C3mim][SCN])  = 23.49 (MPa)0.5 and δT([C3mim][CF3CO2])  = 26.06 (MPa)0.5. The results showed that the Hansen solubility sphere method provides the same tendency with the measurement results of IGC.

The compatibility between asphalt and nanosilica (nano-SiO 2 ) is critical to determine the performance of nano-SiO 2 –modified asphalt. However, a comprehensive understanding of the compatibility behavior and mechanism of asphalt components and nano-SiO 2 in the modified asphalt is still limited. In this study, the compatibility was revealed through molecular dynamics (MD) simulation. Virgin asphalt, nano-SiO 2 –modified asphalt, and oxidation aged asphalt models produced with the COMPASS force field; meanwhile, the proposed models were validated by comparisons with reference data. The compatibility of asphalt and nano-SiO 2 was analyzed by solubility and the Flory–Huggins parameters and interaction energy. Results show that the solubility parameters decreased with the increase of system temperature while increased with the asphalt’s oxidation level increase. Meanwhile, the compatibility of the asphaltene, resin, and aromatic components in asphalt is better than the compatibility with saturates, which may be due to saturates being volatile; however, the compatibility of the nano-SiO 2 and saturates is much better than those with asphaltene, resin, and aromatic components. The incorporation of nano-SiO 2 alleviates the volatilization of saturates. The present results provide insights into the understanding of the compatibility behavior and mechanism of nano-SiO 2 and asphalt components.

This paper describes the use Excel’s Solver of Microsoft and desirability function for the determination of Hansen’s solubility parameters (HSPs). The Excel’s solver is powerful while at the same time being user-friendly and easy to comprehend. Results of HSPs for different polymers and oils were evaluated and compared with the results obtained by the use of other tools; no significant differences were found between the Microsoft Excel solution and either the professional program HSPiP or other software platform used by different authors. Improvements introduced in the Excel book developed by Steven Abbott for this purpose, by the inclusion of some restrictions and functions, allow simultaneously optimizing the diameter of the Hansen sphere together with the determination of Hansen’s parameters, so that a tool, available to professional and researcher, can be used for these determinations with a high degree of precision, using any of the nonlinear optimization algorithms available in the Solver add-in. Finally, it is illustrated how the use of programming in Excel VBA can lead to a friendly interface for these determinations.

In recent years there has been a growing interest in formulating solid dispersions, which purposes mainly include solubility enhancement, sustained drug release and taste masking. The most notable problem by these dispersions is drug-carrier (in)solubility. Here we focus on solubility parameters as a tool for predicting the solubility of a drug in certain carriers. Solubility parameters were determined in two different ways: solely by using calculation methods, and by experimental approaches. Six different calculation methods were applied in order to calculate the solubility parameters of the drug ibuprofen and several excipients. However, we were not able to do so in the case of ibuprofen lysinate, as calculation models for salts are still not defined. Therefore, the extended Hansen’s approach and inverse gas chromatography (IGC) were used for evaluating of solubility parameters for ibuprofen lysinate. The obtained values of the total solubility parameter did not differ much between the two methods: by the extended Hansen’s approach it was δt = 31.15 MPa0.5 and with IGC it was δt = 35.17 MPa0.5. However, the values of partial solubility parameters, i.e., δd, δp and δh, did differ from each other, what might be due to the complex behaviour of a salt in the presence of various solvents.

Based on the solubility parameter theory, the Hansen solubility parameters of various solvents were calculated and compared to predict the solubility of cellulose in various solvents, which illustrates the feasibility of Hansen solubility parameters to predict the solubility of cellulose in solvents. This paper aims to make a more accurate prediction in advance when finding suitable cellulose solvent system, and then to reduce the burden of cellulose solvent selection.

The equilibrium swelling test was employed to determine the swelling response of Nitrile Butadiene Rubber (NBR) with various acrylonitrile (ACN) contents, and the three-dimensional solubility parameter (HSP) and modified Flory–Huggins interaction parameter (χHSP) were used to establish the prediction model of the oil-resistant property. The results indicate that the energy difference (Ra) between NBR and solvents calculated by HSP values can be correlated with the swelling response qualitatively with an inversed “S-shape”, and high swelling response occurs at Ra < 8 MPa1/2 for NBR. For the purpose of establishing the prediction model, the new modified χHSP value has been calculated and fitted with the swelling response using exponential and logarithmic fittings, respectively. Two prediction models considering all the possible influencing factors have been obtained to determine the swelling response and oil resistance of NBR-based rubber products in bio-fuels, represented by the bio-diesel and IRM 903 test oil in this work. The swelling response of NBR can be evaluated precisely, and high swelling regions can be predicted and avoided in the new emerging fuels through the prediction models. Thus, the oil resistance of NBR-based rubber products, such as seals, holes and gaskets can be well predicted now.

We recently introduced a straightforward method for determining the Hamaker constant for liquids using their Hansen solubility parameters. Our method is based on the relationship between the surface tension and the Hansen solubility parameters for liquids, as derived by Abbott, and the relationship between the surface tension and the Hamaker constant for liquids, as established by Israelachvili and revised by David and Neumann. In this paper, we demonstrate that this method is also applicable to polymers. For polymers, we use Murase and Nakamura’s formula for the surface tension/Hansen solubility parameter relationship in place of Abbott’s formula, along with Israelachvili’s formula for the corresponding surface tension/Hamaker constant relationship. Our approach for determining the Hamaker constant of polymers using their Hansen solubility parameters is shown to be generally valid for a wide range of polymers. Graphical Abstract

Purpose This paper aims to discuss the successful 3D printing of styrene–ethylene–butylene–styrene (SEBS) block copolymers using solvent-cast 3D printing (SC-3DP) technique. Design/methodology/approach Three different Kraton grade SEBS block copolymers were used to prepare viscous polymer solutions (ink) in three different solvents, namely, toluene, cyclopentane and tetrahydrofuran. Hansen solubility parameters (HSPs) were taken into account to understand the solvent–polymer interactions. Ultraviolet–visible spectroscopy was used to analyze transmittance behavior of different inks. Printability of ink samples was compared in terms of shape retention capability, solvent evaporation and shear viscosity. Dimensional deviations in 3D-printed parts were evaluated in terms of percentage shrinkage. Surface morphology of 3D-printed parts was investigated by scanning electron microscope. In addition, mechanical properties and rheology of the SC-3D-printed SEBS samples were also investigated. Findings HSP analysis revealed toluene to be the most suitable solvent for SC-3DP. Cyclopentane showed a strong preferential solubility toward the ethylene–butylene block. Microscopic surface cracks were present on tetrahydrofuran ink-based 3D-printed samples. SC-3D-printed samples exhibited high elongation at break (up to 2,200%) and low tension set (up to 9%). Practical implications SC-3DP proves to be an effective fabrication route for complex SEBS parts overcoming the challenges associated with fused deposition modeling. Originality/value To the best of authors’ knowledge, this is the first report investigating the effect of different solvents on physicomechanical properties of SC-3D-printed SEBS block copolymer samples.

The physicochemical properties of four 1-alkyl-3-methylimidazolium bromide ([CnC1im]Br, n = 5, 6, 7, 8) ionic liquids (ILs) were investigated in this work by using inverse gas chromatography (IGC) from 303.15 K to 343.15 K. Twenty-eight organic solvents were used to obtain the physicochemical properties between each IL and solvent via the IGC method, including the specific retention volume and the Flory–Huggins interaction parameter. The Hildebrand solubility parameters of the four [CnC1im]Br ILs were determined by linear extrapolation to be δ 2 ( [ C 5 C 1 im ] Br ) = 25.78 (J·cm−3)0.5, δ 2 ( [ C 6 C 1 im ] Br ) = 25.38 (J·cm−3)0.5, δ 2 ( [ C 7 C 1 im ] Br ) =24.78 (J·cm−3)0.5 and δ 2 ( [ C 8 C 1 im ] Br ) = 24.23 (J·cm−3)0.5 at room temperature (298.15 K). At the same time, the Hansen solubility parameters of the four [CnC1im]Br ILs were simulated by using the Hansen Solubility Parameter in Practice (HSPiP) at room temperature (298.15 K). The results were as follows: δ t ( [ C 5 C 1 im ] Br ) = 25.86 (J·cm−3)0.5, δ t ( [ C 6 C 1 im ] Br ) = 25.39 (J·cm−3)0.5, δ t ( [ C 7 C 1 im ] Br ) = 24.81 (J·cm−3)0.5 and δ t ( [ C 8 C 1 im ] Br ) = 24.33 (J·cm−3)0.5. These values were slightly higher than those obtained by the IGC method, but they only exhibited small errors, covering a range of 0.01 to 0.1 (J·cm−3)0.5. In addition, the miscibility between the IL and the probe was evaluated by IGC, and it exhibited a basic agreement with the HSPiP. This study confirms that the combination of the two methods can accurately calculate solubility parameters and select solvents.