Interpenetrating polymer network properties

Hamcerencu, M., Desbrieres, J., Popa, M. and Riess, G. R. (2009). Stimuh-sensitive xanthan derivatives/N-isopropylacrylamide hydrogels influence of cross-hnk-ing agent on interpenetrating polymer network properties. Biomacromolecules, 10,1911-1922. 

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). 

IPNs are found in many applications though this is not always recognised. For example conventional crosslinked polyester resins, where the polyester is unsaturated and crosslinks are formed by copolymerisation with styrene, is a material which falls within the definition of an interpenetrating polymer network. Experimental polymers for use as surface coatings have also been prepared from IPNs, such as epoxy-urethane-acrylic networks, and have been found to have promising properties. 

The ultimate goal of bulk modification endows with the polymer-specific surface composition or a specific property for a given application. The bulk modification can be classified into blending, copolymerization, interpenetrating polymer networks (IPNs), etc. 

Frisch, H. L. Du, Y. Schultz, M. Interpenetrating Polymer Network (IPN) Materials. In Polymer Networks. Principles of Their Formation Structure and Properties-, Stepto, R. F. T., Ed. Blackie Academic London, 1998 pp 186-214. 

Materials known as interpenetrating polymer networks, IPN s, contain two or more polymers, each in network form (6 9), A practical restriction requires that at least one of the polymer networks has been formed (i.e. polymerized or crosslinked) in the immediate presence of the other. Two major types of synthesis have been explored, both yielding distinguishable materials with different morphologies and physical properties. 

This is a theoretical study on the entanglement architecture and mechanical properties of an ideal two-component interpenetrating polymer network (IPN) composed of flexible chains (Fig. la). In this system molecular interaction between different polymer species is accomplished by the simultaneous or sequential polymerization of the polymeric precursors [1 ]. Chains which are thermodynamically incompatible are permanently interlocked in a composite network due to the presence of chemical crosslinks. The network structure is thus reinforced by chain entanglements trapped between permanent junctions [2,3]. It is evident that, entanglements between identical chains lie further apart in an IPN than in a one-component network (Fig. lb) and entanglements associating heterogeneous polymers are formed in between homopolymer junctions. In the present study the density of the various interchain associations in the composite network is evaluated as a function of the properties of the pure network components. This information is used to estimate the equilibrium rubber elasticity modulus of the IPN. 

Since the start of modern interpenetrating polymer network (IPN) research in the late sixties, the features of their two-phased morphologies, such as the size, shape, and dual phase continuity have been a central subject. Research in the 1970 s focused on the effect of chemical and physical properties on the morphology, as well as the development of new synthetic techniques. More recently, studies on the detailed processes of domain formation with the aid of new neutron scattering techniques and phase diagram concepts has attracted much attention. The best evidence points to the development first of domains via a nucleation and growth mechanism, followed by a modified spinodal decomposition mechanism. This paper will review recent morphological studies on IPN s and related materials. 

Polyurethane-acrylic coatings with interpenetrating polymer networks (IPNs) were synthesized from a two-component polyurethane (PU) and an unsaturated urethane-modified acrylic copolymer. The two-component PU was prepared from hydroxyethylacrylate-butylmethacrylate copolymer with or without reacting with c-caprolactonc and cured with an aliphatic polyisocyanate. The unsaturated acrylic copolymer was made from the same hydroxy-functional acrylic copolymer modified with isocyanatoethyl methacrylate. IPNs were prepared simultaneously from the two-polymer systems at various ratios. The IPNs were characterized by their mechanical properties and glass transition temperatures. 

Polymer blends and interpenetrating polymer networks (IPNs) are different from copolymers but like copolymers are used to bring together the properties of different polymers [Paul et al., 1988]. The total of all polymer blends (produced by both step and chain reactions) is estimated at about 3% of the total polymer production—about 3 billion pounds per year in the United States. There is considerable activity in this area since new products can be obtained and markets expanded by the physical mixing together of existing products. No new polymer need be synthesized. 

Huang G-S, Li Q, Jiang L-X (2002) Structure and damping properties of polydimethylsiloxane and polymethacrylate sequential interpenetrating polymer networks. J Appl Poly Sci 85(3) 545-551... 

HeXW et al. (1992) Poly(dimethylsiloxane)/poly(methyl methacrylate) interpenetrating polymer networks. 2. Synthesis and properties. Polymer 33(4) 866—871... 

Gilmer TC et al. (1996) Synthesis, characterization, and mechanical properties of PMMA/poly(aromatic/aliphatic siloxane) semi-interpenetrating polymer networks. J Poly Sci Part A Poly Chem 34(6) 1025—1037... 

Polysiloxane Based Interpenetrating Polymer Networks synthesis and Properties... 

Abstract This article summarizes a large amount of work carried out in our laboratory on polysiloxane based Interpenetrating Polymer Networks (IPNs). First, a polydimethylsiloxane (PDMS) network has been combined with a cellulose acetate butyrate (CAB) network in order to improve its mechanical properties. Second, a PDMS network was combined with a fluorinated polymer network. Thanks to a perfect control of the respective rates of formation of each network it has been possible to avoid polymer phase separation during the IPN synthesis. Physicochemical analyses of these materials led to classify them as true IPNs according to Sperling s definition. In addition, synergy of the mechanical properties, on the one hand, and of the surface properties, on the other hand, was displayed. 

For many investigators in the sound and vibration damping field, interpenetrating polymer networks, or IPNs, are a new class of polymers capable of exhibiting relatively broad-band damping properties. The purpose of this chapter is to provide an introduction (1,2) to these materials, what they are, how they are made, the kind of morphologies that may be expected, and why they have the properties they have. 

This brief introduction to the synthesis and general properties of interpenetrating polymer networks demonstrates that IPNs are complex multicomponent polymer... 

These compounds have the structure of an interpenetrating polymer network (IPN) of phenolic resin with materials having elastomeric properties. (3-8) Except for early work by Aylsworth in 1914, there has been no work on full IPN phenolic materials. 

In our laboratory, much attention has been devoted to the investigation of in situ sequential polyurethane/poly(methyl methacrylate) interpenetrating polymer networks (SEQ PUR/PAc IPNs) (2- ) in which the elastomeric polyurethane network is completely formed in the presence of the methacrylic monomers before the onset of the radical copolymerization which leads to the second network. To each polymerization process corresponds a typical kinetics, which however is not completely independent from each other ( -8). The results obtained with such SEQ IPNs show that the properties do in... 

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

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