The Curing Reaction Rate of the Rocket Motor Liner Based on the Aging of a Curing System

The curing process of polyurethanes was investigated with FTIR method. The curves of conversion (α)VS curing reaction time (t) at different temperatures were obtained .The curing reaction of the system was found to be second order reaction. The reaction rate constants and activation energy had been measured. Effect of the use lever of curing agent and temperatures on curing reaction was discussed. The results showed that when the mole ratio of NCO/OH is smaller than 1, the crosslinking reaction take place at high temperature.

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The transition nanoreactor-nanoparticle in epoxy polymers curing process

Chemistry & Chemical Technology ◽

10.23939/chcht02.04.281 ◽

2008 ◽

Vol 2 (4) ◽

pp. 281-284

Author(s):

Georgiy Kozlov ◽

◽

Musa Bashorov ◽

Abdulakh Mikitaev ◽

Gennady Zaikov ◽

...

Keyword(s):

Molecular Weight ◽

Euclidean Space ◽

Reaction Rate ◽

Typical Feature ◽

Reaction Rate Constant ◽

Conversion Degree ◽

Curing Process ◽

Epoxy Polymers ◽

Curing Reaction ◽

Fractal Space

It has been shown that for curing reaction in fractal space the reaction rate constant reduction is typical. Another typical feature of this reaction is the formation of a large number of microgels with smaller molecular weight in comparison with reaction in Euclidean space at the same conversion degree. The dimensional border between nanoreactor and nanoparticle for the curing reaction under consideration has been obtained.

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Study on the Curing Characteristics of MUF Co-Polymerization Resin

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.183-185.2124 ◽

2011 ◽

Vol 183-185 ◽

pp. 2124-2128

Author(s):

Yun Wu Zheng ◽

Li Bin Zhu ◽

Ji You Gu ◽

Zhi Feng Zheng ◽

Yuan Bo Huang

Keyword(s):

Activation Energy ◽

Reaction Rate ◽

Reaction Order ◽

Curing Temperature ◽

Curing Agent ◽

Curing Time ◽

Curing Reaction ◽

Curing Characteristics ◽

Production Practice ◽

Run Up

Curing is the key to the bonding, this paper considered the production practice, studied the curing properties of different MUF resin under the different curing agent with DSC. The experimental results show that: The characteristics temperature of curing reaction is closely related to the β. With the increase of β, the initial and peak temperature is moving to the high-temperature, the curing time became shorter; the range of curing temperature became much wider. At the same time, the curing peaking temperature was decreased and the Enthalpy integral of curing reaction was reduced first then increased with the increased of the amount of curing agent. When the amount of curing agent occupied 4.0%-6.0% of the MUF resin, the pH was decreased mostly, and the curing reaction rate run up quickly Along with the increasing of n (F): n (U1), the To, Tp and Ti are going ahead distinctly after hardening. At the same time, both activation energy and reaction order are all decreased, absorbed heat is dropping too. So, curing technics became easily.

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Thermal Stabilities and Mechanical Interfacial Properties of Polyethresulfone-Modified Epoxy Resin

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.111.159 ◽

2006 ◽

Vol 111 ◽

pp. 159-162 ◽

Cited By ~ 2

Author(s):

Soo Jin Park ◽

K. Li ◽

S.K. Hong

Keyword(s):

Bisphenol A ◽

Epoxy Resin ◽

Reaction Rate ◽

Interfacial Properties ◽

Diglycidyl Ether ◽

Thermal Stabilities ◽

Curing Reaction ◽

Modified Epoxy

The thermal stabilities and mechanical interfacial properties of a diglycidyl ether of bisphenol-A (DGEBA) epoxy resin modified with different contents of polyethersulfone (PES) have been investigated. As a result, the curing reaction rate of DGEBA/PES blends was decreased with increasing the PES content. The blends exhibited slight decrease of thermal stabilities compared to the neat DGEBA. The mechanical interfacial properties, characterized by KIC, were significantly increased as the PES content increased.

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Locating Al in the DABCO catalyst before and after Al extraction

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100174461 ◽

1990 ◽

Vol 48 (4) ◽

pp. 265-267

Author(s):

Kathleen B. Reuter

Keyword(s):

Active Site ◽

Inverse Relationship ◽

Transverse Direction ◽

Reaction Rate ◽

Acid Phosphate ◽

Fracture Surfaces ◽

Al Content ◽

Before And After ◽

Relationship Of

The reaction rate and efficiency of piperazine to 1,4-diazabicyclo-octane (DABCO) depends on the Si/Al ratio of the MFI topology catalysts. The Al was shown to be the active site, however, in the Si/Al range of 30-200 the reaction rate increases as the Si/Al ratio increases. The objective of this work was to determine the location and concentration of Al to explain this inverse relationship of Al content with reaction rate.Two silicalite catalysts in the form of 1/16 inch SiO2/Al2O3 bonded extrudates were examined: catalyst A with a Si/Al of 83; and catalyst B, the acid/phosphate Al extracted form of catalyst A, with a Si/Al of 175. Five extrudates from each catalyst were fractured in the transverse direction and particles were obtained from the fracture surfaces near the center of the extrudate diameter. Particles were also obtained from the outside surfaces of five extrudates.

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Direct observation of Fe-Al-Zn ternary intermetallic compound and its transformation during the early stage of hot-dip galvanizing

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100151416 ◽

1993 ◽

Vol 51 ◽

pp. 1116-1117

Author(s):

C. S. Lin ◽

W. A. Chiou ◽

M. Meshii

Keyword(s):

Intermetallic Compound ◽

Reaction Rate ◽

Diffusion Rate ◽

Early Stage ◽

Zinc Bath ◽

Steel Sheets ◽

Direct Observations ◽

Solid Iron ◽

Iron And Zinc ◽

Ternary Intermetallic Compound

The galvannealed steel sheets have received ever increased attention because of their excellent post-painting corrosion resistance and good weldability. However, its powdering and flaking tendency during press forming processes strongly impairs its performance. In order to optimize the properties of galvanneal coatings, it is critical to control the reaction rate between solid iron and molten zinc.In commercial galvannealing line, aluminum is added to zinc bath to retard the diffusion rate between iron and zinc by the formation of a thin layer of Al intermetallic compound on the surface of steel at initial hot-dip galvanizing. However, the form of this compound and its transformation are still speculated. In this paper, we report the direct observations of this compound and its transformation.The specimens were prepared in a hot-dip simulator in which the steel was galvanized in the zinc bath containing 0.14 wt% of Al at a temperature of 480 °C for 5 seconds and was quenched by liquid nitrogen.

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Understanding the risks and rewards of using 50% vs. 10% strength peroxide in pulp bleach plants

TAPPI Journal ◽

10.32964/tj17.11.601 ◽

2018 ◽

Vol 17 (11) ◽

pp. 601-607

Author(s):

Alan Rudie ◽

Peter Hart

Keyword(s):

Hydrogen Peroxide ◽

Reaction Rate ◽

The Other ◽

Mechanical Pulp ◽

Engineering Controls ◽

Point Of Use ◽

Process Failure

The use of 50% concentration and 10% concentration hydrogen peroxide were evaluated for chemical and mechanical pulp bleach plants at storage and at point of use. Several dangerous occurrences have been documented when the supply of 50% peroxide going into the pulping process was not stopped during a process failure. Startup conditions and leaking block valves during maintenance outages have also contributed to explosions. Although hazardous events have occurred, 50% peroxide can be stored safely with proper precautions and engineering controls. For point of use in a chemical bleach plant, it is recommended to dilute the peroxide to 10% prior to application, because risk does not outweigh the benefit. For point of use in a mechanical bleach plant, it is recommended to use 50% peroxide going into a bleach liquor mixing system that includes the other chemicals used to maintain the brightening reaction rate. When 50% peroxide is used, it is critical that proper engineering controls are used to mitigate any risks.

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