Acrylamide/2-acryloxyethyltrimethyl ammonium chloride copolymers in inverse microemulsion, with a cationic charge density of 60% and a concentration of active matter of 30 wt %, of interest as flocculants have been obtained by inverse microemulsion copolymerization. Interesting inverse microemulsion formulations from both industrial and economical standpoints were selected from pseudoternary phase diagrams. These formulations were polymerized by semicontinuous free radical copolymerization in inverse microemulsion using sodium disulfite and ammonium persulfate as initiators. Influence of initiators and initiator addition conditions (specific flow rate and concentration) on semicontinuous polymerization and final product properties as flocculants have been studied. A strong difference in copolymer solution viscosity has been found when an aqueous solution of sodium disulfite is used as initiator instead of sodium disulfite/ammonium persulfate couple redox, specially for low sodium disulfite solution feeding flow.

This study analyzes real experiences of culture management to better understand how ethics permeates organizations . In addition to reviewing the literature, we used an action-research methodology and conducted semistructured interviews in Spain and in the U.S. to approach the complexity and challenges of fostering a culture in which ethical considerations are a regular part of business discussions and decision making. The consistency of findings suggests patterns of organizational conditions, cultural elements, and opportunities that influence the management of organizational cultures centered on core ethical values. The ethical competencies of leaders and of the workforce also emerged as key factors. We identify three conditions—a sense of responsibility to society, conditions for ethical deliberation, and respect for moral autonomy—coupled with a diverse set of cultural elements that cause ethics to take root in culture when the opportunity arises. Leaders can use this knowledge of the mechanisms by which organizational factors influence ethical pervasiveness to better manage organizational ethics.

ABSTRACT:The semicontinuous inverse microemulsion copolymerization of 80/20 wt % [2-(acryloyloxy)ethyl]trimethylammonium chloride/acrylamide in an isoparaffin solvent at high comonomer concentrations (30-42 wt %) was studied with a mixture of nonionic surfactants (Crill 43 and Softanol 90) as the emulsifier and sodium metabisulfite as the initiator. The influence of the total comonomer concentration (TCC), emulsifier concentration (EC), hydrophilic-lipophilic balance (HLB), isopropyl alcohol (chaintransfer agent) concentration (IPC), and crosslinking agent concentration (CAC) on the weight-average molar mass (M w ), absolute viscosity (BV), and viscometric structuring index (VSI) of the obtained copolymers was analyzed. M w and BV increased with TCC and HLB and decreased with EC. At the higher TCC, M w decreased with IPC; meanwhile, at the lower TCC, M w increased with IPC above 0.5 wt %. VSI increased with TCC, HLB, and IPC and decreased with EC. VSI increased dramatically with CAC, whereas BV showed a peak at the CAC of 10 ppm. In the absence of both chain-transfer and crosslinking agents, M w increased linearly with VSI, and this suggests that linear copolymers of very high M w values cannot be obtained by inverse microemulsion copolymerization, at least for high TCCs. The results are explained in terms of both the collapsed state of the copolymer chains inside the latex particles and changes in the interface structure and composition.

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The influence of initiator concentration, specific flow rate of initiator addition (Qsp), initial copolymerization temperature (Ti), aqueous phase pH and total comonomer concentration (TCC) on flocculating performance of latex particles of acrylamide and [2- (acryloyloxy)ethyl]trimethylammonium chloride copolymers with a cationic charge density of 40%, obtained by inverse microemulsion copolymerization by using a surfactant blend of Arlacel 83 and Softanol 90 as emulsifier and Rolling M-245, a mixture of n-decane and n-tetradecane in about 40/60 weight ratio, as oil phase, has been studied for high TCC, ranging from 28 to 34.5% (w/w). Comonomer inverse microemulsion copolymerizations were carried out in the semicontinuous mode by adding continuously an aqueous solution of sodium metabisulfite as initiator into stirred inverse comonomer microemulsions. Initiator concentration has a strong influence on viscosity, viscometric structuring degree (VSI) and average weight molar mass (Mw) of copolymers in the range from 5 to 25 g/L. Both viscosity and Mw decrease with increasing initiator concentration. Best flocculating performance is obtained from 10 to 20 g/L, values at which VSI shows a minimum. Under the experimental conditions used, Qsp (153 to 310 mL/h/kg of comonomer), Ti (25 to 35ºC) and aqueous phase pH (2.5 to 4.5) have almost no influence on both viscosity and VSI and, hence, on flocculating performance. On the contrary, TCC has a slight influence on copolymer viscosity but a strong one on VSI which increases dramatically with TCC, being the worst flocculating performance obtained at the highest TCC studied (34.5% (w/w)). Flocculating performance results are explained in terms of copolymer structuring degree and collapsed state of copolymer chains inside latex particles as well as in terms of the composition drift with conversion.