Abstract: A heat pump system (10) includes a fluid refrigerant compressor (12) and heat exchanger units (14, 16). Heat transfer tubings (36, 50, 58, 60, 66, 82) interconnect the fluid refrigerant compressor (12) and the heat exchanger units (14, 16) in a series relationship for carrying refrigerant fluid. Flow control valves (22, 24) are provided and are interconnected between a water source (20) and the heat exchanger unit (16) for controlling the amount of water flowing from the water source (20) to the heat exchanger unit (16). The flow control valves (22, 24) are responsive to the pressure at the outlet (12b) of the fluid refrigerant compressor (12) sensed at port (26) in the heat transfer tubing (58) to automatically optimize the operating condition of the heat pump system (10). To further optimize the heat pump system (10) in the heating mode, water from source water (20) flows through preheat exchanger (104) before entering heat exchanger unit (16 ).

Abstract: A polyurethane prepared by reacting specifically identified substituted aromatic diamines with isocyanate-terminated prepolymer. Prepolymer is prepared by reacting polyisocyanate with polymeric polyol. Diamines are required to be selected from specified substituted butylbenzoates, benzonitriles or benzoates. The diamine curative is taught to enhance the processing of the prepolymer/diamine mixture for commercial application.

Abstract: The invention relates to substituted aromatic diamines and polyurethanes cured thereby. The diamines are individually selected from 3,5-diamino-4-tert-alkylbenzoates, 3,5-diamino-4-tert-alkylbenzonitriles and alkylene bis(3-amino-4-tert-alkylbenzoate).

Abstract: The invention relates to substituted aromatic diamines and polyurethanes cured thereby. The diamines are individually selected from 3,5-diamino-4-tert-alkylbenzoates, 3,5-diamino-4-tert-alkylbenzonitriles and alkylene bis(3-amino-4-tert-alkylbenzoate).

Abstract: Thiocarbamates such as N,N-oxydiethylenecarbamyl 1-dodecyl disulfide are used to affect the vulcanization characteristics of sulfur vulcanizable polymers by increasing the state of vulcanization and/or improving scorch resistance and/or increasing the rate of vulcanization.

Abstract: N-(hydrocarbyl thiophosphoryldithio)-imides such as N-(O,O-diisopropyl thiophosphoryldithio)-phthalimide are used as accelerators with, or as a partial or total replacement for, the elemental sulfur used in conventional sulfur vulcanization systems for diene rubbers.

Abstract: Sulfenylthiocarbonates are used to inhibit prevulcanization in rubbers compounded with vulcanization agents. The sulfenylthiocarbonates include methoxycarbonyl 1-dodecyldisulfide; 1,2-bis(methoxycarbonyldithio)-ethane and 1,4-butylenedioxybis(carbonyldithioethane).

Abstract: Tetramethylthiuram tetrasulfide can be prepared in high yields by oxidation of an aqueous solution of dimethylammonium dimethyldithiocarbamate in the presence of carbon disulfide and sulfur. The process is essentially pollution free.

Abstract: Premature vulcanization of rubbers is inhibited by the incorporation therein of a dithioformimidate compound such as methyl N-phenyl-1-(methyldithio)-formimidate.

Abstract: Ureas such as 1,3-bis(morpholinothio)-imidazolidinone are used to affect the vulcanization characteristics of sulfur vulcanizable polymers by increasing the state of vulcanization and improving scorch resistance and/or increasing the rate of vulcanization.

Abstract: An N-(aminothio)-phthalimide such as N-(morpholinothio)-phthalimide is reacted with a compound having the structure RSH or a metallic salt thereof, for example, benzene thiol, to produce a compound having the structure RSSNR.sup.1 R.sup.2, such as N-(phenyldithio)-morpholine. Compounds prepared according to this process are either accelerators or retarders.

Abstract: Ureas such as 1,3-bis(morpholinothio)-imidazolidinone are used to affect the vulcanization characteristics of sulfur vulcanizable polymers by increasing the state of vulcanization and improving scorch resistance and/or increasing the rate of vulcanization.

Abstract: Imides such as N-(morpholinothio)phthalimide are used to affect the vulcanization characteristics of sulfur vulcanizable polymers by increasing the state of vulcanization and/or improving scorch resistance and/or increasing the rate of vulcanization.