Chapter 13 423 Table 1. Structure-function relation of an advanced styling polymer Monomer Feature Benefits VCL Film stiffness, hydrophobicity Flexibility, durability of hold, shine VP Film stiffness Initial stiffness and scrunch DMAPMA Film smoothness Conditioning, flexibility MAPLDAC Cationic, hydrophobic Conditioned feel, associative behavior Table 2. Effect of copolymerization on important hair attributes Attribute/Polymer Homopolymer of VP (PVP) Tetrapolymer of VP (Polyquaternium-69) Clarity in carbomer 3 3 Stiffness 3 3 Stiffness durability ─– 3 Reduced flaking ─– 3 High humidity curl retention ─– 3 Shine ─– 3 Smooth feel ─– 3 An example of making a VP type of polymer more hydrophobic is copolymerizing with hydrophobically modified acrylates (AA) as is evident in VP/acrlyates/lauryl methacrylate copolymer9 this structure is depicted in Figure 2. The VP and AA moieties of the polymer provide for the primary stiffness and water solubility properties of the resin. The hydrophobicity provides multifunctional benefits such as enhanced hold at high humidity, low tack and flaking, and association with hydophobically modified gellants. Figure 2. Structure of VP/Acrylates/Lauryl Methacrylate Copolymer