Networks, simultaneous interpenetrating

Simultaneous Interpenetrating Networks Based on Castor Oil Elastomers and Polystyrene A Review of an International Program... 

The first type, termed sequential IPN s, involves the preparation of a crosslinked polymer I, a subsequent swelling of monomer II components and polymerization of the monomer II in situ. The second type of synthesis yields materials known as simultaneous interpenetrating networks (SIN s), involves the mixing of all components in an early stage, followed by the formation of both networks via independent reactions proceeding in the same container (10,11). One network can be formed by a chain growth mechanism and the other by a step growth mechanism. 

Special Functional Triglyceride Oils as Reactive Oligomers for Simultaneous Interpenetrating Networks... 

Castor oil and styrene were polymerized to make simultaneous interpenetrating networks. On reaction, the materials phase separate and sometimes phase invert. 

Simultaneous Interpenetrating Networks. An interpenetrating polymer network, IPN, can be defined as a combination of two polymers in network form, at least one of which was polymerized or synthesized in the presence of the other (23). These networks are synthesized sequentially in time. A simultaneous interpenetrating network, SIN, is an IPN in which both networks are synthesized simultaneously in time, or both monomers or prepolymers mixed prior to gelation. The two polymerizations are independent and non-interfering in an SIN, so that grafting or internetwork crosslinking is minimized (23-26). 

In the simultaneous interpenetrating networks (SIN), the two reactions are run simultaneously. This reaction will be emphasized in the present paper. One reaction, for example, can be a polyesterification or a polyurethane stepwise reaction, while the other is an addition reaction using styrene to make polystyrene via free radical chemistry. 

Figure 1. The synthesis of sequential IPN above and simultaneous interpenetrating networks, SIN, below. For the synthesis of SIN, two different reactions operate simultaneously such as condensation polymerization and addition polymerization. Reproduced with permission from Ref. 23. Copyright 1981, Plenum Publishing.

Interpenetrating polymer networks are defined in their broadest sense as an intimate mixture of two or more pol)Mners in network form [1,2]. Ideally, they can be synthesized by either swelling the first crosslinked polymer with the second monomer and crosslinker, followed by in-situ polymerization of the second component (sequential IPN s) or by reacting a pair of monomers and crosslinkers at the same time through different, non-interfering reaction mechanisms, simultaneous interpenetrating networks, SIN s. In fact, many variations of these ideas exist in both the scientific and the patent literature. In any case, at least one of the two components must have a network structure, as an IPN prerequisite. ... 

These reactions can also be used to form networks that interpenetrate,18,237,261-267 as illustrated in Figure 4.10.237 For example, one network could be formed by a condensation end-linking of hydroxyl-terminated short chains and the other by a simultaneous but independent addition end-linking of vinyl-terminated long chains. Interpenetrating networks are of interest because they can be unusually tough, and could have unusual dynamic mechanical properties. 

The cyanates are mixed with thermoplastic polymers. They can be also dissolved in a monomer and then a simultaneous polymerization is carried out. So-called SINs (Simultaneous Interpenetrating Networks) are obtained. 

Jordhamo GM, MansonJA, Sperling LH (1986) Phase continuity and inversion in polymer blends and simultaneous interpenetrating networks. Poly Eng Sci 26 517... 

Zhou P, Xu Q, Frisch HL (1994) Kinetics of simultaneous interpenetrating polymer networks of poly(dimethylsiloxane-urethane)/poly(methyl methacrylate) formation and studies of their phase morphology. Macromolecules 27(4) 938-946... 

In other cases, it may be important to indicate that the mixing or reactions were carried out simultaneously. This will be indicated, where necessary, by brackets. See example in Equation 18. This indicates a simultaneous interpenetrating network, where Cu was formed by one... 

Simultaneous Interpenetrating Networks Based on Epoxy/Acrylic Materials... 

Simultaneous interpenetrating networks (SIN s) are produced by running two essentially independent and noninterfering, crosslinking... 

---