Resins Used in Rubber

1963 ◽  
Vol 36 (5) ◽  
pp. 1542-1570 ◽  
Author(s):  
Paul O. Powers
Keyword(s):  
Molecular Weight ◽  
Organic Substances ◽  
Thermosetting Resins ◽  
Average Value ◽  
Synthetic Rubber ◽  
Naturally Occurring ◽  
Synthetic Resins ◽  
Natural And Synthetic

Abstract Resinous materials have long been used to aid in the processing of rubber and to impart special properties to the vulcanized product. Resins have been described as various solid or semisolid organic substances. Originally, naturally occurring resins such as rosin were employed but with the advent of synthetic resins, many of these have been used with natural and synthetic rubber. In general the resins considered here are readily fusible and relatively low in molecular weight, the average value often being less than one thousand. However, thermosetting resins are also employed, usually being introduced into the rubber at a low stage of condensation. Resins are frequently added to assist in processing and often are considered as softeners although they are higher in molecular weight than most softeners and their efficiency as softeners is somewhat less. However, they do not soften the resulting vulcanizate and may even increase the hardness.

Natural and Synthetic Rubber. II. Reduction of Isoprene by Na-Nh3

1929 ◽  
Vol 2 (3) ◽  
pp. 452-452
Author(s):  
Thomas Midgley ◽  
Albert L. Henne
Keyword(s):  
Molecular Weight ◽  
Double Bond ◽  
Low Temperature ◽  
High Molecular Weight ◽  
Liquid Ammonia ◽  
Volatile Hydrocarbon ◽  
Hydrogen Addition ◽  
Synthetic Rubber ◽  
Reaction Proceeds ◽  
Natural And Synthetic

Abstract The reduction of isoprene by sodium in liquid ammonia was attempted to determine: (1) whether reduction would take place in preference to polymerization and (2) the location of the added hydrogen. Isoprene was added to sodium dissolved in liquid ammonia and a 60% yield of 2-methyl-2-butene resulted. No other volatile hydrocarbon was found. High molecular weight hydrocarbons were formed but were not investigated. It is thus shown: (1) that the predominant reaction proceeds in accordance with the equation C5C8+2Na+2NH3=C5C10+2NaNH2 and (2) that hydrogen adds to isoprene in the 1,4-position, in agreement with Thiele's theory. The hydrogen addition is similar to the bromination of isoprene at low temperature. If properly conducted the latter reaction stops after 2 atoms of bromine have been added to 1 molecule of isoprene; the resulting compound, 1,4-dibromo-2-methyl-2-butene, is characterized b the inactivity of its double bond toward bromine. Similarly, 2-methyl-2-butene obtained by reduction of isoprene is not reduced to isopentane by an excess of Na—NH3 reagent.

Natural and Synthetic Rubber. XIII. The Molecular Weight of Sol Rubber

1934 ◽  
Vol 56 (6) ◽  
pp. 1325-1326 ◽  
Author(s):  
Thomas Midgley ◽  
Albert L. Henne ◽  
Alvin F. Shepard ◽  
Mary W. Renoll
Keyword(s):  
Molecular Weight ◽  
Synthetic Rubber ◽  
Natural And Synthetic

Natural and Synthetic Rubber. XIII. The Molecular Weight of Sol Rubber

1934 ◽  
Vol 7 (3) ◽  
pp. 518-520
Author(s):  
Thomas Midgley ◽  
Albert L. Henne ◽  
Alvin F. Shepard ◽  
Mary W. Renoll
Keyword(s):  
Molecular Weight ◽  
Vulcanized Rubber ◽  
Synthetic Rubber ◽  
Natural And Synthetic

Abstract Partially vulcanized rubber has been fractionated into components in which rubber is combined with increasing amounts of sulfur. The analyses of these fractions concur to indicate a molecular weight of about 54,000 for the particular sample of rubber used. Specimens of varied origin can thus have their molecular weight measured by strictly orthodox chemical means.

Vulcanization of Rubber with Synthetic Resins

1946 ◽  
Vol 19 (1) ◽  
pp. 86-99 ◽  
Author(s):  
A. J. Wildschut
Keyword(s):  
Tensile Strength ◽  
Magnesium Oxide ◽  
Sulfur Compounds ◽  
Chemical Bonds ◽  
Synthetic Resin ◽  
Gutta Percha ◽  
Synthetic Rubber ◽  
Synthetic Resins ◽  
Technical Properties ◽  
Natural And Synthetic

Abstract Natural and synthetic rubber can be vulcanized with several vulcanizing agents other than sulfur, though sulfur and sulfur compounds are the only agents of practical value. A combination of rubber and synthetic resin can be successful only when chemical bonds are formed. It has been found that this is the case with certain synthetic resins, and that natural and synthetic rubber can be vulcanized with these resins, without adding any other agent or filler, in much the same way as with sulfur. An example of these resins is the resol from pentaphene (p-t-amylphenol) and formaldehyde. Data are given for the technical properties of rubber-resin vulcanizates. Catalysis or a similar effect is produced by magnesium oxide, which increases the tensile strength, while hexamethylenetetramine prevents the reaction. Balata can be vulcanized with the same synthetic resins as rubber; with gutta-percha the effect of heating with rubber-vulcanizing resins is the same as with sulfur. The probable configuration of the rubber-resin vulcanizates consists of two systems of entangled thread-molecules, which are interlinked at a limited number of points by primary valence bonds.

Naturally Occurring IgG Autoantibodies to Platelet Cytoskeleton Tropomyosin

1996 ◽  
Vol 75 (04) ◽  
pp. 642-647 ◽  
Author(s):  
Ming Hou ◽  
Dick Stockelberg ◽  
Jack Kutti ◽  
Hans Wadenvik
Keyword(s):  
Molecular Weight ◽  
Human Platelet ◽  
Chronic Idiopathic Thrombocytopenic Purpura ◽  
Thrombocytopenic Purpura ◽  
Immunoblot Assay ◽  
Specific Antibodies ◽  
Platelet Protein ◽  
Naturally Occurring ◽  
Normal Individuals ◽  
Cytoskeleton Protein

SummaryWe have observed that naturally occurring serum antibodies generated a 30 Kd band in a platelet immunoblot assay. The target protein had the same molecular weight (30 Kd) under nonreduced and reduced electrophoretic conditions, and could be immunoblotted from either autologous or homologous platelet lysates. Also, the 30 Kd reactive autoantibodies could be totally adsorbed by platelet cytoskeletons. From these data one likely candidate for the autoantibody target was the intracellular platelet protein tropomyosin. Indeed, a commercially available monoclonal antitropomyosin antibody reacted with proteins comigrating with this 30 Kd band; affinity purified human platelet tropomyosin was bound by the antibodies that recognized the 30 Kd protein. This body of evidence conclusively demonstrated that naturally occurring serum autoantibodies reacted with the platelet cytoskeleton protein - tropomyosin. These tropomyosin specific antibodies were found in roughly the same percentage of sera from patients with chronic idiopathic thrombocytopenic purpura (ITP) as from normal individuals.

Characteristics of fouling due to clay-organic substances in potable water treatment by ultrafiltration

1996 ◽  
Vol 34 (9) ◽  
pp. 157-164 ◽  
Author(s):  
Kim C.-H. ◽  
M. Hosomi ◽  
A. Murakami ◽  
M. Okada
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Humic Acid ◽  
Fulvic Acid ◽  
Size Distribution ◽  
Ultrafiltration Membrane ◽  
Organic Substances ◽  
Decomposition Products ◽  
Microbial Decomposition ◽  
Fouling Materials

Effects of clay on fouling due to organic substances and clay were evaluated by model fouling materials and kaolin. Model fouling materials selected were protein, polysaccharide, fulvic acid, humic acid and algogenic matter (EOM:ectracellular organic matter, microbial decomposition products) and kaolin was selected as the clay material. Polysulfone membrane (MWCO(Molecular Weight Cut-Off) 10,000, 50,000 and 200,000) was used as an ultrafiltration membrane. In particular, the flux measurement of solutions containing algogenic matter used an ultrafiltration membrane of MWCO 50,000. The flux of protein and polysaccharide with coexistence of kaolin increased in the case of the ratio of MW/MWCO being greater than one, but did not increase in the case of the MW/MWCO ratio being below one. In contrast, the flux of fulvic acid and humic acid with coextence of kaolin decreased regardless of the ratio of MW/MWCO. The addition of dispersion agent and coagulant in the organic substances and kaolin mixture solution changed the size distribution of kaolin, and resulted in a change of the flux. EOM and microbial decomposition products decreased with the increase of the fraction of organic matter having molecular weight more than MWCO of membrane. The flux of the algogenic organic matter with coexistence of kaolin decreased with the increase of the amount of kaolin. It was suggested that the decline of the flux with coexistence of kaolin was due to the change of the resistance of the kaolin cake layer corresponding to the change in kaolin size distribution with charge.

Coactivation of Delayed-Action Vulcanization. Part I. Polymeric, Nonmigratory Cure Coactivators for Accelerated Sulfur Vulcanization

1989 ◽  
Vol 62 (5) ◽  
pp. 957-972
Author(s):  
A. Y. Coran ◽  
F. Ignatz-Hoover ◽  
L. H. Davis
Keyword(s):  
Molecular Weight ◽  
Minimum Loss ◽  
Synthetic Rubber ◽  
Curing Characteristics ◽  
Sulfur Vulcanization ◽  
Delayed Action ◽  
Very High ◽  
Rubber Article

Abstract Rubbery vinylpyridine-butadiene copolymers, containing 20–65% by weight of vinylpyridine monomer units, are effective coactivators of vulcanization for TBBS-accelerated sulfur-vulcanized SBR. In addition to emulsion SBR, the new co-activator has been evaluated in copositions of solution SBR, BR, NR, and various blends. The co-activator is active in all of the compositions which contain butadiene-derived synthetic rubber. This includes blends such as SBR/BR, solution-SBR/BR, SBR/NR, BR/NR, SBR/BR/NR, etc. There is little or no activity in which NR is the only polymer. The most efficacious copolymers contain between 30 and 60% 2-vinylpyridine. The incorporation of such a copolymer into an unvulcanized butadiene-derived rubber mix can give a substantial increase in the rate of crosslink formation with only a minimum loss of scorch resistance. Since the polymeric coactivators are very high in molecular weight, it can be at least tentatively concluded that they will not migrate from one component stock to another in a built-up multi-stock rubber article, either before or during vulcanization. Since the curing characteristics of a vinylpyridine-copolymer-containing TBBS-accelerated stock can be similar to those of TBBS-accelerated NR, it might be concluded that the new additives will solve some of the problems in balancing the cures of adjacent NR and SBR stocks in a multicomponent cured rubber article.

scholarly journals Alternative of bone china and porcelain as ceramic hand molds for rubber latex glove films formation via dipping process

2020 ◽  
Vol 59 (1) ◽  
pp. 523-537
Author(s):  
Chaturaphat Tharasana ◽  
Aniruj Wongaunjai ◽  
Puwitoo Sornsanee ◽  
Vichasharn Jitprarop ◽  
Nuchnapa Tangboriboon
Keyword(s):  
Thermal Expansion ◽  
Flexural Strength ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Mold Surface ◽  
Rubber Latex ◽  
Latex Glove ◽  
Bone China ◽  
Synthetic Rubber ◽  
Natural And Synthetic

AbstractIn general, the main compositions of porcelain and bone china composed of 54-65%wt silica (SiO2), 23-34% wt alumina (Al2O3) and 0.2-0.7%wt calcium oxide (CaO) suitable for preparation high quality ceramic products such as soft-hard porcelain products for teeth and bones, bioceramics, IC substrate and magneto-optoelectroceramics. The quality of ceramic hand mold is depended on raw material and its properties (pH, ionic strength, solid-liquid surface tension, particle size distribution, specific surface area, porosity, density, microstructure, weight ratio between solid and water, drying time, and firing temperatures). The suitable firing conditions for porcelain and bone china hand-mold preparation were firing at 1270°C for 10 h which resulted in superior working molds for making latex films from natural and synthetic rubber. The obtained fired porcelain hand molds at 1270°C for 10 h provided good chemical durability (10%NaOH, 5%HCl and 10%wtNaCl), low thermal expansion coefficient (5.8570 × 10−6 (°C−1)), good compressive (179.40 MPa) and good flexural strength (86 MPa). While thermal expansion coefficient, compressive and flexural strength of obtained fired bone china hand molds are equal to 6.9230 × 10−6 (°C−1), 128.40 and 73.70 MPa, respectively, good acid-base-salt resistance, a smooth mold surface, and easy hand mold fabrication. Both obtained porcelain and bone china hand molds are a low production cost, making them suitable for natural and synthetic rubber latex glove formation.

Sign in / Sign up

Export Citation Format

Share Document