Multi-functional monomer

Diphenyl ether Multi Functional Monomer p-Phenoxybenzoyl chloride p-Phenoxyphenoxybenzoyl chloride Terephthaloyl chloride and 1,4-diphenoxybenzene [9]... 

H.J. Spinelli, Acrylic star polymers containing single- and multi-functional monomers in the core, made by group transfer polymerization, US Patent 4 810 756, assigned to E. I. Du Pont De Nemours And Company, March 7,1989. 

The photoinduced addition of a thiol (RSH) to an olefinic double bond has been used to produce polymer networks by taking multi-functional monomers [37-44]. The thiol-ene polymerisation proceeds by a step growth addition mechanism which is propagated by a free radical, chain transfer reaction involving the thiyl radical (RS ). The initial thiyl radicals can be readily generated by UV-irradiation of a thiol in the presence of a radical-type photoinitiator. The overall reaction process can be schematically represented as follows ... 

The photopolymerisation of a mixture of multi-functional monomers or oligomers that polymerise by different mechanisms leads to the build-up of two interpenetrating polymer networks (IPN). An obvious requirement is that the two monomers must be fully compatible, and their polymers as well, in order to avoid segregation... 

These materials are swollen by solvents, but they do not dissolve. They form a gel. The amount of swelling depends on the density of cross-linking. If a difunctional monomer is added to a chain polymerization system, or a tri- or multi-functional monomer is used in step polymerization, then as the polymerization proceeds the probability of the chains coupling together increases and the reaction is characterized by a sudden enormous rise in viscosity. This is the gel point. If the polymerization is allowed to continue, then a thermoset polymer results. 

Owing to multi-functionahty, physical properties such as solubihty and the glass transition temperature and chemical functionahty the hyperbranched (meth) acrylates can be controlled by the chemical modification of the functional groups. The modifications of the chain architecture and chemical structure by SCV(C)P of inimers and functional monomers, which may lead to a facile, one-pot synthesis of novel functionahzed hyperbranched polymers, is another attractive feature of the process. The procedure can be regarded as a convenient approach toward the preparation of the chemically sensitive interfaces. 

In the following years, many imprinted polymers were prepared by two- or multi-step swelling and polymerisation method using mostly EDMA as a crosslinker and various functional monomers interacting with the chosen template... 

A multi-microsensor array of potentiometric MIP chemosensors has been devised for determination of a serotonin neurotransmitter [180]. In the toluene porogenic solvent solution, the MAA functional monomer and the EGDMA cross-linker were polymerized in the presence of the serotonin hydrochloride template (Table 6). Subsequently, the resulting MIPs were immobilized on a plasma polymer layer by swelling and polymerization. Plasma polymerization was performed using styrene or ethylbenzene as the monomer. The chemosensor fabricated that way was appreciably responsive to serotonin while selectivity to serotonin analogues, like acetaminophen... 

A multi-MIP array has been fabricated photolithographic ally for determination of an albuterol broncholidator (Table 6) [185]. 20-pm diameter acrylic MIP beads have been synthesized by co-polymerization of the benzyl methacrylate functional monomer, MAA functional monomer and HEMA cross-linker in the propylene glycol monomethyl ether acetate porogenic solvent. Thermo-radical polymerization on a Pt electrode was initiated by AIBN. Albuterol was recognized in the... 

Monomers Multi-functional initiatorType of star Reference... 

Fossil based raw materials, mainly oil, gas and occasionally coal, are used almost exclusively for the manufacture of monomers. Plant materials, the so-called renewable resources, have been used earlier and could become more significant once again in the future. Although the plastics in these cases are obtained by direct polymerization of their monomers, the synthesis of the monomers themselves often requires several intermediate steps. The multi-functional multiple intermediate compounds in the plastic synthesis steps cannot be clearly defined as monomers in every case. The poly-con-... 

Notably, the Negishi cross-coupling of difunctionalized macrocyclic monomers produced the annelated polyether precursors to polyradicals 54, 55, and 56 in significant isolated yield for each polyether (Fig. 37). This suggested that analogous cross-couplings of multi-functionalized macrocyclic monomers could provide highly cross-linked polymers with fractal dimensionalities beyond one. 

The (co-)polymerization of functional monomers was also explored with the Ni and Pd catalyst systems. The multi-component Ni catalyst (Ni(O2CR)2 -i-HSbFg-i-OBFs LlyO-i-lOAlLlj) works very well for the copolymerization of norbornene and 5-triefhoxysilylnorbornene. The copolymerization of norbornene and with 5-10 mol% 5-triethoxysilylnorbomene monomers yields a high molecular weight copolymer of fhe same molar composition in excellent yield (85%) at a 4000 1 monomer to nickel molar ratio. 

Other in situ gelling polymeric systems under investigation for endovascular embolization inelude multi-functional Michael-type addition monomers that... 

The synthesis of a miktoarm star copolymer of the type AnBn has been also demonstrated. The synthesis was performed via ATRP using divinylbenzene, as the core cross-liking agent. PEO macroinitiator chains were utilized for the polymerization of divinylbenzene forming a star polymer, with a random number of branches. The above star polymer was used as a multi-functional initiator for the polymerization of methacrylate monomers. Therefore, the synthesis of an amphiphilic miktoarm star copolymer was realized [54]. Finally, the hydrolysis of the protected methacrylate block led to the preparation of the desired DHBCs, namely the PEOn-PMAA stars. SEC analysis of the preeursor PEOn-PMMA copolymer revealed a relatively broad molecular weight distribution. Nevertheless, this is a good example for the synthesis of A Bn double hydrophilic star copolymers. 

The extension of these DA-hased polymerizations to multi-functional furan and/or maleimide monomers naturally leads to crosslinked materials, whose original feature is related to the fact that they can be readily decrosslinked by a simple thermal treatment. Since the first report of a mendable material based on this principle, but applied in cycles [69], several similar studies have appeared in the literature [64] including interesting applications in the realm of thermally removable foams [64] and adhesives [64]. It seems likely that such a simple and useful strategy will continue to draw attention for the preparation of novel intelligent materials. 

Thermal or photo-polymerization of multi-functional low molar mass monomer results in a high, densely crosslinked network. Liquid crystallinity of monomers or precursors can be frozen in after in situ polymerization. Interestingly, some monomers are not liquid crystalline themselves however, as the curing reaction proceeds, a nematic phase is developed and finally remained. Photopolymerization is divorced from the thermal properties of the material, while thermal polymerization is limited by the finite temperature range over which the liquid crystal phase can exist. But photopolymerization can be only suitable for thin film sample due to the limitation of the penetrating ability of the light used. 

In the synthesis of these macromolecular system, many parameters involved can affect the information associated with the binding sites, such as functional monomers/polymers, crosslinkers and solvents/porogens. Thus, both the feasibility of imprinting and the proper preparation conditions need exploration for the preparation of efficient imprinted materials (Liu Z. et al., 2010). It is important to state that MIP can be obtained in different formats, depending on the preparation method followed. To date, the most common polymerizations for preparing MIPs involve conventional solution, suspension, precipitation, multi-step swelling and emulsion core-shell. There are also other methods, such as aerosol or surface rearrangement of latex particles, but they are not used routinely (Puoci et al., 2011). 

In the following we will outUne two basic methods to synthesize LC side chain elastomers. As a starting point for the synthesis of LC elastomers a mixture of mesogenic monomers and bi- or multi-functional crossUnker molecules may serve. This will be discussed in the first part of the section. Alternatively, polymer analogous reactions, where the mesogenic moieties are attached to a polymer backbone, can be employed, which will be discussed in the second part of the section. 

---