Luc Elza Florent Leemans

Reactive blending of poly(styrene-co-maleic anhydride) with poly(phenylene oxide) by addition of α-amino-polystyrene

-(3-Aminopropyl-l-amino)polystyrene (-amino-PS) was melt-blended with styrene/maleic anhydride copolymers (SMA) containing 28 wt% maleic anhydride groups. The terminal primary amino group can react with the maleic anhydride monomer units in SMA, forming imides. The resulting product turned out to be an efficient emulsifier for SMA blends with poly(phenylene oxide) (PPO). At constant weight fraction of added -amino-PS, the size of the dispersed PPO particles decreased with decreasing molar mass, i.e. increasing mole fraction, of the -amino-PS. In a second series of experiments, -amino-PS with , was used to compatibilize SMA/PPO blends which also contained poly(acrylonitrile-co-butadiene-co-styrene) and some poly[styrene-b-(ethylene-co-butylene)-b-styrene] triblock copolymer. Although, in this case, it was not possible to detect major changes in the phase texture or morphology, it could be shown that the addition of -amino-PS improved the impact strength significantly. For comparison, blends were also prepared with unmodified PS of a similar . No corresponding improvement of the mechanical properties was observed in this case.

Hydroboration/amination of EPDM with dicyclopentadiene as diene monomer

Abstract EPDM containing dicyclopentadiene (DCPD) as diene monomer was hydroborated with 9-borabicyclo(3.3.1)nonane (9-BBN). The subsequent amination with monochloroamine was expected to result in EPDM with primary amine groups. The conversion of the residual unsaturation of DCPD of EPDM was complete, but the chemical structure of the amine-modified EPDM could not be fully elucidated. Hydrogenated DCPD (DCPDH), the low-molecular-weight analogue of DCPD incorporated in EPDM, was also hydroborated and aminated and the resulting product was isolated and extensively characterized. It was shown to consist of DCPDH coupled to 9-BBN via the B-atom with an NH unit inserted in one of the B–C bonds of the 9-BBN unit. The product is in fact a zwitterion RR′B−(OH)NH2+R″, which converts to the neutral RR′BNHR″ upon dehydration. Using the analytical data of the low-molecular-weight product it was deduced that a similar structure is present in the amine-containing EPDM. Surprisingly, both amine-modified EPDM and DCPDH reacted as primary amines; for example, in the presence of anhydrides imides were formed. Finally, application of the amine-containing EPDM resulted in compatible blends of EPDM with poly(styrene-co-maleic anhydride).