Polyisobutylene succinic anhydride (PIBSA) is an important intermediate for ashless dispersant additives used in lubricant formulations, where conversion and exo-selectivity strongly influence product performance. In this work, the thermal synthesis of PIBSA derived from highly reactive polyisobutylene (HR-PIB) 1300 and 2300 was systematically investigated using a full factorial experimental design to evaluate the effects of feed molar ratio, reaction temperature, and stirring rate on conversion and exo-PIBSA yield. Structural confirmation was performed using ¹H NMR spectroscopy, gel permeation chromatography (GPC), and saponification value analysis. HR-PIB 1300 achieved conversions of 60–94%, while HR-PIB 2300 achieved conversions of 75–88% under the investigated conditions. A clear molecular-weight-dependent trade-off between conversion and exo-selectivity was observed. For PIBSA 1300, higher temperatures increased conversion but reduced selectivity, resulting in exo-PIBSA yields of 24–56%. In contrast, PIBSA 2300 achieved yields of up to 71%, highlighting the importance of mixing and mass-transfer effects in higher-viscosity systems. These findings demonstrate that optimal thermal maleation conditions are strongly dependent on polymer molecular weight and provide mechanistic insight for future optimization of industrial PIBSA production.

Membrane contactors allow for higher mass transfer per unit volume. Hence, there has been great interest in recent years on its development and applications in separation processes. It offers high interfacial area between liquid and gas phases while preventing direct mixture, and concurrently prevents flooding and foaming, thanks to the independent gas and liquid flow rates. However, wetting of the membrane pores is a serious problem for this technology application, where even partial membrane pores wetting could significantly deteriorate contactor performance. Therefore, it is crucial that the membranes are hydrophobic to maintain membrane nonwetting during operation. Moreover, any membrane surface modification to increase its hydrophobicity must also be highly stable, does not leach out, and can be applied for long-term operation. This chapter looks at the research done on superhydrophobic membranes for gas-liquid membrane contactor application and its recent advances.