When divinylbenzene (DVB) is uled as a crosslinking agent

the introduction of DVB units in a copolymer does not always lead to crosslinkages but results in some pendent double bonds depending on preparative conditions，so that there is a difference between the amount of DVB introduced and the true crosslinking degree(CD)．In this paper，the relative content of the pendent vinyl groups，the true CD and compositions of the macroreticular acrylonitrile-styre-ne-DVB copolymers (MR-PSA resins) have been studied by means of the Fourier Transform Infrared Spectrometer (FT-IR)．The MR-PSA resins were prepared by suspension polymeriza-tion，using the linear polystyrene as a pore-creating agent．In the FT-IR study of the MR-PSA resins．selected absorption bands are：2240 cm-1 (nitrile group)，1636 cm-1 (Ar—c=c，vinyl group of aromatic ring，the characteristic of pendent．double bond)，1510 cm-1 and 836 cm-1 (pata-disubstituted phenyl ring)，802 cm-1 (meta-disubgdtuted phenyl ring)，1494 cm-1 and 760 cm-1 (monosubstutited phenyl ring)．These absorption bands were measured by using integral strength method．Through the calculation for integraf strength ratio of the certain absorption peaks，the relationship between the relative content．of pendent vinyl groups and anlount of DVB applied havo been studied. The change of the true CD of the：MR-PSA resins depending on the amount of DVB have be6u studied，too．