Role of geopolymer as a cure activator in sulfur vulcanization of epoxidized natural rubber

2019 ◽  
Vol 137 (17) ◽  
pp. 48624
Author(s):  
Hassarutai Yangthong ◽  
Skulrat Pichaiyut ◽  
Suwaluk Wisunthorn ◽  
Claudia Kummerlöwe ◽  
Norbert Vennemann ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Epoxidized Natural Rubber ◽  
Sulfur Vulcanization ◽  
Cure Activator

scholarly journals Biocomposites of Epoxidized Natural Rubber/Poly(lactic acid) Modified with Natural Fillers (Part I)

2021 ◽  
Vol 22 (6) ◽  
pp. 3150
Author(s):  
Anna Masek ◽  
Stefan Cichosz ◽  
Małgorzata Piotrowska
Keyword(s):  
Tensile Strength ◽  
Lactic Acid ◽  
Natural Rubber ◽  
Epoxidized Natural Rubber ◽  
Poly Lactic Acid ◽  
Uv Aging ◽  
High Elasticity ◽  
Natural Fillers ◽  
Natural Additives

The study aimed to prepare sustainable and degradable elastic blends of epoxidized natural rubber (ENR) with poly(lactic acid) (PLA) that were reinforced with flax fiber (FF) and montmorillonite (MMT), simultaneously filling the gap in the literature regarding the PLA-containing polymer blends filled with natural additives. The performed study reveals that FF incorporation into ENR/PLA blend may cause a significant improvement in tensile strength from (10 ± 1) MPa for the reference material to (19 ± 2) MPa for the fibers-filled blend. Additionally, it was found that MMT employment in the role of the filler might contribute to ENR/PLA plasticization and considerably promote the blend elongation up to 600%. This proves the successful creation of the unique and eco-friendly PLA-containing polymer blend exhibiting high elasticity. Moreover, thanks to the performed accelerated thermo-oxidative and ultraviolet (UV) aging, it was established that MMT incorporation may delay the degradation of ENR/PLA blends under the abovementioned conditions. Additionally, mold tests revealed that plant-derived fiber addition might highly enhance the ENR/PLA blend’s biodeterioration potential enabling faster and more efficient growth of microorganisms. Therefore, materials presented in this research may become competitive and eco-friendly alternatives to commonly utilized petro-based polymeric products.

ZINC OXIDE VERSUS MAGNESIUM OXIDE REVISITED. PART 1

2012 ◽  
Vol 85 (1) ◽  
pp. 38-55 ◽  
Author(s):  
Manuel Guzmán ◽  
Berta Vega ◽  
Núria Agulló ◽  
Ulrich Giese ◽  
Salvador Borrós
Keyword(s):  
Zinc Oxide ◽  
Environmental Impact ◽  
Natural Rubber ◽  
Metal Oxides ◽  
Environmental Effects ◽  
Model Compound ◽  
Rubber Industry ◽  
Sulfur Vulcanization ◽  
Activator System

Abstract Zinc oxide is a widely used compound in the rubber industry due to the excellent properties that it shows as activator, and consequently, its role in the mechanism of accelerated sulfur vulcanization has been extensively studied. Due to the increased concern about its environmental effects, several research studies have been carried out in order to substitute it with different metal oxides such us MgO. The effect of the activator system in order to minimize the environmental impact of the rubber goods has been explored. The work developed is presented in two parts. In Part 1, the influence of different mixtures of ZnO and MgO on the vulcanization of natural rubber has been investigated. In Part 2, model compound vulcanization has been used to study the role of MgO on the mechanism to gain a better understanding of the differences shown in Part 1.

ZINC OXIDE VERSUS MAGNESIUM OXIDE REVISITED. PART 2

2012 ◽  
Vol 85 (1) ◽  
pp. 56-67 ◽  
Author(s):  
Manuel Guzmán ◽  
Berta Vega ◽  
Núria Agulló ◽  
Salvador Borrós
Keyword(s):  
Zinc Oxide ◽  
Environmental Impact ◽  
Natural Rubber ◽  
Metal Oxides ◽  
Environmental Effects ◽  
Model Compound ◽  
Rubber Industry ◽  
Sulfur Vulcanization ◽  
Activator System

Abstract Zinc oxide is a widely used compound in the rubber industry due to the excellent properties that it shows as an activator and, consequently, its role in the mechanism of accelerated sulfur vulcanization has been extensively studied. Due to the increased concern about its environmental effects, several research studies have been carried out in order to substitute it with different metal oxides such us MgO. The effect of the activator system in order to minimize the environmental impact of the rubber goods has been explored. The work developed is presented in two parts. In Part 1, the influence of different mixtures of ZnO and MgO in the vulcanization of natural rubber has been investigated. In Part 2 of the study, model compound vulcanization has been used to study the role of MgO on the mechanism to gain a better understanding of the differences shown in the first part.

CURE CHARACTERISTICS OF DEVULCANIZED RUBBER:THE ISSUE OF LOW SCORCH

2017 ◽  
Vol 90 (3) ◽  
pp. 536-549 ◽  
Author(s):  
Anu Mary Joseph ◽  
Benny George ◽  
K. N. Madhusoodanan ◽  
Rosamma Alex
Keyword(s):  
Solvent Extraction ◽  
Natural Rubber ◽  
Main Chain ◽  
Process Safety ◽  
Original Sample ◽  
Vulcanized Rubber ◽  
Sulfur Vulcanization ◽  
Natural Rubber Vulcanizates ◽  
Devulcanized Rubber

ABSTRACT We investigate the reasons behind the observed low scorch during the revulcanization of devulcanized rubber. Mechanically devulcanized carbon black filled natural rubber vulcanizates originally cured by conventional vulcanization (CV), semiefficient vulcanization (semi EV), efficient vulcanization (EV), and peroxide systems as well as buffing dust obtained from pre-cured tread with known formulation were used. Revulcanization of these devulcanized samples using sulfur/sulfonamide system led to the following observations; irrespective of the type of sulfur cure system used for the initial vulcanization of the rubber, (i) the devulcanized samples cured without pre-vulcanization induction time and (ii) devulcanized samples prepared from peroxide vulcanized rubber cured with scorch safety. Based on the earlier reports that solvent extraction of devulcanized rubber did not improve the scorch time during revulcanization, the role of zinc bound non-extractable moieties was investigated using devulcanized rubber prepared from activator-free vulcanizates, which disproved the role of such moieties. This confirmed that the scorch reducing moieties should be attached to the rubber main chain, which can be unreacted crosslink precursors and cyclic sulfides left after the initial accelerated sulfur vulcanization of the original sample. The ability of pre-vulcanization inhibitor to induce scorch safety when devulcanized rubber is revulcanized as such, without adding any virgin rubber, proved that mercaptobenzothiazole (MBT) generated from crosslink precursors is the cause of low scorch. Acetone extracted devulcanized rubber samples prepared from tetramethyl thiuramdisulfide (TMTD) cured natural rubber, which does not follow the MBT pathway when revulcanized, cured with scorch safety, which further proved the role of MBT. Based on the previous reports and our results, it is obvious that powdering of rubber vulcanizate and devulcanization processes have no role on the low process safety of these materials, but it is inherent to the initial accelerated sulfur vulcanization chemistry undergone by these materials.

Rice husk ash filled natural rubber. III. Role of metal oxides in kinetics of sulfur vulcanization

2003 ◽  
Vol 90 (6) ◽  
pp. 1519-1531 ◽  
Author(s):  
H. M. da Costa ◽  
L. L. Y. Visconte ◽  
R. C. R. Nunes ◽  
C. R. G. Furtado
Keyword(s):  
Natural Rubber ◽  
Metal Oxides ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Sulfur Vulcanization ◽  
Kinetics Of

Activators in Accelerated Sulfur Vulcanization

2004 ◽  
Vol 77 (3) ◽  
pp. 512-541 ◽  
Author(s):  
Geert Heideman ◽  
Rabin N. Datta ◽  
Jacques W. M. Noordermeer ◽  
Ben van Baarle
Keyword(s):  
Reaction Mechanisms ◽  
Model Compound ◽  
Background Information ◽  
Zinc Compounds ◽  
Chemical Mechanisms ◽  
Sulfur Vulcanization ◽  
Multifunctional Additives ◽  
Vulcanization Process

Abstract This review provides relevant background information about the vulcanization process, as well as the chemistry of thiuram- and sulfenamide-accelerated sulfur vulcanization with emphasis on the role of activators, to lay a base for further research. It commences with an introduction of sulfur vulcanization and a summary of the reaction mechanisms as described in literature, followed by the role of activators, particularly ZnO. The various possibilities to reduce ZnO levels in rubber compounding, that have been proposed in literature, are reviewed. A totally different approach to reduce ZnO is described in the paragraphs about the various possible roles of multifunctional additives (MFA) in rubber vulcanization. Another paragraph is dedicated to the role of amines in rubber vulcanization, in order to provide some insight in the underlying chemical mechanisms of MFA systems. Furthermore, an overview of Model Compound Vulcanization (MCV) with respect to different models and activator/accelerator systems is given. In the last part of this review, the various functions of ZnO in rubber are summarized. It clearly reveals that the role of ZnO and zinc compounds is very complex and still deserves further clarification.

Preparation coated of urea beads from banana peel bioplastic and epoxidized natural rubber 50

2020 ◽  
Author(s):  
H. K. Abdulkadir ◽  
S. A. Abdul Shukor ◽  
R. Hamzah ◽  
N. Z. Noriman ◽  
Omar S. Dahham ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Epoxidized Natural Rubber ◽  
Banana Peel
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