Reinforcement structure, mechanical flexibility

The application of polymer systems with an alternative curing mechanism gives the opportunity to shape concrete and the textile reinforcement in only one step. Furthermore a non-economic way of curing can be avoided and one separate process-step - the curing of the prepreg - can be canceled. ISF and ITA are developing a coated and flexible prepreg reinforcement structure for FRC. Thus, flat and poly-shaped structural FRC parts could be realized. 

Haque A, Shamsuzzoha M, Hussain F, Dean D (2003) S2-glass/Epoxy polymer nanocomposites Manufacturing structures, thermal and mechanical properties, J Compos Mofer 37 1821-1837. Joubaud L, Achim V, Trochu F (2005) Numerical simulation of resin infusion and reinforcement consolidation under flexible cover, Polym Compos 26 417-427,... 

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. 

The conclusion was reached that the mechanical properties of glass-reinforced unsaturated polyester are influenced by the chemical structure of the spacer groups in the methacrylate functional silane. Effective factors include hydro-phobicity, reactivity of the double bond, chain flexibility of the backbone, and adsorption behavior. 

Adhesive joints in reinforced plastics structures are capable of achieving higher strength than mechanical ones and may be preferred for that reason, but once made, adhesive joints cannot be disconnected and they can be vulnerable to prolonged high humidity. Their durability depends more on the flexibility and toughness of the resin used in the adhesive than on its strength [39]. 

The second point relates to the exceptional mechanical and fatigue strengths of fibers compared to the small quantity of used material. Both flexible and rigid fibrous structures are then able to reinforce faulty organs while withstanding repeated and endless stress environments such as blood pressure cyclic increase. 

The discovery of carbon nanostructured materials has inspired a range of potential applications. More specifically, the use of carbon nanotubes in polymer composites has attracted wide attention. Carbon nanotubes have a unique atomic structure, a very high aspect ratio, and extraordinary mechanical properties (strength and flexibility), making them ideal reinforcing compounds. Moreover, carbon nanotubes are susceptible to chemical functionalization, which broaden their applicability. For instance, surface functionalization of carbon nanotubes is an attractive route for increasing their compatibility with polymers in composites, also improving the dispersability in raw materials and the wettability. 

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