Addition Of Small Proportion Research Articles

Studies on synthesis of environment-friendly products for paint and coating applications

ABSTRACTIn the study, environment-friendly products, such as ketonic resins were prepared by self-polymerisation of ketonic monomers in the presence of a base catalyst using a high-pressure batch reactor. The cross-polymerisation reactions of ketonic monomers were also examined in the work. The effects of reaction parameters, such as reaction time, temperature, catalyst concentration and monomer concentration on physico-chemical properties of the product, such as physical state, hydroxyl value, iodine value, acid value, viscosity, average molecular weight, solubility, softening temperature and thermal stability have been studied. From the results, it was observed that the polymerisation reactions with methylcyclohexanone (MCH) or cyclopentanone (CP) monomers offered high viscous liquid resins. However, addition of small proportion (5–10 wt%) of MCH or CP along with cyclohexanone (CH) can play a significant role in obtaining a better quality product. It was also observed that CH and MCH monomers offered white colour resins, whereas CP monomer offered brown colour resins. The in-house-developed resins are thermally stable up to a temperature of around 180°C. From the overall investigation, it can be concluded that the in-house-developed ketonic resin products can be a suitable substitute of alkyd, ketone−aldehyde or phenol−aldehyde resins for paint and coating applications.

Mechanical Properties and Metallurgical Characterization of Dissimilar Welded Joints between AISI 316 and AISI 4340

In the present study, the influence of six different process parameters and three interactions on joint tensile strength, toughness, fusion zone microhardness variation are studied during dissimilar tungsten inert gas welding between austenitic stainless steel AISI 316 and alloy steel AISI 4340. Detailed experimental study using fractional factorial experimental design and subsequent statistical analysis show that higher tensile strength, toughness can be achieved using ER 309 filler material and suitably selecting the other process parameters and heating conditions. Addition of small proportion of hydrogen in shielding gas increases the heat transfer efficiency, melting and subsequent penetration. Preheating of AISI 4340 material reduces the chance of solidification cracking and post-heating helps to improve the joint mechanical property. Microstructural observations show that improper selection of process parameters may lead to micro-pores and degrade the joint quality. Successful joining of the dissimilar materials greatly depends on the selection of optimum process parameters, filler material and shielding gas.

Enhancing MUF particleboard adhesives performance by glutaraldehyde addition

Addition of small proportions of glutaraldehyde to MUF resin solids does yield an improvement in both dry internal bond (IB) strength and IB strength after 2 h boiling of the panel, TMA analysis shows that maximum MOE is also increased when small proportions of glutaraldehyde are added.

A study of sensitized explosions. IX. Experimental work on the sensitization of ignitions of hydrogen-chlorine mixtures by chloropicrin

The results of a study of the sensitizing action of chloropicrin upon the hydrogen-oxygen reaction suggested that chloropicrin might also sensitize the hydrogen-chlorine reactions by providing chlorine atoms which would initiate the reaction chains. Experimental work is described which shows that the addition of small proportions of chloropicrin lowers the normal ignition boundary of hydrogen-chlorine mixtures to the temperature range 100 to 200° C. This sensitized boundary separates exceedingly rapid and complete reactions from slow reactions which are further retarded during their course by the formation of nitrosyl chloride from the chloropicrin. At higher temperatures (330 to 370° C) the decomposition of the chloropicrin is sufficiently rapid for the inhibiting action of the nitrosyl chloride to become prominent during the entry of the gases, and the ignition boundary rises with increasing temperature. It rises more sharply with a greater proportion of chloropicrin in the mixtures entering the vessel, and when a longer portion of the entry tube is heated. The sensitized ignitions are suppressed by the addition of small quantities of nitrosyl chloride. A remarkable ‘backfire’ phenomenon, in which ignitions travel back to the cold mixing vessel but not into the hot reaction vessel, is described and shown to be in agreement with the assumption that reaction chains are started by chlorine atoms formed from chloropicrin and are abruptly terminated by nitrosyl chloride also formed from chloropicrin. Experimental work upon the effects of nitrosyl chloride upon the boundary of ignition of mixtures of hydrogen and chlorine show that below 400° C it acts as an inhibitor, but above 400° C it has a slight sensitizing effect.

THE EFFECT OF CHARCOAL ON THE GROWTH OF LEGUMINOUS PLANTS IN SAND CULTURE

The addition of small proportions (0.5‐2.0 %) of activated charcoal to the rooting medium of inoculated peas in nitrogen‐free sand culture resulted in marked increases in dry weight of the plants and in nitrogen fixation. Wood charcoal in larger proportions had a similar effect, while animal charcoal severely inhibited growth. The number of nodules was greatly reduced in the presence of activated charcoal, but such nodules as formed were much larger and the nodule tissues per unit weight were more active in nitrogen fixation. Activated charcoal also led to an increase in dry weight of non‐inoculated peas supplied with inorganic combined nitrogen. It is tentatively suggested that these favourable effects arise from the adsorption by the charcoal of harmful excretions from roots or micro‐organisms or of excess nutrients, and from the maintenance of a more favourable pH in the rooting medium. The examination of barley intersown with the peas, and the results of Kjeldahl analyses on the rooting media, provided no evidence that the enhanced fixation in the presence of activated charcoal was attended by any considerable excretion of fixed nitrogen.