Interpenetrating polymer networks semi-IPNs

With controllable strength of the self- and hetero-associated hydrogen, a molecular level penetrated semi-interpenetrating polymer networks (semi-IPNs) of ST-VPDMS with poly(N-vinylpyrrolidone) (PVPr) were prepared by condensation of the self-associated silanols.13... 

Semi-interpenetrating Polymer Network (Semi-IPN) Synthesis ... 

When monomer 2 is swollen into network 1 and polymerized in situ to form a linear polymer, a semi-interpenetrating polymer network (semi-IPN) of the first kind arises (18,19, 20, 21, 22). The first kind denotes that the first polymer synthesized forms the network (Figure 5A). A semi-IPN of the second kind denotes that the first synthesized polymer is linear and the second synthesized polymer is crosslinked (23-25). If polymer 1 is linear and polymer 2 is crosslinked, the structure in Figure 5B arises. In general, polymerizing 2 first and then 1, yields quite... 

Semi-interpenetrating polymer networks (semi-IPN, also called pseudo-IPN)... 

Hao et al. [30] obtained a semi-interpenetrating polymer network (semi-IPN) based on linear PCL (1-PCL) and the PCL network (net-PCL) in which HAp nanocrystals were homogeneously dispersed. The preparation process of semi-IPN (l-PCL/net-PCL)/HAp is shown in Fig. 18. 

Another class of cross-linked networks incorporating NLO chromophores based on a semi-interpenetrating polymer network (semi-IPN) [105] and fully interpenetrating polymer networks (full-IPN) [106-108] has been investigated. These systems were developed to enhance temporal stability by realizing the ability of an IPN structure to improve the viscoelastic properties of polymers. The semi-IPN system was prepared by combining a high 7g polyimide and a sol gel network [105]. The poled semi-IPN sample has a of 28 pm/V at 1.064 /x,m. After over 168 h at 120°C, a retention of 13% of the d value was observed. 

Fu et al. [124] prepared a series of novel covalent organic-inorganic hybrid proton-conductive membranes, each with a semi-interpenetrating polymer network (semi-IPN), for DMFC applications through polymer reactions and sol-gel method. A sulfonation reaction was produced as last step. The developed copolymer chains interpenetrated into the PVC matrix to form the semi-IPN structure, and the inorganic silica was covalently bound to the copolymers. 

Perfluorinated sulfonic acid polymers, such as Nafion membranes, were the most commonly used materials in practical systems for their high proton conductivity and extremely high oxidative stability. However, due to the poor dimensional stability, low mechanical properties of Nafion at high humidity and high temperature, and high cost, an essential need for cost-effective and reinforced substitutes with improved performance arises [193-195]. Nafion blended with the second component could not only reduce the cost, but also improve the mechanical properties and the dimensional stability. Recently, the reinforced composite membranes based on semi-interpenetrating polymer network (semi-IPN) structures of Nafion , polyimidazole (PI) [196-198], polybenzimidazole (PBI) [199], and poly(vinyIidene fluoride) (PVDF) [200] were reported. As shown in Fig. 2.35, the composite membranes with... 

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