Influence of rubber content on static and dynamic properties of polystyrene

Mechanical properties, deformation modes under both uniaxial tension and compression, low temperature mechanical relaxation behavior, and resistance to fracture under dynamic loading have been investigated for a medium impact grade of polystyrene, Shear yielding is the dominant mode of plastic deformation in compression while matrix crazing, together with some tearing and cavitation of the rubber phase, occurs in tension. The craze microstructure, as determined by transmission electron microscopy (TEM), is typical of that noted in polystyrene, with sharp craze-bulk interfaces and a characteristic midrib section. The presence of a third phase, possibly a processing aid, is evident in the TEM scans and in the dynamic mechanical data. The present data, together with the data obtained on polystyrene and on high impact polystyrene, are used to show the strong influence of rubber content on various mechanical properties, such as the tensile craze yielding stress, ductility, compression yield strength, degree of strain softening, and fatigue durability.     

Charging performance of automotive batteries—An underestimated factor influencing lifetime and reliable battery operation

Dynamic charge acceptance and charge acceptance under constant voltage charging conditions are for two reasons essential for lead-acid battery operation: energy efficiency in applications with limited charging time (e.g. PV systems or regenerative braking in vehicles) and avoidance of accelerated ageing due to sulphation. Laboratory tests often use charge regimes which are beneficial for the battery life, but which differ significantly from the operating conditions in the field.     

Sulfochlorierung von 1,2-Naphthochinondiazid-(2) mit Chlorsulfonsäure

Sulfochlorination of 1,2-Naphthoquinone-(2)-diazide by Chlorosulfonic acid . The sulfochlorination of 1,2-naphthoquinone diazide-(2) ( 1 ) by chlorosulfonic acid was investigated. The yields of the formed products (1,2-naphthoquinone diazide-(2)-4-sulfonic acid ( 4 ), 1,2-naphthoquinone diazide-(2)-5-sulfonic acid ( 5 ), 1,2-naphthoquinone diazide-(2)-4-sulfochloride ( 2 ) and 1,2-naphthoquinone diazide-(2)-5-sulfochloride ( 3 )) depend on the temperature and on the time of reaction. The highest yields of the favoured 1,2-naphthoquinone diazide-(2)-4-sulfochloride ( 2 ) are obtained at 63°C and after a reaction time of 80 minutes (50%).     

Regeneration of a Strong Acid Cation Exchange Resin for Deionizing Corn Syrup Solutions

The influence of regenerant flowrate and concentration on regeneration capacity of cation exchange resins used in refining corn syrups was investigated. A strong acid exchange resin (Duolite C-26®) was examined over a range of resin compositions. Co-current regeneration was modeled using hydrochloric acid at dosages ranging from 64 to 256 g/I (4 – 16 lb/cu. ft.). Resin beds exhausted with large amounts of calcium (and other divalent ions) are best regenerated at high acid concentrations and low regenerant flowrates. Resin beds with large amounts of sodium and/or other monovalent ions are most efficently regenerated at low acid concentrations. Flowrate has little influence on regeneration with large amounts of sodium. Syrup deionized prior to isomerization typically has a lower divalent ion content than syrup deionized after isomerization. This suggests that two separate procedures may be necessary in order to most effectively use the regenerant.