Despite some pitfalls in the practical application of the gas assisted injection moulding (GAIM) process, it offers a number of advantages over conventional injection moulding. However, its inherent complexity requires an advanced control over several additional parameters. This study is preliminar to examine the gas void and its relation to channel geometry and processing conditions for differ...

In the past decade, supercritical fluid chromatography (SFC) has experienced a steady growth in acceptance, particularly in pharmaceutical and chemical laboratories. In SFC, a “supercritical” fluid, most commonly CO2, in combination with one or more polar organic solvents, such as alcohols, is used as mobile phase. Compared to HPLC, SFC offers better selectivity and shorter analysis time due to...

In this paper six new copoly(amide-imide)s (7a-f) were synthesized through the direct polycondensation reaction of N,N'-(4,4'-diphenylsulfone)bistrimellitimide (1) with 4,4'-diamino diphenylsulfone (2), 4,4'-diamino diphenylether (3), in the presence of adipic acid (4), fumaric acid (5) or terephthalic acid (6) as the second diacid in a medium consisting of N-methyl-2-pyrrolidone, triphenyl pho...

This paper targets an inherent control of optical shrinkage in photosensitive polymers, contributing by means of spatially resolved analysis of volume holographic phase gratings. Point by point scanning of the local material response to the Gaussian intensity distribution of the recording beams is accomplished. Derived information on the local grating period and grating slant is evaluated by ma...

nowdays, production of high quality engine oils is one of the worries of our country’s engine oil industry. in this study, the behavior of four commercial polymers used in nation motor oil industry in obtaining the best viscosity index improver was investigated. in this regard, viscometric behavior, shear stability and polymers’ performance for engine cranking were compared at low temperature. ...