Reinforcement of incompatible

These effects have been found by Creton et al. [79] who laminated sheets of incompatible polymers, PMMA and PPO, and studied the adhesion using a double cantilever beam test to evaluate fracture toughness Fc. For the original laminate Fc was only 2 J/m, but when interface reinforced with increasing amounts of a symmetrical P.M.M.A.-P.S. diblock copolymer of high degree of polymerisation (A > A e), the fracture toughness increased to around 170 J/m, and then fell to a steady value of 70 J/m (Fig. 9). 

This behavior can be expected from systems in which entropic factors can be neglected. ABS/PMMA blend plasticized with a mixtme of ethylene and propylene carbonates is an example of system where entropic factors play a role. PMMA is plasticized in polymer electrolytes to increase ionic conductivity. Addition of a plasticizer in an amount sufficient to achieve required conductivity decreases the mechanical performance of the gel to the level that it needs to be reinforced. ABS is added as reinforcing polymer and sufficient mechanical properties are obtained. Two phases are obtained plasticizer-reach phase giving pathway for ion transportation and ABS-rich phase which acts as a matrix increasing mechanical performance. ABS is miscible with PMMA forming transparent blends if no plasticizer is added. Addition of the plasticizer results in phase separation (opaque materials) because of incompatibility between ABS and the plasticizer. This is an example of a system in which the plasticizer is not uniformly distributed among participating polymers but the plasticizer is found in the PMMA-rich phase. ... 

Landfilling carpet waste, as well as many other thermoplastic wastes, is not sustainable. A key issue is whether post-consumer carpet (PCC) should be separated into its primary thermoplastic base polymers or used as a mixture. A composite with a matrix based on a mixture of incompatible polymers is a way of upgrading the polymer mix and is potentially inexpensive. If the reinforcing fibers dominate the composite properties, then having a matrix comprised of incompatible polymers can be tolerated. The results presented here indicate composites with attractive properties can be made using a matrix of mixed incompatible polymers. 

During the processing of reinforced composites, incompatibility between the reinforcements and the matrix materials can cause a variety of problems, due to the different chemical properties of the constituents, which results in very poor adhesion between them. A possible solution is the chemical modification of both the reinforcements and the matrix. A strong interfacial interaction is required for adequate load transfer. Strong adhesion between the phase and the reinforcements results in a poor phase-matrix relationship, because the phase border plays a key role in determining the properties of the composite. The efficiency of the load transfer between the reinforcement and the matrix is affected not only by molecules on the phase board, but also by other properties, such as thickness. 

Induction of phospholipase or LAH activity has already been shown in a number of plant-pathogen systems, notably during the incompatible interactions of bean leaves with bacteria, and of potato tubers with Phytophhtora infestans [8, 9]. Besides initiating the lipoxygenase pathway, these enzymes are supposed to play diverse roles In relation to defence. They might provoke extended membrane damage in the microbial partner on the one hand, and display acyl transferase activity related to reinforcement of the cuticular barrier, on the other hand [10]. 

One of the ways to prepare a blend of incompatible polymer pair in which the dispersed phase forms in-situ reinforced fibres is an utilisation of extrasion line equipped with converging die. The whole extrasion line used in this study consisted of a Brabender measuring single-screw extrader with 30/25 D, a Zenith PEP II gear pump with 1.2 cm /rev and a flat extrasion die with 2x20 mm outlet cross-section. The polymer melt passing through die was firstly... 

Indeed, the multi-layered model, applied to fiber reinforced composites, presented a basic inconsistency, as it appeared in previous publications17). This was its incompatibility with the assumption that the boundary layer, constituting the mesophase between inclusions and matrix, should extent to a thickness well defined by thermodynamic measurements, yielding jumps in the heat capacity values at the glass-transition temperature region of the composites. By leaving this layer in the first models to extent freely and tend, in an asymptotic manner, to its limiting value of Em, it was allowed to the mesophase layer to extend several times further, than the peel anticipated from thermodynamic measurements, fact which does not happen in its new versions. 

The main hurdle for the use of starch as a reinforcing phase is its hydrophillicity leading to incompatibility with polymer matrix and poor dispersion causing phase separation. Two strategies have been adopted to improve the performance of polysaccharides. 

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. 

It appears (Table 11) that the reinforcing ability exhibited by a HAF carbon black in polybutadiene or EPR is much lower after its surface has been previously modified by grafting of polystyrene M). Such results cannot, however, be associated with the elastomer s incompatibility towards the polystyrene grafts since poly-isoprene-grafted carbon blacks yield similar conclusions 65). 

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