Semi-interpenetrating networks IPNs

Semi-gloss alkyd paint formulation, 18 6 It Semi-interpenetrating network (IPN) approaches, 10 436 Semi-IPN (interpenetrating polymer network) hydrogels, 13 733 Semikilled steels, 23 291 Semimoist pet foods, 10 849 Semipermanent cells, 14 228 Semiphorone, 14 583 Semiportable mri system, 23 860-861 Semiregenerative reforming operations, 25 166... 

There are several interesting applications reported in the literature, such as insulated wire and cable, UV cross-linking of drawn fibers, and tapes from ultra-high-molecular-weight polyethylene. Semi-interpenetrating networks (IPNs) from acrylates and polyurethanes are suitable as UV curable adhesives with high elasticity, good impact resistance, and excellent adhesion to a variety of substrates. ... 

In this research, a novel semi-interpenetrating networks electrolyte has been developed by a solvent-free reactive process. A flexible amorphous polyether modified polysiloxane is incorporated in polyurethane and form semi-interpenetrating network (IPN) structure by in-situ polymerization of polyurethane with the presence of PEMPS and salts. The monomer of polyurethane, polyol, functions as the common solvent to dissolve the salts so no additional volatile solvent is needed in this reactive process. The addition of PEMPS is expected to improve the ionic conductivity of polyurethane due to its high ionic conductivity and the decrease in crystalinity of soft segment of polyurethane as well as the generation of the high conductive interface. 

Interpenetrating network (IPN) A combination of two polymers into a stable interpenetrating network. In a true IPN each polymer is cross-linked to itself, but not to the other, and the two polymers interpenetrate each other. In a semi-lPN, only one of the polymers is cross-linked the other is linear and by itself would be a thermoplastic. The purpose of producing IPN is to improve strength, stiffness, and chemical resistance of certain polymeric systems. 

Extensive research has been conducted and reviewed on interpenetrating polymer networks during the past decade (31-33). IPNs can be categorized into Semi-l-IPN and Semi-2-IPN. Semi-2-IPNs are those in which crosslinkable oligomers or materials are polymerized into the linear matrix. Semi-interpenetrating networks could have combined polymers that have same or different repeating units. 

A commercial blend consisting of a thermoplastic polyamide (PA-6 or PA-66) and 5-25 wt% of a crosslinkable silicone, which forms a semi-interpenetrating network (semi-IPN) upon curing, has been offered under the trade name of Rim-... 

B) Thermoset-thermoplastic blends and semi-interpenetrating networks (Semi-IPN)... 

Far more interesting are, however, those systems which feature conetwork, semi-interpenetrating networks (semi-IPNs), and full IPN structures. 

The idea behind semi-interpenetrating networks (semi-lPN s) is to combine the processabiity of thermoplastics with the high temperature performance of crosslinked thermosetting materials. Such mixtures should possess the desirable features of both types of materials. The majority of semi-IPN s contain continuous phases and the components are immiscible at the molecular level. 

A commercial grade of high-impact (notched Izod > 900 J/m) POM resin (Delrin 100 ST, DuPont) is believed to be a blend of POM with >30 wt% of a thermoplastic poly(ester-urethane) elastomer derived from poly(l, 4-butane adipate) diol and methylene-bis-(4,4 -diphenyl diisocyanate) (MDl) (Hexman 1989). This blend is reported to have a cocontinuous or semi-interpenetrating network of the elastomer in a matrix of the polyacetal (Flexman et al. 1990). The toughening effect in such a blend of IPN-type morphology was interpreted to occur partly through a rubber band mechanism by which the fracture energy is absorbed. The bands of rubbery domains were believed to span the crack and participate in the deformation process. 

In the preparation of semi-interpenetrate network (semi-IPN), collagen can be used as free component or crosslinked to chemicals. Synthesis of semi-interpenetrate network by polymerization reactions is carried out according to the literature data by a few methods, respectively mass polymerization or solution-, suspension-, emulsion-, gas phase- or plasma-induced polymerization. 

Simultaneous and sequential IPNs based on various polymeric systems have been prepared using polydimethylsiloxane (PDMS) as the host network (3-8). These systems include poly(ether-urethane), polystyrene, poly(2,6-dimethyl-1,4-phenyleneoxide), polyacrylic acid, PDMS, polymethylmethacrylate, polyethylene oxide (PEO)... as the guest network. Some semi-interpenetrating networks (s-IPNs) based either on a linear polymer embedded in a polysiloxane network (5,9,10) or on a linear polysiloxane combined with a PEO network (8) have also been described. In some cases, PDMS has been replaced by polyaromatic siloxanes such as polydiphenyl or polymethylphenylsiloxanes (10-12). The focus of this paper concerns the preparation and properties of IPNs and s-IPNs based on polysiloxanes and poly(diethyleneglycol bis-allylcarbonate) (13,14). 

Vidal F, Popp JF, Plesse C, Chevrot C, Teyssie D (2003) Feasibility of conducting semi-interpenetrating networks based on a poly (ethylene oxide) network and poly (3, 4-ethylene-dioxythiophene) in actuator design. J Appl Polym Sci 90 3569-3577 Vidal F, Plesse C, Teyssie D, Chevrot C (2004) Long-life air working conducting semi-IPN/ionic liquid based actuator. Synth Met 142 287-291... 

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