What are hydrophobically associating polyacrylamides (hapams)?

Of particular interest in this class are hydrophobically associating polyacrylamides (HAPAMs), derived from polyacrylamide by introducing a relatively low amount (generally less than 2 mol%) of hydrophobic pendent groups .

Is cationic polyacrylamide hydrophilic?

However, a cationic polyacrylamide itself contains a large number of hydrophilic amide groups that cannot drive the transformation of surface water adsorbed on and absorbed in the sludge flocs into free water that can be separated and removed.

Why are hydrophobically modified polyelectrolytes more important than hhapams?

For hydrophobically modified polyelectrolytes like HHAPAMs, this is more important since there are two opposing effects existed simultaneously: hydrophobic aggregation and Colombic repulsion.

How to determine charge content in partially hydrolyzed polyacrylamides?

3.2.2. Hydrolysis degree Potentiometric titration is a classical way to determine charge content in partially hydrolyzed polyacrylamides . However, for the partially hydrolyzed HAPAMs used in this work, we found very limited solubilities when they are in the acid form after exchange with cationic resin.

Are hydrophobically modified polyelectrolytes suitable for hydrolysis?

The literature data for HPAMs are usually only suitable for a certain hydrolysis degree rather. For our series of hydrophobically modified polyelectrolytes, the comparison of their molecular weights appears difficult because there are no k and α values available for their Mark–Houwink relationship.

How is acrylamide polymerized?

A given amount (0.25 mol, 17.77 g) of acrylamide was dissolved in 500 ml water followed by 30 min purified nitrogen purge. 2.5 ml of 0.1 mol l −1 KPS and TMEDA aqueous solutions were then injected successively. The polymerization was conducted at 30.0±0.1 °C with a thermostatically controlled water circulating bath.