Redirecting research efforts on the diversification-performance linkage: The search for synergy

We review the literature on the diversification-performance (D-P) relationship to a) propose that the time is ripe for a renewed attack on understanding the relationship between diversification and firm performance, and b) outline a new approach to attacking the question. Our paper makes four main contributions. First, through a review of the literature we establish the inherent complexities in the D-P relationship and the methodological challenges confronted by the literature in reaching its current conclusion of a non-linear relationship between diversification and performance. Second, we argue that to better guide managers the literature needs to develop along a complementary path – whereas past research has often focused on answering the big question of does diversification affect firm performance, this second path would focus more on identifying the precise micro-mechanisms through which diversification adds or subtracts value. Third, we outline a new approach to the investigation of this topic, based on (a) identifying the precise underlying mechanisms through which diversification affects performance; (b) identifying performance outcomes that are “proximate” to the mechanism that the researcher is studying, and (c) identifying an appropriate research design that can enable a causal claim. Finally, we outline a set of directions for future research

Monolithic aerogels based on poly(2,6-diphenyl-1,4-phenylene oxide) and syndiotactic polystyrene

Molecular sorption behavior of amorphous and semicrystalline samples based on poly(2,6-diphenyl-1,4-phenylene oxide) (PPPO) has been compared. Fully amorphous PPPO powders, as obtained by supercritical carbon dioxide (scCO2) extraction of concentrated solutions, present uptake of pollutants much higher than for commercial sorbent materials based on semicrystalline PPPO (Tenax TA). Robust monolithic aerogels with good handling characteristics can be easily obtained by solvent extraction by scCO2 from gels including PPPO blends with syndiotactic polystyrene (s-PS). These monolithic PPPO/s-PS aerogels present many advantages as sorbent materials with respect to both amorphous and semicrystalline PPPO powders. In fact, besides the obvious advantages in terms of easier and safer handling, the new monolithic aerogels present higher surface areas and equilibrium guest uptakes