Synthesis of biobased epoxy and curing agents using rosin and the study of cure reactions

Abstract In general HC-434 is a relatively homogeneous, difunctional polymer that can be readily chain extended through a variety of cure reactions. To date most of the work has been done with epoxide and aziridinyl curing agents, and a moderate amount of work has been done to improve the rates of cure by means of catalysts. Both aromatic amines and chromium salt complexes have proven to be effective catalysts. The physical properties of the chain-extended polymer with reinforcing fillers approach those of SBR vulcanizates, but improvement is still needed to achieve the properties required for tire formulations. The liquid polymer systems are suitable for belting, hose, and molding applications. However, additional work is required to develop the optimum cure systems for physical properties, faster catalysts, and alternative chain-extension reactions with other reactive curing agents.

Download Full-text

Extraction and identification of fillers and pigments from pyrolyzed rubber and tire samples

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100163332 ◽

1996 ◽

Vol 54 ◽

pp. 174-175

Author(s):

P. Sadhukhan ◽

J. B. Zimmerman

Keyword(s):

Zinc Oxide ◽

Electron Microscope ◽

Carbon Black ◽

Natural Rubber ◽

Transmission Electron Microscope ◽

Rolling Resistance ◽

Synthetic Polymers ◽

Nitrogen Atmosphere ◽

Transmission Electron ◽

Curing Agents

Rubber stocks, specially tires, are composed of natural rubber and synthetic polymers and also of several compounding ingredients, such as carbon black, silica, zinc oxide etc. These are generally mixed and vulcanized with additional curing agents, mainly organic in nature, to achieve certain “designing properties” including wear, traction, rolling resistance and handling of tires. Considerable importance is, therefore, attached both by the manufacturers and their competitors to be able to extract, identify and characterize various types of fillers and pigments. Several analytical procedures have been in use to extract, preferentially, these fillers and pigments and subsequently identify and characterize them under a transmission electron microscope.Rubber stocks and tire sections are subjected to heat under nitrogen atmosphere to 550°C for one hour and then cooled under nitrogen to remove polymers, leaving behind carbon black, silica and zinc oxide and 650°C to eliminate carbon blacks, leaving only silica and zinc oxide.

Download Full-text

Effect of Curing Agents on Electrical Properties of Low-Temperature Curing Conductive Coatings and Thermodynamic Analysis

Coatings ◽

10.3390/coatings11060656 ◽

2021 ◽

Vol 11 (6) ◽

pp. 656

Author(s):

Junjie Shu ◽

Yang Wang ◽

Bei Guo ◽

Weihua Qin ◽

Lanxuan Liu ◽

...

Keyword(s):

Electrical Properties ◽

Low Temperature ◽

Surface Resistance ◽

Advanced Manufacturing ◽

Curing Time ◽

Conductive Coatings ◽

Exponential Factor ◽

Design Expert ◽

Surface Method ◽

Curing Agents

Silver-based high-conductivity coatings are used in many advanced manufacturing equipment and components, and existing coatings require high-temperature curing. This paper studies the effects of different curing agents on the electrical properties of low-temperature curing (<100 °C) conductive coatings, and analyzes the effects of different curing temperatures and curing time on the surface resistance, square resistance and resistivity of conductive coatings. The response surface method in Design Expert was used to construct the model, and the curing thermodynamics of different curing agents were analyzed by DSC. It was found that curing agents with lower Tm and activation energy, higher pre-exponential factor and more flexible segments are beneficial to the preparation of highly conductive coatings.

Download Full-text