Structure of the molecular-weight regulator and the mechanism of the depolyamidation of polycaproamide

1979 ◽  
Vol 11 (1) ◽  
pp. 1-7
Author(s):  
L. N. Mizerovskii ◽  
Yu. M. Bazarov
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Regulator

scholarly journals Prediction of the Styrene Butadiene Rubber Performance by Emulsion Polymerization Using Backpropagation Neural Network

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Yan-jiang Jin ◽  
Ben-xian Shen ◽  
Ruo-fan Ren ◽  
Lei Yang ◽  
Jun Sui ◽  
...  
Keyword(s):  
Neural Network ◽  
Molecular Weight ◽  
National Standard ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Backpropagation Neural Network ◽  
Marquardt Algorithm ◽  
Molecular Weight Regulator ◽  
Styrene Butadiene ◽  
Original Formula

The effect of the amounts of initiator, emulsifier, and molecular weight regulator on the styrene butadiene rubber performance was investigated, based on the industrial original formula. It was found that the polymerization rate was increased with the increased dosage of initiator and emulsifier, and together with replenishing molecular weight regulator will make the Mooney viscosity of rubber meet the national standard when the conversion rate reaches 70%. The backpropagation neural network was trained by the original formula and ameliorated formula on the basis of Levenberg-Marquardt algorithm, and the relative error between the simulation results and experimental data is less than 1%. The good consistency shows that the BP neural network could predict the product performances in different formula conditions. It would pave the way for adjustment of the SBR formulation and prediction of the product performances.

Moisture content of the melt as a factor in the efficiency of orthophosphoric acid as molecular-weight regulator for polycaproamide

1977 ◽  
Vol 8 (6) ◽  
pp. 602-607
Author(s):  
L. N. Mizerovskii ◽  
V. G. Silant'eva ◽  
T. S. Usachev ◽  
Yu. S. Paikachev ◽  
N. V. Sholichev ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Moisture Content ◽  
Orthophosphoric Acid ◽  
Molecular Weight Regulator

scholarly journals Application of Molecular Weight Regulators for the Synthesis of Sodium Polyacrylate Thinners of Mineral Suspensions

2020 ◽  
Author(s):  
Dmitry Belov
Keyword(s):  
Molecular Weight ◽  
Sodium Acrylate ◽  
Sodium Polyacrylate ◽  
Molecular Weights ◽  
Ceramic Slurry ◽  
Molecular Weight Characteristics ◽  
Acrylate Polymers ◽  
Molecular Weight Regulator ◽  
Mineral Suspensions ◽  
Polymeric Samples

The synthesis of additives for thinning mineral suspensions based on sodium polyacrylate was carried out. The effect of molecular weight regulators on the molecular weight characteristics of the polymer and the effect of such polymers on the rheological properties of suspensions was studied. Sodium acrylate polymers are synthesized by free radical polymerization in aqueous solution using molecular weight regulators. The molecular weight characteristics of the polymeric samples were estimated by viscometry using Mark-Houwink-Kuhn-Sakurada (MHKS) equation. Synthesized polymers were used as thinners ceramic slurries, prepared according to the recipe of the enterprises producing ceramic products. The thinning ability of polymer samples with different molecular weights was estimated using an Engler viscometer from the time of the ceramic slurry flow. The influence of the type and amount molecular weight regulator on polyacryates was revealed. It was found that molecular weight synthesized samples was in the range of 21000 - 91000. It was determined that samples with a molecular weight of 28000 - 35000 synthesized using mercaptoethanol (at a dosage of 0.5-1.5% by weight of the monomer) provide optimal fluidity to the ceramic slurry.

scholarly journals Synthesis and Application of a Thermoplastic Plate of Poly(lactide-ε-caprolactone) for Radiation Therapy

Biomolecules ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 27
Author(s):  
Hongli Li ◽  
Wenzhi Li ◽  
Hongtao Wu ◽  
Dengbang Jiang ◽  
Mingwei Yuan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Shape Memory ◽  
Gel Permeation Chromatography ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
Clinical Effects ◽  
Recovery Rates ◽  
Single Screw Extruder ◽  
Molecular Weight Regulator ◽  
Deformation Recovery

In this study, the poly(lactide-ε-caprolactone) (P(LA-CL)) copolymer is synthesized by ring-opening polymerization with glycol used as a molecular weight regulator to adjust the molecular weight of the polymer. The proton nuclear magnetic resonance spectroscopy and gel permeation chromatography (GPC) results demonstrate that the P(LA-CL) copolymer is successfully synthesized, and that the molecular weight can be controlled by the glycol content. The thermoplastic plate is processed with triallyl isocyanurate as a cross-linking agent by a single-screw extruder followed by γ-ray irradiation. Shape memory test results show that the material had the desired shape memory effect, with deformation recovery rates reaching 100%. After secondary stretching of samples, deformation recovery rates are unchanged. The results of mechanical property measurements indicate that with added lactide, the tensile strength is improved and shore hardness is increased by 20%–30%. Data from clinical trials also reveal that the material has good clinical effects in thermoplastic membrane fixation.

Preparation and Cement Fluidity of Slow-Release Polycarboxylate-Type Superplasticizer

2011 ◽  
Vol 399-401 ◽  
pp. 1307-1311 ◽  
Author(s):  
Xia Lv ◽  
Cheng Bing Yu ◽  
Wen Ying Qi
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Polyethylene Glycol ◽  
Acrylic Acid ◽  
High Performance ◽  
Slow Release ◽  
Thioglycolic Acid ◽  
Ammonium Persulfate ◽  
Allyl Ether ◽  
Molecular Weight Regulator

High performance polycarboxylate-type superplasticizer (PCSP) was synthesized with acrylic acid (AA), polyethylene glycol allyl ether (APEG) and one monomer of methyl acrylate (MA), methacrylate acid (MAA), acrylamide (AM), and ethyleneglycol dimethacrylate (EGDMA). Ammonium persulfate and thioglycolic acid, as an initiator and a molecular weight regulator respectively, were used for radical polymerization in aqueous solution. Influence of superplasticizer on the cement fluidity of grout was investigated. The results showed that plasticizer admixture compounded with EGDMA-APEG-AA had excellent dispersibility and slump retention.

Evaluation of the dark field method for large association of spread DNA

1978 ◽  
Vol 36 (2) ◽  
pp. 190-191
Author(s):  
Douglas C. Barker
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Mitochondrial Dna ◽  
Extraction Method ◽  
Field Method ◽  
Dark Field ◽  
Kinetoplast Dna ◽  
Field Electron ◽  
Field Electron Microscopy ◽  
Dark Field Electron

A number of satisfactory methods are available for the electron microscopy of nicleic acids. These methods concentrated on fragments of nuclear, viral and mitochondrial DNA less than 50 megadaltons, on denaturation and heteroduplex mapping (Davies et al 1971) or on the interaction between proteins and DNA (Brack and Delain 1975). Less attention has been paid to the experimental criteria necessary for spreading and visualisation by dark field electron microscopy of large intact issociations of DNA. This communication will report on those criteria in relation to the ultrastructure of the (approx. 1 x 10-14g) DNA component of the kinetoplast from Trypanosomes. An extraction method has been developed to eliminate native endonucleases and nuclear contamination and to isolate the kinetoplast DNA (KDNA) as a compact network of high molecular weight. In collaboration with Dr. Ch. Brack (Basel [nstitute of Immunology), we studied the conditions necessary to prepare this KDNA Tor dark field electron microscopy using the microdrop spreading technique.

Introduction

1978 ◽  
Vol 36 (3) ◽  
pp. 543-544
Author(s):  
W. Bernard
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Nucleic Acid ◽  
Gene Mapping ◽  
Molecular Genetics ◽  
Cell Biology ◽  
Gene Activity ◽  
Close Connection ◽  
Basic Information ◽  
Simple Systems

In comparison to many other fields of ultrastructural research in Cell Biology, the successful exploration of genes and gene activity with the electron microscope in higher organisms is a late conquest. Nucleic acid molecules of Prokaryotes could be successfully visualized already since the early sixties, thanks to the Kleinschmidt spreading technique - and much basic information was obtained concerning the shape, length, molecular weight of viral, mitochondrial and chloroplast nucleic acid. Later, additonal methods revealed denaturation profiles, distinction between single and double strandedness and the use of heteroduplexes-led to gene mapping of relatively simple systems carried out in close connection with other methods of molecular genetics.

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