Influence of the styrene content of thermoplastic styrene–butadiene rubbers in the effectiveness of the treatment with sulfuric acid

Zhu

J of Chemical Tech & Biotech

et al. 2016

BACKGROUND To invesigate the effect of pore structure on catalysis behavior, three sulfonated carbons with hierarchically ordered pores (SCHOP), mesopores (SMC), or micropores (SAC) were compared in conversion of fructose with 5‐hydroxymethyl furfural (5‐HMF). Fructose and 5‐HMF adsorption by three carbons with different pore structures were also measured. Kinetic modeling was employed to correlate the reaction and the adsorption data. RESULTS SEM characterization showed that SCHOP has hierarchical ordered macropores (about 220 nm in pore diameter) and mesopores (4.81 nm), whereas N2 adsorption desorption, EDS and –SO3H group determination suggested both its specific surface area and –SO3H group content were close to those of SMC but quite distinct in comparison with SAC. The fitted active energies of fructose dehydration over SCHOP, SMC and SAC by a pseudo‐first‐order kinetic model were 84.54, 62.88, and 61.42 kJ mol−1, respectively. CONCLUSION It was found that pore structure has a significant effect on catalytic activity and 5‐HMF selectivity. SCHOP was a highly efficient catalyst for fructose dehydration to 5‐HMF. Adsorption capacity measurement confirmed SCHOP favored the internal diffusion of both fructose and 5‐HMF due to its hierarchical ordered porous structure, and possessed more effective specific area for fructose but less for 5‐HMF. In the presence of SCHOP the rate‐determining step was chemical reaction, whereas in the case of SMC or SAC the effects of molecular internal diffusion were not negligible. As a result, SCHOP was superior to both SMC and SAC for fructose conversion and 5‐HMF selectivity. © 2016 Society of Chemical Industry

Section: Resultsmentioning

confidence: 98%

“…34 The characteristic bands at 1039 and 1180 cm −1 are assigned to stretching vibration of O = S = O bonds. 35 The vibration bands at 870 is C-H stretching in the phenyl group, and that at 1600 cm −1 is C = C stretching in the phenyl group. 36 These results verify the presence of -SO 3 H groups in the as-prepared carbon sulfonic acids.…”

Section: Resultsmentioning

confidence: 99%

Fructose dehydration to 5‐HMF over three sulfonated carbons: effect of different pore structures

Zhu

J of Chemical Tech & Biotech

et al. 2016

Proceedings of the Institution of Mechanical Engineers, Part L:

“…Each material requires the application of a specific surface treatment, as shown in Table 11. 19,52,60,62,[65][66][67][68][69][70][71][72] For example, Leather commonly has a layer of grease at the surface, which causes problems in the manufacture of the adhesive joint, thus the need to perform an adequate surface treatment. 63 The recommended surface treatment is to subject the leather to a mechanical treatment (roughening), using a P24 aluminium oxide abrasive cloth, to remove the presence of any greasy or fatty materials, like polyethylene that creates adhesion problems on the surface.…”

Section: Surface Treatmentsmentioning

confidence: 99%

“…The TR substrate must be subjected to a chemical treatment (halogenation) allowing reacting it to dry at least 1 hour at room temperature to improve material surface energy. 52,56,63,[67][68][69][70][71][72] Upper-to-sole bonding process…”

Section: Surface Treatmentsmentioning

confidence: 99%

Adhesives in the footwear industry

Paiva

Marques

Silva

et al. 2015

Footwear manufacturing is basically a process of transformation and assembly of various components made up of several materials where different adhesives play a key role, because without them, the shoe would lack shape and structure. This paper aims to understand the importance of adhesives in the footwear industry. It is necessary to identify the different processes in a shoemaking where adhesives are involved and the different adhesive joints produced, as well as their technical requirements. The adhesive joint performance will depend on the different adherends' nature used as footwear materials, the joint design, the surface treatments, the adhesive properties which depend on their formulation, and so on. Adhesive joints in a shoe act under different stress types (peel, shear, tensile, etc.). The most disfavourable are the peel stress. For that reason, the peel strength test is one of the most common to evaluate adhesive joints' performance. When heat resistance is an important adhesive requirements, a creep test is carried out. Furthermore, aging tests are undertaken in order to evaluate durability. This methodology is described in this paper. In the literature, one can find several papers on adhesives, specifically on their mechanical properties. However, there is little research related to footwear applications, including not only the mechanical properties that this industry demands, but also the composition of the adhesives. Therefore, this paper aims to connect the important mechanical properties for the footwear industry with the constituents of the adhesives. However, other properties are also important, such as viscosity, wettability, compatibility, etc., depending on the materials and the adhesive joint type.

“…FTIR spectra for titanaugite/ilmenite, NaOl and PSSNa, as well as titanaugite/ilmenite treated with PSSNa or NaOl, are shown in Figure 8a-c. It can be seen from the spectra of PSSNa that the signal of the hydroxyl peak in the sulfonate group opposite PSSNa emerges at 3425 cm −1 [21], the vibration peak of methylene -CH 2 on the benzene ring appeared at 2923 cm −1 [22], the peak for the stretching vibration of -C=C-appeared at 1636 cm −1 [23], and the peaks of stretching vibrations of O=S=O in -SO 3 H appeared at 1184 and 1129 cm −1 [24][25][26][27][28]. The bands at approximately 1402 and 1020 cm −1 were attributed to vibrations of benzene rings of PSSNa [29][30][31].…”

Section: Ftirmentioning

confidence: 99%

Novel Selective Depressant of Titanaugite and Implication for Ilmenite Flotation

et al. 2019

This paper studies the effects of sodium polystyrene sulfonate (PSSNa) used as a depressant upon the separation of ilmenite from titanaugite through flotation when sodium oleate (NaOl) is used as a collector by performing single mineral flotation experiments. The depression mechanism of PSSNa on titanaugite flotation was studied by electrokinetic potential and adsorbed amount measurements together with FTIR and XPS detection. Single mineral flotation experiments show that PSSNa is a selective depressant for the separation of ilmenite and titanaugite via flotation with NaOl as the collector. The results of the adsorbed amount tests show that the biggest distinction is in terms of the amount of NaOl adsorbed on the surfaces of ilmenite and titanaugite; the amount is expanded from 2.28 × 10 −7 to 9.34 × 10 −7 mol/m 2 when the dosage of PSSNa is 1 mg/L, as compared with no PSSNa, suggesting that PSSNa is a selective depressant when separating ilmenite and titanaugite through flotation. FTIR testing shows that chemisorption has occurred between the -SO 3 − groups of the molecular PSSNa and titanaugite surfaces. The results of further XPS testing reveal that PSSNa chemically interacts with Ca/Mg/Al/Fe on the titanaugite surface. The test results of FTIR in combination with XPS confirm that PSSNa stops NaOl from interacting with Mg, Fe, Al, and Ca on the titanaugite surface, and this outcome is the main reason for the widening of the adsorption quantity gap of NaOl on titanaugite and ilmenite surfaces, and titanaugite flotation is suppressed. The results of the comparison flotation testing on actual Panzhihua titanic iron ore (TiO 2 grade: 15.63%) with titanaugite as the main gangue show that a better effect is obtained by replacing sodium silicate (SS) with PSSNa, and the recovery of TiO 2 using PSSNa is higher than that when using sodium silicate. In a closed circuit flotation test, ilmenite concentrate is obtained with a TiO 2 grade of 45.97% and a recovery of 76.32% by using PSSNa as a titanaugite depressant.