CROSS-LINKED POLYSTYRENE WITH IMPROVED MECHANICAL-PROPERTIES

The synthesis of some divinyl monomers-bis(vinylphenyl)ethane (2), bis-(vinylbenzyloxy)hexane (3a), and bis(vinylbenzyloxy)dodecane (3b) is reported. Copolymers of the new monomers and styrene were evaluated as an alternative to divinyl-benzene-crosslinked polymers for use as matrices and absorbents. The mechanical properties and the amount of residual double bonds in the copolymers were compared. It was found that the new copolymers, unlike the divinylbenzene-crosslinked polymers, retained their mechanical strength even at high crosslinking degrees. Stress at break values of 79, 68, and 18 N/mm2 were found for the polymers crosslinked with 20 mol % of 3a, 2, and divinylbenzene; 5, 25 and 45% of the divinyl units in these polymers were left as pendant double bonds. Porous styrene-2 copolymers were synthesized and shown to have lower surface areas than the corresponding divinylbenzene-crosslinked polymers. The pore size distribution showed that this was due to the absence of the smallest pores which are found in the divinylbenzene-crosslinked polymers in between heavily crosslinked nodules. (C) 1993 John Wiley & Sons, Inc.