Stimulus type temperature-responsive polymers

Depending on the nature of the grafted chains, the membrane-brush system responds to a specific type of stimulus. Known types of stimuli-responsive polymers are PAA, which has a transition between the collapsed and swollen state around pK , and PNlPAAm, which has a pronounced tendency to swell and deswell as a function of temperature. Essentially numerous combinations can be envisioned for the fabrication of concave brushes with diverse properties, including multiblock grafted polymers [45] or mixed brushes that are sensitive to multiple stimuli [36]. 

Recently, Lendlein et al. created a series of responsive shape memory polymers which are mechanically tough, biocompatible, and biodegradable, applicable to a number of biomedical apphcations [300,301,305]. Such shape memory polymers are achieved by copolymerizing precursors with different thermal characteristics such as the melting transition temperature. These shape memory polymers can be deformed into a temporary compressed state and they can recover the permanent shape only with the aid of an external stimulus such as temperature. This type of ape memory polymer mainly consists of two components (i) molecular switches—precmsors that can imdergo stimuh responsive deformation and can fix the formed tempo-... 

Shape-memory polymers (SMP) are stimuli-responsive. They have the capability of recovering their shape npon the application of an external stimulus. This external stimulus can be heat or an electrical voltage if the material shows electrical conductivity. Thermoplastic polyurethanes with SMP behavior were discovered at Mitsnbishi Co. in 1988. However, it was since 1996 that their investigation turned out to be more systematic." In this type of TPU, hard segments act as cross-links and are responsible for the permanent shape. Above the melting temperature of the hard segment domains, the polymer can... 

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