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The purpose of this paper is to synthesise new fatty dicarboxylic acid half ester (NFAHE) C25, which can be used as substitute to dimer/trimer acids commonly used (C36, 54) as basic raw materials for manufacture of polyamides for printing inks or as curing agents for epoxy paints and adhesives. This could be an economically viable synthesis by which the user could manufacture the finished products from relatively low cost raw materials.

Vegetable oils have several double bonds that undergo large number of reactions. Diels‐Alder addition is one of them. Dimer acids have been produced by using these double bonds by reaction of two fatty acid molecules. Maleic acid, acrylic acid has also been used for this purpose. Sorbic acid is a derivative of alcohol and hence a renewable raw material. It is relatively less used by the coating chemists due to its relatively limited availability due to restricted uses.

It was found that sorbic acid reacts easily with unsaturated fatty acids. Its solubility in fatty acids and esters is limited. A common solvent that can be removed easily after the reaction was necessary. Cyclohexanone was found to meet this requirement. The resultant half ester of dicarboxylic acid could be easily converted to polyamides for curing epoxies.

The user can manufacture his own dibasic/tribasic acid as a first step. As a source of methyl esters of fatty acids with iodine value about 110 to 130, vegetable oils such as soyabean oil can be used. Low value acid oils obtained from vegetable oil refining are also suitable. Bio diesel could be used directly. To account for large saturated fatty acids in bio diesel, corresponding trimer may be produced by appropriate addition of sorbic acid to fatty acid.

The process allows a manufacturer to develop low cost formulations for bulk products using simple chemistry that can be integrated in the existing process.

The purpose of this paper is to verify, experimentally, the sliding stability of cast polyamide samples under dry sliding in contact with different steel counterface roughnesses. The effect of catalyser (sodium or magnesium) and addition of internal oil or solid lubricants is investigated and a classification for coefficients of friction in relation to the polyamide intrinsic mechanical properties is discussed.

A new tribotester is designed for meso‐scale testing according to the elastic loading region of polymers. The reliability of the tribotester is verified by preliminary determination of the stick‐slip characteristics. Sliding tests for polyamide are done at 1.15‐5.15 N normal load and 0.125‐20 mm/s sliding velocity on steel counterfaces with roughness R_a=4 and 1.6 μm.

Pure polyamides sliding against rough steel show severe stick‐slip. The stick‐slip motion is eliminated in contact with smooth steel counterfaces. Magnesium catalysed polyamide has weaker mechanical properties and shows lower friction with better sliding stability compared to sodium catalysed polyamide. Internal oil lubricant is more efficient in reducing coefficients of friction than internal solid lubricants are. Surface energy measurements are related to coefficients of friction, showing the effect of internal lubrication on adhesion.

Present test results are very specific for the present tribotester configuration and should be further compared to macro‐scale testing. The choice of tribotest conditions strongly affects the sliding performance.

Present tests are done on the meso‐scale, being in between traditional macro‐scale testing and nano‐scale testing. It allows for low contact pressures avoiding the effects of frictional heating and relatively large surfaces areas including the effects of long‐range polymer structure such as internal lubrication.

Anchor Chemical Group PLC (a wholly owned subsidiary of Air Products PLC) has found that use of its Amicure PACM curing agent in heat‐cured, two component adhesives greatly increases the adhesive's high‐temperature performance for plastic or metal bonding. Partial substitution of Amicure PACM curing agent for a standard, high‐imidazoline polyamide in typical adhesive formulations can increase lap shear strength by up to 60 percent. In addition, testing to determine the mode of failure when bonding plastic substrates confirmed the performance benefits of including Amicure PACM curing agent in the adhesive formulation.

Where does the coatings industry look for technology which borders on its own and from which it might derive useful leads and ideas? The coatings industry basically depends on the formation of films. Basic to the idea of coatings is the concept that there must be a film and that this film must derive from the vehicle in the coating. To be sure, the film does not represent the entire coating, but it is the sine qua non; and without a film the coating will neither decorate nor protect. There are a host of other technologies that depend on film formation. When the word ‘film’ is mentioned, adhesives and printing inks come to mind, for these technologies also could not exist without the all‐important phenomenon of film formation.

Magnesium stearate (Mg (C12H33O2)2) is a fine white odourless bulky powder, probably the finest of the metallic stearates, with a very high covering capacity. It has rounder particle shape than does, say, zinc stearate and is a muctuous soapy powder adherent to the skin, and is rated as dermatologically innocuous being neither a sensitizer nor a primary irritant. It can be decomposed by acids, and can exist as the hydrate. Its physical characteristics have been examined closely.

Two reports have recently been published on the state of the adhesives industry, both indicating that growth is currently healthier than either the paints or printing inks industries.

Calcium stearate has many uses, including that of a flatting agent in paint, a lubricant, plasticizer and leveller for paper coatings, suspending agent in plastic and other mouldings, a tableting agent, a water repellant, and a cosmetic component, etc. Gives a complete breakdown and analysis of calcium stearate with a useful Appendix of journal and patent specification.

BEFORE any designer can utilize adhesive bonding in critical structural components he must be able to assure himself of the reliability of the process. This is often'a very difficult procedure since the usual method of testing a joint is to destroy it.

Laporte Australia (Holdings) Ltd. has completed the purchase of Abel Lemon & Co., Pty. Ltd., an Australian chemical distribution business with annual sales of A$50m, from the Adelaide Steamship Co. Ltd. The purchase has been approved by the Australian Government under its foreign investment policy.

Additions for use in polyurethane coatings. Angus Chemie GmbH has announced the introduction of two new additions to its product line for polyurethane coatings. Zoldine RD‐20 Reactive Diluent is designed to replace higher viscosity polyols in high solids polyurethane coatings. Zoldine MS‐Plus Moisture Scavenger eliminates bubbles, pinholes, downglossing and hazing in polyurethane coatings to allow for fast cure times in all types of weather.