Interpenetrating polymer networks latex

Sheu and coworkers [111] produced polysty-rene-polydivinylbenzene latex interpenetrating polymer networks by the seeded emulsion polymerization of styrene-divinylbenzene in the crosslinked uniform polystyrene particles. In this study, a series of uniform polystyrene latexes with different sizes between 0.6 and 8.1... 

Viscoelastic Properties of Acrylic Latex Interpenetrating Polymer Networks as Broad Temperature Span Vibration Damping Materials... 

Ibf pound-force LIPN latex interpenetrating polymer network... 

J. A. Grates, D. A. Thomas, E. C. Hickey, and L. H. Sperling, Noise and Vibration Damping with Latex Interpenetrating Polymer Networks, /. Appl Polym. Sci. 19(6), 1731 (1975). Latex IPNs for sound damping. Methacrylic/acrylic compositions. 

L. H. Sperling, T.-W. Chiu, C. P. Hartman, and D. A. Thomas, Latex Interpenetrating Polymer Networks, Polym. Prepr. Am. Chem. Soc. Div. Polym. Chem. 13(2), 705 (1972). Damping properties of latex IPNs based on methacrylic/acrylic compositions. 

Hyperbranched polyurethanes are constmcted using phenol-blocked trifunctional monomers in combination with 4-methylbenzyl alcohol for end capping (11). Polyurethane interpenetrating polymer networks (IPNs) are mixtures of two cross-linked polymer networks, prepared by latex blending, sequential polymerization, or simultaneous polymerization. IPNs have improved mechanical properties, as weU as thermal stabiHties, compared to the single cross-linked polymers. In pseudo-IPNs, only one of the involved polymers is cross-linked. Numerous polymers are involved in the formation of polyurethane-derived IPNs (12). 

Thus the microstructure and the bonding between phases are profoundly affected by the presence of a polymer, especially a film-forming polymer. Further studies of the adhesive and morphological characteristics should make it possible to improve the efficiency of the polymer still further. A somewhat analogous dispersion of rubber latex particles in a plastic matrix is discussed in Section 3.2.2 the related interpenetrating polymer networks discussed in Chapter 8 should also be mentioned. 

It has been shown in this chapter that the MTDSC technique is a very useful tool in the study of several aspects of polymer blends and related materials including structured latexes and interpenetrating polymer networks. It is important to note that the dCp/dT versus temperature signal may be used not only qualitatively as a sensitive detector of transitions impossible to spot by other thermal techniques such as conventional DSC and DMTA, but it may also be used to significant advantage in a quantitative way. It has been shown that it is sensitive to the diffuse interface between phases. Thus, from dCp/dr versus temperature signals, the weight fraction of the diffuse interface can be quantified. There are many situations where this will prove to be very valuable. 

Interpenetrating polymer network (IPN) Polymer alloy, containing two or more polymers in the network form, each chemically cross-linked. Sequential, simultaneous (SIN), and latex type IPNs are known... 

The above represents the classical definition of an IPN. The term interpenetrating polymer network was coined before the extent or conseqnences of phase separation were fully realized. This article covers sequential and simultaneous types of IPNs made in bulk and also includes such materials as IPNs based on latexes and suspension-sized particles thermoplastic IPNs, which contain physical cross-links in one or both polymers, and hence may be (partly) soluble and a number of other closely related materials. 

Methods of Blend Preparation. Most polymer pairs are immiscible, and therefore, their blends are not formed spontaneously. Moreover, the phase structure of polymer blends is not equilibrium and depends on the process of their preparation. Five different methods are used for the preparation of polymer blends (60,61) melt mixing, solution blending, latex mixing, partial block or graft copolymerization, and preparation of interpenetrating polymer networks. It should be mentioned that due to high viscosity of polymer melts, one of these methods is required for size reduction of the components (to the order of /ttm), even for miscible blends. 

A third mode of IPN synthesis takes two latexes of linear polymers, mixes and coagulates them, and crosslinks both components simultaneously. The product is called an interpenetrating elastomeric network, lEN. There are, in fact, many different ways that an IPN can be prepared each yields a distinctive topology. 

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