Palm tree polymer

Different types of LCB are distinguished. Star polymers are the simplest branched polymers because they have only one branch point. Regular star polymers have a branch point with a constant number (functionality,/) of arms and every arm has the same molecular weight. They are therefore monodisperse polymers. Star polymers may also have arms with a most probable distribution [5], Star polymers can also be polydisperse due to a variable functionality. Palm tree [6] or umbrella polymers [7] that contain a single arm with different molecular weight (MW) than the other arms are classified under the asymmetric star [8] polymers, see Figure 3.2. 

Figure 3.2 Regular star polymers with f= 3 and f=6 and an asymmetric palm tree or umbrella polymer.

By this way, polymers with Janus-type, sphere-type bottle brush-type shapes, or dumbbell-like, palm-tree-like contours were derived with excellent control and precise topological features. 

Nanocellulose-reinforced acrylate latex can also be an interesting material for the surface coating industry. Mabrouk et al. [57] used an one-step miniemulsion polymerization method to prepare stable aqueous nanocomposite dispersions based on cellulose whiskers extracted from the rachis of the date palm tree and a poly (styrene-co-2-ethyl hexylacrylate) copolymer. A reactive silane, i.e., methacryloxypropyl triethoxysilane (MPS) was added to stabiHze the dispersion and favor the anchoring of the whiskers on the polymer particles. The particle size of the polymer dispersion ranged between 90 and 160 nm for a whisker content varying from 1 to 5 wt%. 

Figure 5.10 Evolution of the polymer particle size as a function of the date palm tree cellulose whiskers content in the dispersion. Reproduced from [57] with permission of Wiley.

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