Low-molecular-weight styrene–butadiene copolymers (L-SSBR) as processing aids used for silica-filled rubber: Synthesis, functionalization and application

2018 ◽  
Vol 51 (3) ◽  
pp. 244-261
Author(s):  
Barbara Robak ◽  
Jarosław Rogoża ◽  
Mieczysław Łapkowski
Keyword(s):  
Molecular Weight ◽  
Functional Groups ◽  
Gel Permeation Chromatography ◽  
Proton Nuclear Magnetic Resonance ◽  
Low Molecular Weight ◽  
Nuclear Magnetic Resonance Analysis ◽  
Resonance Analysis ◽  
Filled Rubber ◽  
Cure Characteristic ◽  
Styrene Butadiene

Three different types of low-molecular-weight solution styrene-butadiene rubbers (L-SSBRs) were synthesized by anionic polymerization. Two of them were end-capped with methoxy (M-L-SSBR) and ethoxy (E-L-SSBR) functional groups, respectively, while the other was terminated with alcohol (L-SSBR). The content of functional groups was estimated on the basis of gel permeation chromatography and proton nuclear magnetic resonance analysis. The influence of L-SSBR on the properties of silica-filled SSBR as an alternative for the plasticizing oil was investigated in tyre tread formulation. L-SSBRs of high vinyl content were used in place of part of oil for preparation of compound K1 enriched with linear (L-SSBR) and compound K2 and K3 enriched with two star-like liquid rubbers modified, respectively, with methoxy (M-L-SSBR) and ethoxy (E-L-SSBR) functional groups. Although particular attention was paid to the effect of polar groups on the silica dispersions, cure characteristic, compound viscosity and mechanical properties were also analyzed. Rubber with only treated distillate aromatic extract was used (K5) as the reference.

scholarly journals Synthesis of a Low-Molecular-Weight Form of Exopolysaccharide by Bradyrhizobium japonicum USDA 110

2001 ◽  
Vol 67 (2) ◽  
pp. 1011-1014 ◽  
Author(s):  
Heather A. Louch ◽  
Karen J. Miller
Keyword(s):  
Molecular Weight ◽  
Bradyrhizobium Japonicum ◽  
Compositional Analysis ◽  
Mass Spectrometry Analysis ◽  
Low Molecular Weight ◽  
Nuclear Magnetic Resonance Analysis ◽  
Spectrometry Analysis ◽  
Resonance Analysis ◽  
Dimeric Form ◽  
Molecular Weight Form

ABSTRACT A novel extracellular low-molecular-weight polysaccharide was detected as a contaminant within extracellular cyclic β-1,6-β-1,3-glucan preparations from Bradyrhizobium japonicum USDA 110 cultures. Compositional analysis, methylation analysis, and nuclear magnetic resonance analysis revealed that this low-molecular-weight polysaccharide was composed of the same pentasaccharide repeating unit previously described for the high-molecular-weight form of the exopolysaccharide (EPS) synthesized by B. japonicum strains. Mass spectrometry analysis indicated that the size of this low-molecular-weight form of EPS was consistent with a dimeric form of the pentasaccharide repeating unit.

scholarly journals Alcoholytic Cleavage of Polyhydroxyalkanoate Chains by Class IV Synthases Induced by Endogenous and Exogenous Ethanol

2013 ◽  
Vol 80 (4) ◽  
pp. 1421-1429 ◽  
Author(s):  
Manami Hyakutake ◽  
Satoshi Tomizawa ◽  
Kouhei Mizuno ◽  
Hideki Abe ◽  
Takeharu Tsuge
Keyword(s):  
Molecular Weight ◽  
Pha Synthase ◽  
Low Molecular Weight ◽  
Nuclear Magnetic Resonance Analysis ◽  
Content Type ◽  
Resonance Analysis ◽  
Inherent Feature ◽  
Class Iv

ABSTRACTPolyhydroxyalkanoate (PHA)-producingBacillusstrains express class IV PHA synthase, which is composed of the subunits PhaR and PhaC. RecombinantEscherichia coliexpressing PHA synthase fromBacillus cereusstrain YB-4 (PhaRCYB-4) showed an unusual reduction of the molecular weight of PHA produced during the stationary phase of growth. Nuclear magnetic resonance analysis of the low-molecular-weight PHA revealed that its carboxy end structure was capped by ethanol, suggesting that the molecular weight reduction was the result of alcoholytic cleavage of PHA chains by PhaRCYB-4induced by endogenous ethanol. This scission reaction was also induced by exogenous ethanol in bothin vivoandin vitroassays. In addition, PhaRCYB-4was observed to have alcoholysis activity for PHA chains synthesized by other synthases. The PHA synthase fromBacillus megaterium(PhaRCBm) from another subgroup of class IV synthases was also assayed and was shown to have weak alcoholysis activity for PHA chains. These results suggest that class IV synthases may commonly share alcoholysis activity as an inherent feature.

Alternative Tanning Agent for Leather Industry from a Sustainable Source

2021 ◽  
Vol 116 (3) ◽  
Author(s):  
Cigdem Kilicarislan Ozkan ◽  
Hasan Ozgunay
Keyword(s):  
Molecular Weight ◽  
Corn Starch ◽  
Periodate Oxidation ◽  
Gel Permeation Chromatography ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
Leather Industry ◽  
Sodium Metaperiodate ◽  
Gel Permeation ◽  
Aldehyde Content

Dialdehyde starches with different aldehyde content from native corn starch were prepared by sodium periodate oxidation to be used as a tanning agent in leather making. For this purpose, native corn starch was oxidized with sodium metaperiodate in different molar ratios. After oxidation processes, the yields, solubility in water and aldehyde contents of the obtained dialdehyde starches were determined as well as structure characterizations by Proton Nuclear Magnetic Resonance Spectroscopy, Fourier Transform Infrared Spectroscopy and Gel Permeation Chromatography. Evaluating the gel permeation chromatography data, the dialdehyde starch samples which were thought to be in appropriate molecular weight/size to penetrate into skin fibers were selected to be used in the tanning process. Their tanning abilities were evaluated by investigating hydrothermal stabilities, filling and fiber isolation characteristics and physical properties determined by mechanical tests and organoleptically. From the evaluation of the results, it was revealed that sodium metaperiodate oxidized starches which have appropriate molecular weight and adequate aldehyde content has a remarkable tanning effect and can be utilized as a tanning agent with the advantages of not necessitating pickling process which means saving time and simplifying the production but more importantly offering an important advantage from an environmental point of view.

scholarly journals Characterisation of Sequential Solvent Fractionation and Base-catalysed Depolymerisation of Treated Alkali Lignin

BioResources ◽  
2015 ◽  
Vol 10 (3) ◽  
pp. 4137-4151 ◽  
Author(s):  
Aikfei Ang ◽  
Zaidon Ashaari ◽  
Edi Suhaimi Bakar ◽  
Nor Azowa Ibrahim
Keyword(s):  
Molecular Weight ◽  
Chemical Structure ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Solubility Parameters ◽  
Low Molecular Weight ◽  
Sequential Fractionation ◽  
Weight Average Molecular Weight ◽  
Solvent Fractionation ◽  
Alkali Lignin

An alkali lignin (OL) with a weight-average molecular weight (Mw) of 11646 g/mol was used to prepare low-molecular weight lignin for resin synthesis. The low-molecular weight lignin feedstock was obtained via base-catalysed depolymerisation (BCD) treatments at different combined severity factors. Sequential fractionation of the OL and BCD-treated lignins using organic solvents with different Hildebrand solubility parameters were used to alter the homogeneity of the OL. The yield and properties of OL itself and OL and BCD-treated OL dissolved in propan-1-ol (F1), ethanol (F2), and methanol (F3) were determined. Regardless of the treatment applied, a small amount of OL was dissolved in F1 and F2. The BCD treatment did not increase the yield of F1 but did increase the yields of F2 and F3. Gel permeation chromatography (GPC) showed that the repolymerization reaction occurred in F3 for all BCD-treated OL, so these lignins were not suitable for use as feedstocks for resin production. The GPC, 13Carbon-nuclear magnetic resonance, and Fourier transform infrared spectroscopy analyses confirmed that the F3 in OL exhibited the optimum yield, molecular weight distribution, and chemical structure suitable for use as feedstocks for resin synthesis.

scholarly journals Microwave-Assisted Catalytic Synthesis of Bio-Based Copolymers from Waste Cooking Oil

2017 ◽  
Author(s):  
Mahrzadi Noureen Shahi ◽  
Muhammad Arshad ◽  
Aman Ullah
Keyword(s):  
Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Waste Cooking Oil ◽  
Attenuated Total Reflection ◽  
Fatty Acid Esters ◽  
Proton Nuclear Magnetic Resonance ◽  
Co Catalyst ◽  
Cooking Oil ◽  
First Time ◽  
Acid Esters

Solvent free copolymerization of epoxides derived from fatty acid esters of waste cooking oil with phthalic anhydride using (salen)CrIII Cl as catalyst and n-Bu4NCl/DMAP as co-catalyst was carried out for the first time under microwave irradiation, where reaction time was reduced from number of hours to minutes. The polyesters were obtained with molecular weight (Mw = 3084-6740 g/mol) and dispersity values (D = 1.18-1.92), when (salen)CrIII Cl/n-Bu4NCl was used as catalysts. While in case of DMAP as a co-catalyst, polyesters with improved molecular weight (Mw = 5537-6925 g/mol) and narrow dispersity values (D = 1.07-1.28) were obtained even at reduced concentrations of (salen)CrIII Cl and DMAP. The obtained products were characterized and evaluated by attenuated total reflection-fourier transform infrared spectroscopy (ATR-FTIR), proton nuclear magnetic resonance (1H-NMR) spectroscopy, gel permeation chromatography (GPC) and thermogravimetric analysis (TGA) Techniques.

scholarly journals Hybrid Interface in Sepiolite Rubber Nanocomposites: Role of Self-Assembled Nanostructure in Controlling Dissipative Phenomena

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 486 ◽  
Author(s):  
Elkid Cobani ◽  
Irene Tagliaro ◽  
Marco Geppi ◽  
Luca Giannini ◽  
Philippe Leclère ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Rubber Matrix ◽  
Styrene Butadiene Rubber ◽  
Nuclear Magnetic Resonance Analysis ◽  
Butadiene Rubber ◽  
Resonance Analysis ◽  
Self Assembled ◽  
Styrene Butadiene ◽  
The Impact

Sepiolite (Sep)–styrene butadiene rubber (SBR) nanocomposites were prepared by using nano-sized sepiolite (NS-SepS9) fibers, obtained by applying a controlled surface acid treatment, also in the presence of a silane coupling agent (NS-SilSepS9). Sep/SBR nanocomposites were used as a model to study the influence of the modified sepiolite filler on the formation of immobilized rubber at the clay-rubber interface and the role of a self-assembled nanostructure in tuning the mechanical properties. A detailed investigation at the macro and nanoscale of such self-assembled structures was performed in terms of the organization and networking of Sep fibers in the rubber matrix, the nature of both the filler–filler and filler–rubber interactions, and the impact of these features on the reduced dissipative phenomena. An integrated multi-technique approach, based on dynamic measurements, nuclear magnetic resonance analysis, and morphological investigation, assessed that the macroscopic mechanical properties of clay nanocomposites can be remarkably enhanced by self-assembled filler structures, whose formation can be favored by manipulating the chemistry at the hybrid interfaces between the clay particles and the polymers.

scholarly journals Fractionation of lignosulphonates released during the early stages of delignification

1983 ◽  
Vol 61 (2) ◽  
pp. 416-420 ◽  
Author(s):  
Norman G. Lewis ◽  
David A. I. Goring ◽  
Alfred Wong
Keyword(s):  
Molecular Weight ◽  
High Performance ◽  
Black Spruce ◽  
Gel Permeation Chromatography ◽  
Bimodal Distribution ◽  
High Yield ◽  
Low Molecular Weight ◽  
Lower Yield ◽  
Spruce Wood ◽  
Gel Permeation

High-yield spent bisulphite liquor (HY-SBL) from sulphonated black spruce wood (Piceamariana) was fractionated by gel permeation chromatography (GPC) and by high-performance liquid chromatography (HPLC). The GPC fractionation gave a wide bimodal distribution, whereas with HPLC, a more detailed resolution was seen with the bulk of the fraction giving several clearly defined peaks. The paucidisperse material was further concentrated by a bulk fractionation of the crude SBL which included complexing the lignosulphonates with dicyclohexylamine. The isolated paucidisperse material was found to be dialyzable and to constitute 90% of the lignosulphonate in the sample of SBL. If the bisulphite pulp obtained was recooked in fresh acid sulphite liquor to a lower yield, most of the lignosulphonate dissolved was widely polydisperse with no indication of the discrete components resolvable by HPLC. However, 25% of the lignin made soluble was in the form of the paucidisperse fractions. In all, we were able to obtain about 50% of the lignin in spruce wood as a relatively low molecular weight lignosulphonate resolvable into discrete fractions by HPLC.

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