Handbook of Size Exclusion Chromatography and Related ...

Table 2 Molecular Weights of PVP
K value Mw Mn
K-15 7,000–12,000 22,500
K-30 40,000–65,000 210,000
K-60 350,000–450,000 2100,000
K-90 900,000–1,500,000 2360,000
K-120 2,000,000–3,000,000 —
If a K value vs. absolute weight-average molecular weight equation or table
is available for PVP, then the K value can be easily determined from relative
viscosity. Such a relationship, developed by Senak et al., is shown in the equation
log Mw ¼ 2:82 log K þ 0:594 and in Table 3 for commercial grades of
unfractionated PVP (L Senak, CS Wu, EG Malawer, unpublished results). It
should be pointed out here that the K value is a function not only of molecular
weight but also of molecular weight distribution and branching.
2.2 Molecular Weights of VP-Based Copolymers
Most VP-based copolymers are also characterized by K value. However, the
literature on molecular weights of VP copolymers is very sparse. Wu and Senak
reported in 1990 (5) the absolute molecular weights of cationic copolymers of
quaternized vinyl pyrrolidone and dimethylaminoethyl methacrylate by size
Table 3 K Value vs. Weight-Average Molecular Weight for PVP a
K value Mw (AMU) K value Mw (AMU)
10 2,594 70 626,869
15 8,139 75 761,505
20 18,319 80 913,511
25 34,371 85 1,083,831
30 57,475 90 1,273,397
35 88,771 95 1,483,135
40 129,363 100 1,713,957
45 180,326 105 1,966,770
50 242,714 110 2,242,474
55 317,558 115 2,541,955
60 405,870 120 2,866,099
65 508,646
a The calculations are based on the regression formula logMw ¼ 2:82 log K þ 0:594.
© 2004 by Marcel Dekker, Inc.