The Structural Studies of Oxirane Ring Opening Reaction in Epoxidized Natural Rubber (ENR-50) by SnCl2.2H2O and the Formation of ENR/TiN Complex Hybrid

2012 ◽  
Vol 626 ◽  
pp. 727-737
Author(s):  
Hamzah Rosniza ◽  
Abu Bakar Mohamad
Keyword(s):  
Natural Rubber ◽  
Ring Opening ◽  
Covalent Bond ◽  
Methine Proton ◽  
Oxirane Ring ◽  
Epoxidized Natural Rubber ◽  
H Nmr ◽  
Ring Opening Reaction ◽  
Complex Hybrid ◽  
C Nmr

Oxirane ring opening reaction of epoxidized natural rubber (ENR-50) is a promising method to produce hybrids or introduce reactive fillers into the polymers through the covalent bond. This paper reports the reaction between ENR-50 and SnCl2.2H2O under CO2environment. The complex formation is characterized via FTIR,1H,13C and119Sn NMR.1H NMR which displays deduction of methine proton integrals at δ 2.71 ppm implies the occurrence ring opening reaction. While13C NMR reveals new peaks which corresponds to Sn-C bond. The119Sn NMR proves four-coordinates tin in ENR/Sn complex hybrid.

scholarly journals Ring-opening reaction of 2,5-dioctyldithieno[2,3-b:3',2'-d]thiophene in the presence of aryllithium reagents

2013 ◽  
Vol 9 ◽  
pp. 767-774 ◽  
Author(s):  
Hao Zhong ◽  
Jianwu Shi ◽  
Jianxun Kang ◽  
Shaomin Wang ◽  
Xinming Liu ◽  
...  
Keyword(s):  
Low Temperature ◽  
Ring Opening ◽  
H Nmr ◽  
Ring Opening Reaction ◽  
Ring Opening Reactions ◽  
C Nmr

In this paper, the ring-opening reaction of 2,5-dioctyldithieno[2,3-b:3',2'-d]thiophene with aryllithium in THF at low temperature to generate 2'-arylthio-3,3'-bithiophene-2-carbaldehydes is studied. Nine examples are explored and all the products are characterized by 1H NMR, 13C NMR and HRMS. The relative relationship between the structures of aryl groups and the efficiency of ring-opening reactions are discussed.

NMR study of ring opening reaction of epoxidized natural rubber in presence of potassium hydroxide/isopropanol solution

2017 ◽  
Vol 59 ◽  
pp. 55-66 ◽  
Author(s):  
Omar S. Dahham ◽  
Rosniza Hamzah ◽  
Mohamad Abu Bakar ◽  
Nik Noriman Zulkepli ◽  
Saad S. Dahham ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Ring Opening ◽  
Potassium Hydroxide ◽  
Epoxidized Natural Rubber ◽  
Nmr Study ◽  
Ring Opening Reaction ◽  
Isopropanol Solution

Preparation of Cyclopentyl Trisilanol Silsesquioxanes - Modified Natural Rubber (CpSSQ(OH)3 ENR-50) Composite Hybrid in the Presence of HCL Acid

2013 ◽  
Vol 795 ◽  
pp. 251-255 ◽  
Author(s):  
Rosniza Hamzah ◽  
Mohamad Abu Bakar ◽  
Nik Noriman Zulkepli ◽  
Mohd Arif Anuar Mohd Salleh ◽  
Mohd Mustafa Al Bakri Abdullah
Keyword(s):  
Chemical Shift ◽  
Natural Rubber ◽  
Ring Opening ◽  
Silanol Group ◽  
Polymer Chains ◽  
Epoxide Ring ◽  
Proton Chemical Shift ◽  
Nmr Analysis ◽  
H Nmr ◽  
Ring Opening Reaction

A composite comprising cyclopentyl trisilanol silsesquioxanes (CpSSQ(OH)3) and 50% epoxidized natural rubber (ENR-50) was prepared at reflux temperature employed hydrochloric acid (HCl) as catalyst. HCl was found to be an effective catalyst to promote ring opening reaction of ENR-50 and tailored CpSSQ(OH)3to the ENR-50 polymer chains via chemical reaction. FTIR spectroscopy reveals a hydroxyl stretching indicating the occurrence of epoxide ring opening reaction.1H NMR analysis further proved the incorporation of CpSSQ(OH)3into ENR-50 polymer chains via shiftment of proton chemical shift and addition in the proton integrals. Si29NMR analysis evidence the Si-O-C bond through a chemical shift of silanol group from CpSSQ(OH)3.

Epoxidized Natural Rubber-Organomodified Montmorillonite Nanohybrids; Interaction and Thermal Decomposition

2013 ◽  
Vol 756 ◽  
pp. 119-126 ◽  
Author(s):  
Ali Salehabadi ◽  
Abu Bakar Mohamad
Keyword(s):  
Natural Rubber ◽  
Ring Opening ◽  
Decomposition Temperature ◽  
Epoxidized Natural Rubber ◽  
Solvent Casting ◽  
Casting Technique ◽  
Ring Opening Reaction ◽  
Alkyl Ammonium ◽  
Decomposition Activation Energy ◽  
Organomodified Montmorillonite

Nanohybrids, based on a modified natural rubber,Epoxidized Natural Rubber (ENR-50), and organomodified montmorillonite (MMT) containing alkyl ammonium, were prepared by solvent casting technique. Morphology and non-isothermal degradation of ENR-50 and various ENR/MMT nanohybrids were characterized by POM, SEM and TG-DTG. In the hybrid materials,an increase MMT loading in the ENR-50 increased the maximum decomposition temperature (Tmax) of thermal profiles. Kissinger and Ozawa plots deduced a trend of the decomposition activation energy, Ed, which is related to the agglomeration and heat transfer ability of MMT. A mechanism comprising of the degradation of ENR-50 via scission of epoxy-isoprene chains to shorter chains, ring opening reaction and the possible interactions of modified nanoclay and ENR-50 is discussed.

scholarly journals Expanding Monomers as Anti-Shrinkage Additives

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 806
Author(s):  
Philipp Marx ◽  
Frank Wiesbrock
Keyword(s):  
Ring Opening ◽  
Covalent Bond ◽  
Volumetric Shrinkage ◽  
Structure Property ◽  
Atomic Packing ◽  
Materials Properties ◽  
Volumetric Expansion ◽  
Structure Property Relationships ◽  
Ring Opening Reaction ◽  
Measuring Techniques

Commonly, volumetric shrinkage occurs during polymerizations due to the shortening of the equilibrium Van der Waals distance of two molecules to the length of a (significantly shorter) covalent bond. This volumetric shrinkage can have severe influence on the materials’ properties. One strategy to overcome this volumetric shrinkage is the use of expanding monomers that show volumetric expansion during polymerization reactions. Such monomers exhibit cyclic or even oligocyclic structural motifs with a correspondingly dense atomic packing. During the ring-opening reaction of such monomers, linear structures with atomic packing of lower density are formed, which results in volumetric expansion or at least reduced volumetric shrinkage. This review provides a concise overview of expanding monomers with a focus on the elucidation of structure-property relationships. Preceded by a brief introduction of measuring techniques for the quantification of volumetric changes, the most prominent classes of expanding monomers will be presented and discussed, namely cycloalkanes and cycloalkenes, oxacycles, benzoxazines, as well as thiocyclic compounds. Spiroorthoesters, spiroorthocarbonates, cyclic carbonates, and benzoxazines are particularly highlighted.

scholarly journals Optimization of the oxirane ring opening reaction in biolubricant base oil production

2016 ◽  
Vol 9 ◽  
pp. S1053-S1058 ◽  
Author(s):  
Jumat Salimon ◽  
Bashar Mudhaffar Abdullah ◽  
Nadia Salih
Keyword(s):  
Ring Opening ◽  
Oil Production ◽  
Oxirane Ring ◽  
Base Oil ◽  
Ring Opening Reaction

scholarly journals Synthesis of New Imidazolidine and Tetrahydropyrimidine Derivatives

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Hamid Beyzaei ◽  
Reza Aryan ◽  
Zahra Keshtegar
Keyword(s):  
Ring Opening ◽  
Reaction Times ◽  
Reaction Conditions ◽  
Ir Spectrometry ◽  
H Nmr ◽  
Chemical Structures ◽  
Thioamide Group ◽  
Solvent Free Conditions ◽  
Ft Ir ◽  
C Nmr

Synthesis of new imidazolidine and tetrahydropyrimidine derivatives 3a, b and 4a–c as cyclic 1,3-diamines under two reaction conditions (A and B) is described. Under reaction conditions-A, a suspension of (E)-2-cyano-2-(oxazolidin-2-ylidene)ethanethioamide 1 (1 eq.) and diaminoalkanes 2a–e (2 eq.) in absolute ethanol is heated under reflux for 16–22 h to afford 3a, b and 4a–c. Alternatively, under reaction conditions-B, a solution of thioamide 1 (1 eq.) in diaminoalkanes 2a–e (3 eq.) is stirred under solvent-free conditions at room temperature for 3 days to give desired products. Reaction conditions-A for having higher yields, shorter reaction times, and required less diamines is more effective than reaction conditions-B. Oxazolidine ring opening is observed by reacting compound 1 with all of the diamines 2a–e, but the thioamide group only reacts with nonbulky diamines 2a, b. The chemical structures of novel compounds were confirmed by 1H NMR, 13C NMR, elemental analysis, and FT-IR spectrometry.

scholarly journals An Efficient and Mild Method for the Synthesis and Hydrazinolysis ofN-Glyoxylamino Acid Esters

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Ayman El-Faham ◽  
Zainab Al Marhoon ◽  
Ahmed Abdel-Megeed ◽  
Mohamed Siddiqui
Keyword(s):  
Hydrazine Hydrate ◽  
Good Yield ◽  
Acid Ester ◽  
Ring Opening ◽  
Acid Hydrazide ◽  
Type Reaction ◽  
H Nmr ◽  
Elemental Microanalysis ◽  
Acid Esters ◽  
C Nmr

N-Glyoxylamino acid ester derivatives were synthesized via the ring opening ofN-acetylisatin using moderate conditions. During the hydrazinolysis ofN-glyoxylamino acid ester derivatives with hydrazine hydrate (80%) in methanol, unexpected reduction of theα-keto group occurred to affordN-acylamino acid hydrazide derivatives in good yield (80–90%) (Wolff-Kishner type reaction). All the synthesized compounds were characterized by1H NMR,13C NMR, and elemental microanalysis.

Synthesis and characterization of polyvinylmethylsiloxanes by cationic polymerization using a solid green catalyst

e-Polymers ◽  
2017 ◽  
Vol 17 (5) ◽  
pp. 439-448 ◽  
Author(s):  
Djamal Eddine Kherroub ◽  
Mohammed Belbachir ◽  
Saad Lamouri
Keyword(s):  
Ring Opening ◽  
Polymeric Materials ◽  
Synthesis And Characterization ◽  
Green Catalyst ◽  
Characterization Methods ◽  
H Nmr ◽  
New Strategy ◽  
Cationic Ring Opening Polymerization ◽  
C Nmr

AbstractThe present work is devoted to the synthesis and characterization of vinylsiloxane polymers produced by the use of an activated natural catalyst known as Maghnite-H+. The cationic ring opening polymerization of pentavinylpentamethylcyclopentasiloxane (V5D5) made it possible to obtain the desired polymeric materials. Through this study, we have adapted a new strategy of synthesis of a siloxane polymer with relatively high molecular mass, using a solid initiator activated by sulfuric acid, which has enabled us to combine the ecological aspect of synthesis and the effectiveness of the catalyst in this kind of reaction. Structural [infrared (IR), proton and carbon nuclear magnetic resonance (1H NMR and 13C NMR)], thermal differential scanning (DSC) and chromatographic (GPC) characterization methods have allowed the products obtained to be identified and their various properties to be focused on. The kinetic study was made to determine the order of the reaction. The proposed reaction mechanism shows the advantages of Maghnite-H+.

Sign in / Sign up

Export Citation Format

Share Document