Determination of Sequence Distribution in Styrene-Butadiene Copolymer I. 1H-NMR Study of Styrene Oligomers

1981 ◽  
Vol 54 (4) ◽  
pp. 685-691 ◽  
Author(s):  
Y. Tanaka ◽  
H. Sato ◽  
K. Saito ◽  
K. Miyashita
Keyword(s):  
Relative Intensity ◽  
Methine Proton ◽  
Degree Of Polymerization ◽  
Sequence Length ◽  
Methylene Proton ◽  
Nmr Study ◽  
Average Sequence Length ◽  
Phenyl Proton ◽  
Two Peaks ◽  
Styrene Butadiene

Abstract The 1 H-NMR spectra of styrene oligomers were measured as a model of styrene sequences in SBR. The ortho-phenyl proton, methine proton, and methylene proton signals shift to a higher magnetic field as the degree of polymerization increased. The methine proton signal split into two peaks, reflecting the tacticity. The methylene proton flanked by methylene and methine protons had a higher chemical shift value than the methylene proton flanked by two methine protons. It is demonstrated that the average sequence length of the styrene units in SBR can be determined by the relative intensity ratio of the two methylene proton signals. It is also found that the fraction of styrene sequences longer than 6 units can be estimated from the relative intensity of ortho-phenyl proton signals resonated higher than 6.7 ppm.

1H NMR Study of Polyisoprenes

1980 ◽  
Vol 53 (2) ◽  
pp. 305-312 ◽  
Author(s):  
H. Sato ◽  
Y. Tanaka
Keyword(s):  
1H Nmr ◽  
Nmr Spectra ◽  
Methine Proton ◽  
Broad Peak ◽  
Methylene Proton ◽  
Methyl Proton ◽  
Nmr Study ◽  
In Cis ◽  
Methylene Proton Signal

Abstract 1H NMR spectra of polyisoprene were assigned using polymers of isoprene-1,1,4,4-d4, isoprene-1,1,5,5,5-d5, and isoprene-4,4-d2 polymerized with various catalysts. The methylene-proton signal at 2.1 ppm in cis-1,4- and trans-1,4-polyisoprenes was divided into H4- and H1-proton signals; H4 resonated at 2.21 ppm in both cis-1,4 and trans-1,4 units, whereas H1 resonated at 2.05, 2.21, and 2.15 ppm. Splitting due to the dyad sequences of 1,4 and 3,4 units was apparent. The methine-proton (H3) in a 3,4 unit showed a broad peak centered around 1.5 ppm in C6D6. The overlapping of this signal with the methyl-proton signals at 1.73 and 1.63 ppm resulted in some uncertainty in the determination of the microstructure of polyisoprene which contained a considerable amount of 3,4 unit.

NMR study of styrene-butadiene rubber (SBR) and TiO2 nanocomposites

2009 ◽  
Vol 28 (5) ◽  
pp. 490-494 ◽  
Author(s):  
Tatiane M. Arantes ◽  
Katyuscya V. Leão ◽  
Maria Inês B. Tavares ◽  
Antonio Gilberto Ferreira ◽  
Elson Longo ◽  
...  
Keyword(s):  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Nmr Study ◽  
Styrene Butadiene

Studies on the PMR Spectra of Oxetanes. VI 2-(3-Chlorophenyl)oxetane and 2-(2-Chlorophenyl)oxetane at 60 and 100 MHz

1974 ◽  
Vol 29 (12) ◽  
pp. 1902-1906 ◽  
Author(s):  
Jukka Jokisaari
Keyword(s):  
Long Range ◽  
Chemical Shifts ◽  
Methine Proton ◽  
Coupling Constants ◽  
Coupling Constant ◽  
Proton Proton ◽  
Temperature Range ◽  
Proton Coupling ◽  
Phenyl Proton ◽  
Pmr Spectra

The 100 MHz spectra of the phenyl protons in 2-(3-chlorophenyl) oxetane and 2-(2-chlorophenyl) oxetane have been analysed. The 60 MHz PMR chemical shifts and proton-proton coupling constants have been studied in the temperature range from -20 C to +80 °C. The chemical shifts were sensitive to temperature, while the coupling constants were not, except the long range 5Jm coupling constant between the methine proton and the meta positioned phenyl proton in 2-(2-chlorophenyl) oxetane.

scholarly journals NMR STUDY OF THE OXIDATIVE CHLOROPHOSPHORYLATION OF STYRENE–BUTADIENE RUBBER

2019 ◽  
pp. 20-24
Author(s):  
N.A. Efendiyeva ◽  
◽  
A.M. Maharramov ◽  
A.A. Azizov ◽  
A.Y. Melikova ◽  
...  
Keyword(s):  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Nmr Study ◽  
Styrene Butadiene

scholarly journals Synthesis, Characterization, and Aqueous Properties of an Amphiphilic Terpolymer with a Novel Nonionic Surfmer

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Qin Yu ◽  
Xiaolin Wu ◽  
Yanqiu Li ◽  
Tenglong Gao ◽  
Siliang Liu ◽  
...  
Keyword(s):  
Surface Activity ◽  
Oil Recovery ◽  
Mixed Micelles ◽  
Polymer Surface ◽  
Active Agent ◽  
Hydrophobic Association ◽  
Sequence Length ◽  
Sodium Acrylate ◽  
Average Sequence Length ◽  
Average Sequence

A series of surfactive amphiphilic polymer PAADs were prepared from the copolymerization of sodium acrylate, dodecyl polyoxyethylene acrylate (DPA, a surfmer), and acrylamide under the action of a mixed initiating agent consisting of ammonium persulfate-sodium bisulfite/2,2′-azobis[2-(2-imidazolin-2-yl) propane] dihydrochloride. The aggregative behaviors of PAADs were explored by 13C nuclear magnetic resonance, a viscometer, and a surface tension instrument. It was found that the apparent viscosity and surface activity of PAADs were significantly improved by the increase of average sequence length of hydrophobic micro blocks, strong intermolecular hydrophobic association, or the formation of mixed micelles between hydrophobic micro blocks and micromolecular surface-active agent. The introduction of long-chain alkyls on molecular chains prolonged the average sequence length of hydrophobic micro blocks in molecular chains and enhanced the hydrophobic association between molecular chains and the tight arrangement of molecular chains on water surfaces, thereby increasing the surface activity. Moreover, the anionic monomer sodium acrylate on molecular chains, via electrostatic repulsion, promoted the conversion from intrachain association to intermolecular association and thereby facilitated the formation of dense interfacial films, enhancing the surface activity of water solutions. Then, the anion surfmer sodium dodecylbenzenesulfonate interacted with the hydrophobic micro blocks on the molecular chains to form mixed micelles, which accelerated the interchain association and enhanced the polymer surface activity. The novel polymeric micelle with higher viscosifying ability and surface activity was expected to be a promising oil drive agent for tertiary oil recovery.

Holo-Transcriptome Sequences from the Tropical Marine Sponge Cinachyrella alloclada

2021 ◽  
Author(s):  
Yvain Desplat ◽  
Jacob F Warner ◽  
Jose V Lopez
Keyword(s):  
Marine Sponge ◽  
High Throughput Sequencing ◽  
Gc Content ◽  
Model Organism ◽  
Sequence Length ◽  
Microbial Abundance ◽  
Average Sequence Length ◽  
The Common ◽  
Transcriptome Sequences ◽  
Average Sequence

Abstract Marine sponge transcriptomes are underrepresented in current databases. Furthermore, only two sponge genomes are available for comparative studies. Here we present the assembled and annotated holo-transcriptome of the common Florida reef sponge from the species Cinachyrella alloclada. After Illumina high throughput sequencing, the data assembled using Trinity v2.5 confirmed a highly symbiotic organism, with the complexity of high microbial abundance (HMA) sponges. This dataset is enriched in poly-A selected eukaryotic, rather than microbial transcripts. Overall, 39,813 transcripts with verified sponge sequence homology coded for 8,496 unique proteins. The average sequence length was found to be 946 bp with an N50 sequence length of 1290 bp. Overall, the sponge assembly resulted in a GC content of 51.04%, which is within the range of GC bases in a eukaryotic transcriptome. BUSCO scored completeness analysis revealed a completeness of 60.3% and 60.1% based on the Eukaryota and Metazoa databases, respectively. Overall, this study points to an overarching goal of developing the Cinachyrella alloclada sponge as a useful new experimental model organism.

NMR study into the mechanism of recognition of the degree of polymerization by oligo/polysialic acid antibodies

2013 ◽  
Vol 21 (19) ◽  
pp. 6069-6076 ◽  
Author(s):  
Shinya Hanashima ◽  
Chihiro Sato ◽  
Hiroshi Tanaka ◽  
Takashi Takahashi ◽  
Ken Kitajima ◽  
...  
Keyword(s):  
Polysialic Acid ◽  
Degree Of Polymerization ◽  
Nmr Study ◽  
Mechanism Of Recognition

A compilation of soybean ESTs: generation and analysis

Genome ◽  
2002 ◽  
Vol 45 (2) ◽  
pp. 329-338 ◽  
Author(s):  
Randy Shoemaker ◽  
Paul Keim ◽  
Lila Vodkin ◽  
Ernest Retzel ◽  
Sandra W Clifton ◽  
...  
Keyword(s):  
Genome Sequencing ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Cdna Libraries ◽  
Sequence Length ◽  
Valuable Insight ◽  
Alternative Approach ◽  
Average Sequence Length ◽  
Expressed Sequence ◽  
Insight Into

Whole-genome sequencing is fundamental to understanding the genetic composition of an organism. Given the size and complexity of the soybean genome, an alternative approach is targeted random-gene sequencing, which provides an immediate and productive method of gene discovery. In this study, more than 120 000 soybean expressed sequence tags (ESTs) generated from more than 50 cDNA libraries were evaluated. These ESTs coalesced into 16 928 contigs and 17 336 singletons. On average, each contig was composed of 6 ESTs and spanned 788 bases. The average sequence length submitted to dbEST was 414 bases. Using only those libraries generating more than 800 ESTs each and only those contigs with 10 or more ESTs each, correlated patterns of gene expression among libraries and genes were discerned. Two-dimensional qualitative representations of contig and library similarities were generated based on expression profiles. Genes with similar expression patterns and, potentially, similar functions were identified. These studies provide a rich source of publicly available gene sequences as well as valuable insight into the structure, function, and evolution of a model crop legume genome.Key words: Glycine max, genome sequencing, functional genomics.

Relationship between Sequence Length and Thermal Properties of Poly(ethylene Terephthalate-Co-4, 4’-Bibenzoate) (PETBB)

2012 ◽  
Vol 476-478 ◽  
pp. 2243-2247
Author(s):  
Jian Ming Jiang ◽  
Jun Ming Dai ◽  
Sheng Lin Yang ◽  
Guang Li
Keyword(s):  
Chemical Composition ◽  
Melting Temperature ◽  
Ethylene Terephthalate ◽  
Feed Ratio ◽  
Sequence Length ◽  
Poly Ethylene Terephthalate ◽  
Average Sequence Length ◽  
Average Sequence ◽  
Poly Ethylene ◽  
High Level

Poly(ethylene terephthalate-co-4,4’-bibenzoate)s (PETBBs) with 0-25mol% bibenzoate unit were prepared from terephthalic acid (PTA), 4,4'- bibenzoic acid (BBA) and ethylene glycol (EG). The chemical composition and number-average sequence length of the resultant PETBBs were investigated by 13C-NMR. It was improved that the chemical composition of PETBBs is identical with the feed ratio, and the number-average sequence length of PET segment (LPET) becomes reduced with increasing BBA unit. The molecular weights of PETBBs reaches the high level for practical use. DSC analysis explains that the glass transition temperature (Tg) increases almost linearly and the crystallization becomes difficulty with increasing content of BBA unit. X-ray diffraction also illustrates that both crystallinity and crystal size reduced as more BBA unit is incorporated. Moreover, the relationship between the number-average sequence length and the melting temperature was investigated. The linear correlation between the number-average sequence length (LPET) and the melting temperature was observed.

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