将IR法和1H-NMR法相结合,可以测定SBS中1,4-PB和1,2-PB的相对含量。本法不必测定溶液的准确浓度和液体池厚度,具有简便、快速的特点。在35℃、SBS浓度为3.0mg/mL环己烷、转速为56100,/min的条件下,用超离心沉降法测得线形SBS的沉降系数(S)随聚苯乙烯含量(WPS)的增加而增加。当WPS<50％(质量)时,S~(-1)=0.97-0.010 WPS;当WPS>50％时,1nS～1nWPS呈直线关系。国产SBS中不含两嵌段共聚物,1,2-PB含量比国外产品约高6％。 By combining IR and 1H-NMR methods, the relative amounts of 1,4-PB and 1,2-PB in SBS can be determined. This method does not have to determine the exact concentration of solution and liquid pool thickness, with simple, fast features. The sedimentation coefficient (S) of linear SBS with the increase of polystyrene content (WPS) was measured by ultracentrifugation at 35 ℃, cyclohexane at SBS concentration of 3.0mg / mL and rotational speed of 56100rpm Increase. S -1 -1 = 0.97-0.010 WPS for WPS <50% by mass, and 1 nS -1 nWW for WPS> 50%. Domestic SBS does not contain two diblock copolymer, 1,2-PB content of about 6% higher than foreign products.