Average bond strength of second generation dentin bonding agents:
SECOND GEN - Contains halophosphorus esters of unfilled resins.
Mechanism of bonding Is by ionic bond to calcium by chlorophosphate groups.
Eg: scotchbond, bondlite. 
Disadvantages: 

Again poor bond strength 2-5 MPA. 
Hydrolysis of bond. 
Bonds to smear layer.  

Reference-Sturdevant 6th ed  Pg: 116
2-5 MPA
12-18 MPA
20-23 MPA
25-30 MPA