In situ polymerization, of monomers

Bis-maleimide resins composed of BMI and diamines have been reported in the early 1960s in the patent literature. Since that time, a number of patents have appeared describing improvements in their properties and uses [3]. Although many bis-maleimide resins are commercially developed, relatively few reports of their use as adhesives are to be found in scientific journals [4-10]. Improvements of maleimide resins are mirrored in the improvements of thermosetting polyimides. For example, the method of in situ polymerization of monomer reactants (PMR method) was developed [6]. 

Porous polymer materials, especially in particulate form, are of interest in a diverse range of applications, including controlled drug delivery, enzyme immobilization, molecular separation technology, and as hosts for chemical synthesis [101-104]. MS materials have been used as hosts for the template synthesis of nanoporous polymer replicas through in situ polymerization of monomers in the mesopores [105-108]. 

One of the potential ways how to improve CNT dispersion in polymer matrixes is in-situ polymerization of monomers in presence of nanotubes. Monomers have very small shear viscosity in orders of about lO -lO"3 Pa.s, compared to relatively high viscosity of polymer melts, 103-106 Pa.s. This low viscosity helps to better impregnation and wetting of CNT material, which leads to more efficient dispersion and debundling of the nanotubes aggregates, especially when ultrasound is used as a dispersing agent. 

Chemical modification will be defined for this chapter as any chemical reaction between some reactive part of a wood cell wall component and a simple single chemical reagent, with or without catalyst, that forms a covalent bond between the two components. This excludes in situ polymerizations of monomers in the lumen structure of the wood and those reactions that result in cell wall-penetrating polymer systems that do not result in any cell wall attachment. It is well known that lumen-filling polymer treatment results in large improvements in mechanical properties, but these are mainly a result of the properties of the new polymer introduced [ 1 ]. 

Many commercial applications of CPs involve coatings on various substrates and the most important method for processing CPs as coatings is the in situ polymerization of monomers on the surfaces of substrates. It is commonly used to coat fabrics and to fabricate Langmuir-Blodgett films. ... 

Polymer monoliths are prepared by in situ polymerization of monomers such as styrene, acrylate, methacrylate, acrylamide, or cyclic compounds and have been reviewed thoroughly [19]. The selectivity of the monolithic column can be changed by incorporation of functional monomers during the polymerization. A... 

With the recent advancement in the pharmaceutical technology, new and innovative techniques are being employed in the fabrication of polymeric nano/microparticles (Table 57.3). A number of review articles and chapters describing various aspects of particle preparation and characterization have been published in the last few decades. - Hence we are outlining some of the techniques used in the preparation of particles, which are also used for oral peptide delivery. Particles are prepared mainly by two processes. The first process is the in situ polymerization of monomer through suitable polymerization process to yield polymeric particulates. The second process is based on the dispersion of well-characterized preformed polymers of synthetic or natural origin using a suitable technique (Scheme 57.2). 

NASA Lewis Research Center further developed the norbornene project, culminating in the PMR concept, where a class of addition type poiyimides was formed by the in situ Polymerization of Monomer Reactants (PMR) [42]. 

Generally, there are three preparative methods for synthesizing polymer/metal oxide nanocomposites (Fig. 1). The first is direct mixing or blending of a polymer and metal oxide NPs, either as discrete phases (known as melt mixing) or in solution (solution mixing). The second is a sol-gel process, which starts with a molecular precursor at ambient temperature and then forms a metal oxide framework by hydrolysis and condensation. The third is in-situ polymerization of monomers in the presence of metal oxide NPs. 

There are many synthetic approaches for integrating polymers with PSi. Figure 2 summarizes the main methods that are practiced for the fabrication of PSi-polymer composites. In general, these techniques can be divided into two main categories. The first is incorporating a preformed polymer with the Si scaffold. The second involves in situ polymerization of monomers within/on the PSi. Herein, we will focus only on the main techniques for the fabrication of PSi-polymer composites. 

Li B, He JM (2004) Investigation of mechanical property, flame retardancy and thermal degradation of LLDPE-wood-fibre composites. Polym Degrad Stab 83 241-246 Li Y, Liu Z, Dong X, Fu Y, Liu Y (2013) Comparison of decay resistance of wood and wood-pol5mier composite prepared by in-situ polymerization of monomers. Int Biodeter Biodegr 84 401-406... 

In comparison with these conventional methods, in-situ polymerization of monomers in presence of cellulose nanofillers is advantageous in many ways ... 

In situ polymerization of monomers confined in molecule-sized spaces has been used to synthesize stereospecific polymers [62]. In this method, the layered silicate is swollen within the liquid monomer or a monomer solution so that polymer formation can occur between the intercalated sheets. Polymerization can be initiated either by heat or radiation, by the diffusion of a suitable initiator, or by an organic initiator or catalyst fixed through cation exchange inside the interlayer before the swelling step, as shown in Fig. 6. 

Several methods can be applied for the dispersion of silica nanoparticles in polymer matrices. The simplest one is the blending of preformed particles in a polymer matrix. The matrix can be provided either by a preformed polymer or by an in situ polymerization of monomers in a suspension with silica particles [50]. 

The properties of the conducting polymer nanocomposites depend on the their structure determined by the interfacial adhesion between conducting polymers and the secondary component as well as the aspect ratio. Therefore, the synthetic strategies for the preparation of conducting polymer nanocomposites are of great importance. A correct selection of the preparation techniques is critical to obtain nanocomposites with suitable properties. The top-down and bottom-up approaches can also be applied for the synthesis of polymer nanocomposites. Direct mixing of nanofiller into polymer matrix in solution for the preparation of polymer nanocomposites is a top-down approach as shown in Fig. 14, in which layered silicate is mixed with polymer. The in situ polymerization of monomer in the presence nanoparticles previously prepared or the in situ polymerization of monomer in the presence of precursor nanoparticles as shown in Fig. 15 are bottom-up approaches. 

---