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Cosolvent-free (solventless) hydrolytic polycondensation of fluoroalkyltrimethoxysilanes of linear fluoroalkyl groups of the form R = CFCH ( = 1, 4, and 8) and methyltrimethoxysilane followed by thermal curing yielded dense polymeric silsesquioxane (SQ) resins with low refractive indices and deep-ultraviolet transparency with an ultraviolet absorption edge at ∼210 nm. The refractive index at 589 nm was adjustable at ∼1.35-1.39, and the lowest value was ∼1.354 for the stiff resin and ∼1.347 for the soft resin of poly(R--Me-SQ) prepared at = 8. The refractive indices of these resins were consistent with the linear combinations of molar refractivities of constituent functional groups, and there were no free-volume anomalies.
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http://dx.doi.org/10.1021/acs.jpcb.1c04308 | DOI Listing |
Bioresour Technol
September 2025
College of Engineering, Huazhong Agricultural University, Wuhan 430070, China. Electronic address:
In response to the challenges of nutrient limitations and low efficiency in synthesizing artificial humic acid (AHA) during the resource utilization of agricultural wastes, this study innovatively developed a process that integrates biogas slurry (BS) impregnation pretreatment with hydrothermal humification (HTH). Using steam-exploded corn straw (SES) as the raw material, the impregnation parameters were optimized (40 °C, liquid-to-solid ratio of 15:1, 18 h, 3 cycles), achieving an AHA yield of 40.61 %, which was over 15 % higher than that of the untreated group.
View Article and Find Full Text PDFPolymers (Basel)
July 2025
Enikolopov Institute of Synthetic Polymeric Materials, Russian Academy of Sciences (ISPM RAS), Profsoyuznaya Str. 70, Moscow 117393, Russia.
Polysodiumoxy(methyl)siloxane is a highly functional polymer matrix that can be used for the preparation of both functional and non-functional polymers, including molecular brushes. To determine the molecular weight parameters of the matrix, as well as its chemical structure, it is necessary to develop an effective method of blocking functional (in our case, sodiumoxy) groups due to their high reactivity. At the same time, the blocking product should represent a complete non-functionalized replica of polysodiumoxy(methyl)siloxane.
View Article and Find Full Text PDFInt J Mol Sci
July 2025
Department of Civil, Chemical, Environmental, and Materials Engineering, University of Bologna, Via Terracini 28, 40131 Bologna, Italy.
Cardiovascular diseases are responsible for a large number of severe disability cases and deaths worldwide. Strong research in this field has been extensively carried out, in particular for the associated complications, such as the occlusion of small-diameter (<6 mm) vessels. Accordingly, in the present research, two random copolyesters of poly(butylene 2,5-furandicarboxylate) (PBF) and poly(butylene isophthalate) (PBI), were successfully synthesized via two-step melt polycondensation and were thoroughly characterized from molecular, thermal, and mechanical perspectives.
View Article and Find Full Text PDFMaterials (Basel)
April 2025
Faculty of Materials Science and Ceramics, AGH University of Krakow, al. Mickiewicza 30, 30-059 Kraków, Poland.
Boron-modified ceramic materials derived from polymers (PDC) are the subject of this research. The primary objective is to compare the structure and microstructure of SiBOC materials obtained in varying pyrolysis conditions in comparison to base SiOC materials. The preparation involved a number of stages, staring with the hydrolytic polycondensation method, followed by the initial thermal treatment and the final stage-pyrolysis process in argon or argon/hydrogen atmospheres at different temperatures.
View Article and Find Full Text PDFPolymers (Basel)
January 2025
A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, 29 Leninsky Prospekt, 119991 Moscow, Russia.
The paper describes changes in the structure, morphology, mechanical and thermal properties of porous film samples of poly(4,4'-oxidiphenylene)pyromellitimide prepared as a result of selective destruction of urethane blocks in copolymers composed of pyromellitimide blocks and polyurethane blocks. The initial samples of the new composition of statistical copoly(urethane-imide)s (CoPUIs) were prepared via polycondensation methods using pyromellitic dianhydride (PMDA), 4,4'-oxidyaniline (ODA), 2,4-toluylenediisocyanate (TDI), as well as polycaprolactone (PCL) and poly(1,6-hexanediol/neopentylglycol-alt-adipic acid) (ALT) as monomers. The molar ratio of imide and polyurethane blocks in CoPUI was 10:1.
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