INVESTIGATION OF DIFFERENT CROSS-LINKING METHODS OF EOC:PDMS THERMOPLASTIC ELASTOMERS FOR CABLE INSULATION APPLICATION WITH SPECIAL REFERENCE TO THERMAL, RHEOLOGICAL, CREEP, AND ELECTRICAL PROPERTIES

2017 ◽  
Vol 90 (4) ◽  
pp. 585-610 ◽  
Author(s):  
Padmanabhan Ramachandran ◽  
Joyeeta Dutta ◽  
Tuhin Chatterjee ◽  
Golok B. Nando ◽  
Kinsuk Naskar
Keyword(s):  
Tensile Strength ◽  
Thermal Studies ◽  
Volume Resistivity ◽  
Thermoplastic Elastomers ◽  
Cross Linking ◽  
Rubber Blends ◽  
Degradation Temperature ◽  
Monomer Content ◽  
Ethylene Octene Copolymer ◽  
The Cross

ABSTRACT This article demonstrates the influence of different cross-linking methods of the ethylene octene copolymer (EOC)–polydimethylsiloxane (PDMS) rubber blends. From rheology analysis, it is understood that the EOC with a high co-monomer content has better radiation cross-linkability as compared with the EOC with a low co-monomer content. Also, from the curing study using an oscillating die rheometer, it was found that as the octene content increases, the cross-linking efficiency of the peroxide to cross-link that particular EOC decreases. The tensile strength of the EOC2:PDMS blend with a high co-monomer content was drastically improved by 39% on irradiation with a dosage of 50 kGy, whereas for the EOC:PDMS blend with a low co-monomer content, the tensile strength was drastically improved by 60% on peroxide cross-linking. It is inferred that both the peroxide and radiation cross-linked blends show higher creep resistance compared with the neat blends. From the thermal studies, it was found that through blending and subsequent radiation cross-linking, the maximum degradation temperature of the high-octene-content EOC was increased from 480.5 °C to 509.1 °C. The cross-linked blends show higher-volume resistivity as compared with the un-cross-linked counterparts.

Preparation and Application of Electrospinning Membranes of Thermoplastic Carboxymethyl Cellulose/PLA for Removal of Cu2+ from Aqueous Solutions

2012 ◽  
Vol 724 ◽  
pp. 61-64
Author(s):  
Ying Li ◽  
Xiao Yan Lin ◽  
Zhe Chen ◽  
Xue Guang Luo ◽  
Wei Li Zuo
Keyword(s):  
Tensile Strength ◽  
Aqueous Solutions ◽  
Removal Efficiency ◽  
Composite Membrane ◽  
Carboxymethyl Cellulose ◽  
Contact Time ◽  
Electrospinning Process ◽  
Cross Linking ◽  
Initial Concentration ◽  
The Cross

A composite membrane of thermoplastic carboxymethyl cellulose (TCMC) /PLA was prepared by electrospinning process, and crossliked by epichlorohydrin solution at different temperature. The cross-linking temperature was optimized by characterizing the morphology and tensile strength of the film. The optimal cross-linking temperature was 50°C. A composite membrane was used to remove Cu2+ from aqueous solutions, and the effects of initial concentration of Cu2+ and contact time on the removal efficiency of Cu2+ were investigated. The removal efficiency of Cu2+ was 13.78%, at the initial concentration of 40 mg·L-1 and contact time of 30s.

Preparation and Properties of DCP-Crosslinked Biobased Polyamide

2013 ◽  
Vol 634-638 ◽  
pp. 1037-1043 ◽  
Author(s):  
Xiao Xue ◽  
Qing Xiu Jia ◽  
Guo Liang Zhao
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Infrared Spectroscopy ◽  
Cross Linking ◽  
Dicumyl Peroxide ◽  
Elongation At Break ◽  
Gel Content ◽  
Dose Ranging ◽  
The Cross ◽  
Higher Doses

In this work, a new bio-based hybrid polyamide (BDIS) was prepared and was cross-linked by dicumyl peroxide (DCP) with dose ranging from 1 to 7%. The state of cure was observed in vulcameter, and the vulcanization condition was determined subsequently. The cross-linking efficiency of BDIS/DCP blends was assessed using torque, gel content measurements and infrared spectroscopy (FTIR). DCP dose below 1% was not sufficient to reach gelation. Over 1%, the gel content increased with increasing DCP dose. The cross-linked BDIS films exhibited enhanced toughness and mechanical properties compared to precursors. Optimal mechanical properties were obtained with concentration of about 5 wt % DCP. At higher doses, the tensile strength and the elongation at break were decreased due to scission reactions.

scholarly journals Cross-linked coacervates of cashew gum and gelatin in the encapsulation of pequi oil

2019 ◽  
Vol 49 (12) ◽  
Author(s):  
Joana de Barros Alexandre ◽  
Tiago Linhares Cruz Tabosa Barroso ◽  
Marília de Albuquerque Oliveira ◽  
Francisco Rogênio da Silva Mendes ◽  
José Maria Correia da Costa ◽  
...  
Keyword(s):  
Tannic Acid ◽  
Cross Linking ◽  
Cashew Gum ◽  
Degradation Temperature ◽  
Compound Design ◽  
Ge Matrix ◽  
The Cross ◽  
Microparticle Formation ◽  
Oppositely Charged ◽  
Oil Particles

ABSTRACT: Pequi oil is rich in bioactive compounds which can be encapsulated to increase protection against extrinsic environmental factors. A delayed degradation of pequi oil may occur by using microencapsulation technology, in addition to masking unpleasant flavors and aromas. Complex coacervation is a technique based on the electrostatic interaction between two oppositely charged biopolymers which form a matrix complexed around an agent of interest. However, cross-linking the particles is often necessary in order to make them more rigid. The objective of this research was to produce and characterize pequi oil microparticles in a cashew gum (CG) and gelatin (GE) matrix cross-linked with tannic acid. Cross-linked pequi oil microparticles were produced by varying the concentrations of biopolymers (0.5% to 1.5%) and tannic acid (0.3% to 8.1%) using a rotational central compound design. Ratio of cashew gum, gelatin and oil was 2:1:1 (m/m/m);respectively, at pH 4.5. The cross-linking process was performed with tannic acid for 30 minutes at 40 °C. The optimized formulation by means of the rotational central compound design for microparticle formation was 0.65% biopolymers (CG and GE) and 6.9% tannic acid. Increasing the tannic acid percentage in the cross-linking of the pequi oil particles had a higher yield and encapsulation efficiency. Cross-linking provided an increase in the degradation temperature of material; and consequently, improved the thermal stability of the particles. The cross-linking process was advantageous in producing the microparticles.

scholarly journals Tartaric Acid Cross-Linking of Starch: Effect of Reaction Conditions on the Maximum Tensile Strength of Cast Plastic Films

2015 ◽  
Vol 8 (3) ◽  
Author(s):  
Arturo José Mendoza
Keyword(s):  
Tensile Strength ◽  
Tartaric Acid ◽  
Low Cost ◽  
Thermoplastic Starch ◽  
Cross Linking ◽  
Reaction Conditions ◽  
Maximum Tensile Strength ◽  
Polycarboxylic Acids ◽  
The Cross ◽  
London Dispersion

Modification of starch by cross-linking is used in many fields, as the process improves many of the properties of starch, yet most cross-linking agents in common use tend to be toxic, expensive, or both. Polycarboxylic acids could function as nontoxic alternatives to these – some, such as tartaric acid (TA) being also of low cost. This study presents a method to cross-link thermoplastic starch films with TA, as well as the effect of this modification on the tensile strength of the material when films are prepared using different reaction conditions. An increase in strength was observed, which is believed to occur due to an increase in the London dispersion forces acting within the cross-linked starch (CLS). The greatest observed increase in the maximum tensile strength of the plastic was 6%. Monosodium tartrate was used as a catalyst for the cross-linking reaction. The maximum tensile strengths of the plastics produced were determined by using adapted binder clips, a hook (total mass 10g) and hanging masses to subject films of the plastics to progressively greater tension. Incremental weights of 10g were used, with recorded tensions at fracture of 1.2~8.9 N.

scholarly journals Investigation of the functional network modifier loading on the stoichiometric ratio of epoxy resins and their dielectric properties

2021 ◽  
Author(s):  
Istebreq A. Saeedi ◽  
Sunny Chaudhary ◽  
Thomas Andritsch ◽  
Alun S. Vaughan
Keyword(s):  
Glass Transition ◽  
Dielectric Properties ◽  
Electrical Properties ◽  
Epoxy Resins ◽  
Functional Network ◽  
Cross Linking ◽  
Network Modifier ◽  
Epoxy Resin System ◽  
The Cross ◽  
The Impact

AbstractReactive molecular additives have often been employed to tailor the mechanical properties of epoxy resins. In addition, several studies have reported improved electrical properties in such systems, where the network architecture and included function groups have been modified through the use of so-called functional network modifier (FNM) molecules. The study reported here set out to investigate the effect of a glycidyl polyhedral oligomeric silsesquioxane (GPOSS) FNM on the cross-linking reactions, glass transition, breakdown strength and dielectric properties of an amine-cured epoxy resin system. Since many previous studies have considered POSS to act as an inorganic filler, a key aim was to consider the impact of GPOSS addition on the stoichiometry of curing. Fourier transform infrared spectroscopy revealed significant changes in the cross-linking reactions that occur if appropriate stoichiometric compensation is not made for the additional epoxide groups present on the GPOSS. These changes, in concert with the direct effect of the GPOSS itself, influence the glass transition temperature, dielectric breakdown behaviour and dielectric response of the system. Specifically, the work shows that the inclusion of GPOSS can result in beneficial changes in electrical properties, but that these gains are easily lost if consequential changes in the matrix polymer are not appropriately counteracted. Nevertheless, if the system is appropriately optimized, materials with pronounced improvements in technologically important characteristics can be designed.

scholarly journals The Effect of Surfactant-Modified Montmorillonite on the Cross-Linking Efficiency of Polysiloxanes

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2623
Author(s):  
Monika Wójcik-Bania ◽  
Jakub Matusik
Keyword(s):  
Total Pore Volume ◽  
Cross Linking ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
The Cross ◽  
Chain Lengths ◽  
First Time ◽  
Substituent Influence ◽  
Benzyl Substituent

Polymer–clay mineral composites are an important class of materials with various applications in the industry. Despite interesting properties of polysiloxanes, such matrices were rarely used in combination with clay minerals. Thus, for the first time, a systematic study was designed to investigate the cross-linking efficiency of polysiloxane networks in the presence of 2 wt % of organo-montmorillonite. Montmorillonite (Mt) was intercalated with six quaternary ammonium salts of the cation structure [(CH3)2R’NR]+, where R = C12, C14, C16, and R’ = methyl or benzyl substituent. The intercalation efficiency was examined by X-ray diffraction, CHN elemental analysis, and Fourier transform infrared (FTIR) spectroscopy. Textural studies have shown that the application of freezing in liquid nitrogen and freeze-drying after the intercalation increases the specific surface area and the total pore volume of organo-Mt. The polymer matrix was a poly(methylhydrosiloxane) cross-linked with two linear vinylsiloxanes of different siloxane chain lengths between end functional groups. X-ray diffraction and transmission electron microscopy studies have shown that the increase in d-spacing of organo-Mt and the benzyl substituent influence the degree of nanofillers’ exfoliation in the nanocomposites. The increase in the degree of organo-Mt exfoliation reduces the efficiency of hydrosilylation reaction monitored by FTIR. This was due to physical hindrance induced by exfoliated Mt particles.

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