Compounding Bromobutyl for Heat Resistance

1979 ◽  
Vol 52 (2) ◽  
pp. 319-330 ◽  
Author(s):  
J. Timar ◽  
W. S. Edwards
Keyword(s):  
Zinc Oxide ◽  
Heat Resistance ◽  
Magnesium Oxide ◽  
Heat Resistant ◽  
Active Magnesium Oxide

Abstract Bromobutyl rubber is a good candidate for heat resistant applications, particularly when cured with zinc oxide in conjunction with sulphur donors or with dithiocarbamates plus active magnesium oxide. Several antioxidants provide added protection. When suitably compounded, bromobutyl compares well with resin-cured regular butyl in heat resistance and is much faster curing.

Applications of ZnO and MgO Nanoparticles in Reducing Zinc Pollution Level in Rubber Manufacturing Processes: A Review

2020 ◽  
Vol 6 (2) ◽  
pp. 103-107 ◽  
Author(s):  
Seyyed Mohammad Javadi
Keyword(s):  
Zinc Oxide ◽  
Fatty Acid ◽  
Magnesium Oxide ◽  
Environmental Effects ◽  
Pollution Level ◽  
Oxide Nanoparticles ◽  
Mgo Nanoparticles ◽  
Magnesium Oxide Nanoparticles ◽  
Council Directive ◽  
Zno Particles

Background: Rubber vulcanization is a consolidated chemical process to enhance the mechanical properties of the polymeric material by sulfur crosslinking of the polymer chains, such as rubber. Vulcanization Activators are important rubber processing additives that activate sulfur cure and improve the efficiency of sulfur-based cure systems. The most common activator is zinc fatty acid ester that is often formed in-situ by the reaction of fatty acid with zinc oxide. Although zinc is one of the less harmful heavy metals, according to European Council Directive 2004/73/EC, the reduction of zinc level in the environment has become an important task because of its toxic effect on aquatic organisms. : The current study reviews the research achievements in the field of reducing the consumption of micronutrients of ZnO particles based on the use of nanoparticles instead of them in the polymer industry. Among the proposed methods, due to the less environmental effects of magnesium oxide, the use of MgO nanoparticles instead of zinc oxide has also achieved good results. Objective: The aim of this paper is considering suggested different methods on the reduction of using ZnO particles in related industries, the use of ZnO nanoparticles has had better results than its particles. In addition, due to the less environmental effects of magnesium oxide, magnesium oxide nanoparticles can be used instead of micronutrients of zinc oxide. Overall, the results of various investigations show that reducing the diameter of the zinc oxide particles reduces the amount required for curing the rubber and thus reduces its toxic effects. Also, the use of magnesium oxide nanoparticles instead of zinc oxide in different concentrations is investigated.

scholarly journals Molecular Physiological Characterization of a High Heat Resistant Spore Forming Bacillus subtilis Food Isolate

2021 ◽  
Vol 9 (3) ◽  
pp. 667
Author(s):  
Zhiwei Tu ◽  
Peter Setlow ◽  
Stanley Brul ◽  
Gertjan Kramer
Keyword(s):  
Bacillus Subtilis ◽  
Heat Resistance ◽  
Dipicolinic Acid ◽  
Laboratory Strain ◽  
High Heat ◽  
High Heat Resistance ◽  
Vegetative Cells ◽  
Heat Resistant ◽  
Food Isolate ◽  
Wet Heat

Bacterial endospores (spores) are among the most resistant living forms on earth. Spores of Bacillus subtilis A163 show extremely high resistance to wet heat compared to spores of laboratory strains. In this study, we found that spores of B. subtilis A163 were indeed very wet heat resistant and released dipicolinic acid (DPA) very slowly during heat treatment. We also determined the proteome of vegetative cells and spores of B. subtilis A163 and the differences in these proteomes from those of the laboratory strain PY79, spores of which are much less heat resistant. This proteomic characterization identified 2011 proteins in spores and 1901 proteins in vegetative cells of B. subtilis A163. Surprisingly, spore morphogenic protein SpoVM had no homologs in B. subtilis A163. Comparing protein expression between these two strains uncovered 108 proteins that were differentially present in spores and 93 proteins differentially present in cells. In addition, five of the seven proteins on an operon in strain A163, which is thought to be primarily responsible for this strain’s spores high heat resistance, were also identified. These findings reveal proteomic differences of the two strains exhibiting different resistance to heat and form a basis for further mechanistic analysis of the high heat resistance of B. subtilis A163 spores.

Effect of magnesium oxide passivation on the performance of amorphous indium–gallium–zinc-oxide thin film transistors

2012 ◽  
Vol 520 (10) ◽  
pp. 3783-3786 ◽  
Author(s):  
Dong Youn Yoo ◽  
Eugene Chong ◽  
Do Hyung Kim ◽  
Byeong Kwon Ju ◽  
Sang Yeol Lee
Keyword(s):  
Thin Film ◽  
Zinc Oxide ◽  
Magnesium Oxide ◽  
Thin Film Transistors ◽  
Oxide Thin Film ◽  
Indium Gallium Zinc Oxide ◽  
Zinc Oxide Thin Film ◽  
Indium Gallium

SiO2 films as heat resistant layers for protection of expandable polystyrene foam from flame torch–induced heat

2017 ◽  
Vol 31 (5) ◽  
pp. 657-667 ◽  
Author(s):  
S Varnagiris ◽  
S Tuckute ◽  
M Lelis ◽  
D Milcius
Keyword(s):  
Heat Resistance ◽  
Photoelectron Spectroscopy ◽  
Silicon Oxide ◽  
Plasma Generator ◽  
Expanded Polystyrene ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Heat Resistant ◽  
Pulsed Dc ◽  
Gas Atmosphere

Currently, polymeric insulation materials are widely used for energy saving in buildings. Despite of all benefits, these materials are generally sensitive to heat and highly flammable. This work discusses possibility to improve heat resistance of expanded polystyrene (EPS) foam using thin silicon dioxide (SiO2) films deposited by magnetron sputtering technique. In order to increase surface energy and adherence of SiO2 thin films to substrate EPS was plasma pretreated before films’ depositions using pulsed DC plasma generator for 40 s in argon gas. SiO2 formation was done in reactive argon and oxygen gas atmosphere. Laboratory made equipment was used for flame torch–induced heat resistance experiments. Results showed that silicon oxide films remains stable during heat resistance experiments up to 5 s and fully protects polystyrene (PS) substrate. Films are relatively stable for 30 s and 60 s and partially protect PS from melting and ignition. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy analysis confirmed that SiO2 layer, which is distributed uniformly on the EPS surface, could work as a good heat resistant material.

Preparation of Epoxide Rubber Containing Allylic Chloride

1969 ◽  
Vol 42 (4) ◽  
pp. 1028-1033 ◽  
Author(s):  
A. E. Gurgiolo
Keyword(s):  
Zinc Oxide ◽  
Magnesium Oxide ◽  
Propylene Oxide ◽  
Indirect Proof ◽  
Zinc Oxides ◽  
Allylic Chloride

Abstract New epoxide monomers have been prepared that contain allylic chlorine. These have been copolymerized with propylene oxide to give polymers that also contain allylic chlorine. This type of propylene oxide rubber can be vulcanized with a mixture of magnesium oxide and zinc oxide eliminating the need for sulfur in the vulcanization recipe. This work presents an indirect proof of the allylic structure of neoprene and substantiates the theory of vulcanization of neoprene by magnesium and zinc oxides.

Efficient and Semiefficient Vulcanization Systems Employing 2-(Morpholinodithio)-Benzothiazole Generated in Situ

1977 ◽  
Vol 50 (1) ◽  
pp. 90-98
Author(s):  
J. P. Lawrence
Keyword(s):  
Heat Resistance ◽  
Experimental System ◽  
Heat Resistant ◽  
Molar Basis ◽  
Direct Replacement ◽  
Better Than

Abstract The MBTS-N-(morpholinothio)phthalimide vulcanization system has been found to be effective in producing heat resistant semi-EV and EV cures in a variety of representative rubbers. When used as a direct replacement on a molar basis for 2-(morpholinodithio)benzothiazole (MDB), improvements in processing safety were found in all cases studied. In this respect it is most effective in NR, SBR, and NBR. The experimental system also generally gave slower-curing stocks. The heat resistance of the experimental stocks was found to be equal to or better than that of the MDB control stocks. Substantial improvements in heat resistance for both SBR and IIR unexpectedly resulted from the use of the MBTS—imide system. This result suggests that the nature of the crosslinks formed by the two vulcanization systems are to some extent different in these two elastomers. This, in turn, may reflect upon the mechanisms of crosslink formation.

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