Poly crosslinked shell

By templating and crosslinking, tubuli with an electroactive interior were generated [166, 325]. These tubuli are still electrochemically active in organic solvent, although the interior polyferrocenylsilane is shielded by a rather thin poly (dialkylsiloxane) shell (Fig. 32). 

Whilst organic polymer seeds are quite readily encapsulated by a PDMS shell (due to surface tension issues), PDMS cores need to be crosslinked and the organic polymer layer made hydrophilic by charged monomers such as (meth)acrylic acid, in order safely to achieve the expected core-shell structure. The grafting of styrene/ acrylonitrile (St/AN) onto a poly(butadiene) shell led to a striking change in the structure of the particles, from core-shell to a flocculated, moon-like configuration. 

Tomalia et al. reported that the surface amines of PAM AM dendrimer can successfully react with methyl esters of other PAMAM dendrimers to afford core-shell tecto-(dendrimer) molecules [65]. Furthermore, they also reported the synthesis of rod-shaped cylindrical dendronized polymers from poly(ethyleneimine) cores without any crosslinking, albeit with the use of excess reagents [58]. These reports lead us to propose a new approach toward hybridized dendrimers and polymers (path C, Figure 15.3). As shown in Scheme 12,... 

Other nutshell materials have been synthesised [164]. Hydrophobic latex particles containing a crosslinked poly(VBC) core and a macroporous poly(styrene/DVB) shell were prepared from concentrated o/w emulsions. Similarly, hydrophilic porous particles of crosslinked acrylamide surrounding a linear poly(ethyleneoxide) core were formed from w/o HIPEs. The poly(VBC) cores of the hydrophobic particles were quaternised and used to bind [Co(CO)4] anions, whereas the hydrophilic latexes were employed in the immobilisation of lipase. 

ASA structural latexes have been synthesized in a two stage seeded emulsion polymerization. In the first stage, partially crosslinked poly(n-butyl acrylate) and poly( -butyl acrylate-sfaf-2-ethylhexyl acrylate) rubber cores are synthesized. In the second stage, a hard styrene acrylonitrile copolymer (SAN) shell is grafted onto the rubber seeds (16). 

Core-shell polymers were commercially introduced as impact modifiers for poly(vinyl chloride) PVC, in the 1960s. They are produced by a two-stage latex emulsion polymerization technique (Cruz-Ramos, 2000). The core is a graftable elastomeric material, usually crosslinked, that is insoluble in the thermoset precursors. Typical elastomers used for these purposes are crosslinked poly(butadiene), random copolymers of styrene and butadiene,... 

Recently, core-shell type microgels, which contain a hydrophobic core and a hydrophilic thermosensitive shell, have become attractive for scientists because such systems can combine the properties characteristic of both the core and the shell [53], We have prepared core-shell microgel particles consisting of a poly(styrene) core onto which a shell of polyCA-isopropylacrylamide) (PS-PNIPA) has been affixed in a seeded emulsion polymerization [54-56], In this case, the ends of the crosslinked PNIPA chains are fixed to a solid core, which defines a solid boundary of the network. In this respect, these core-shell latex particles present crosslinked polymer brushes on defined spherical surfaces. The solvent quality can be changed from good solvent conditions at room temperature to poor solvent conditions at a temperature... 

Related thermo-sensitive, cross-linked polymer vesicles were also formed by self-assembly of poly(2-cinnamoylethyl methacrylate)-W< cfc-poly((V-isopropylacry-lamide) (PCEMA61 — fc—PNIPAM22) copolymer and subsequent photo-crosslinking of the PCEMA shells [228]. The vesicles can load a large amount of 4-aminopyridine (Apy) and release the compound at a tunable rate depending on temperature. 

MBS with controlled size of the elastomeric particles transparent Copolymer of vinylchloride, alkyl acrylate, and vinyhdene chloride Butadiene-styrene-methylacrylate-ethylacrylate Core-shell crosslinked ABS with grafted onto it PMMA shell PB-grafted with MM A, styrene and vinyl acetate Poly(butadiene-co-butyl acrylate-co-styrene)... 

IPN crosslinked PBA, crosslinked uncrosslinked SAN Poly(p-hydroxy styrene), PVPh and EVAl Acrylic core-shell copolymer and either PBT or PET Poly(allyl methacrylate-co-butyl acrylate-co-butanediol dimethacrylate-co-styrene-co-methyl methacrylate) or poly (aery lonitrile-co-butyl aery late-co-tricy clodeceny 1 aery late-co- styrene) Poly(acrylate-V-cyclohexyl maleimide), PMI, and a copolymer PMMA — core, crosslinked butyl acrylate-styrene copolymer — middle layer, and PMMA shell d = 200-300 nm PEG/atactic PMMA blends were characterized by PVT at T = 20-200°C and P = 0-200 MPa. Free volume fraction was calculated from an equation of state... 

Another interesting three-component LIPN consists of crosslinked polyorganosiloxane (tet-raethoxysilane as crosslinker) as the first stage, swollen by butyl acrylate monomer (allyl methacrylate as crosslinker) and then polymerized to form the second component, and finally, poly(methyl methacrylate) was grafted onto the IPN core as the shell layer [Isao et al, 1992], Such kind of LIPNs are found to be a good impact modifiers in thermoplastics i.e., they are toughened by the addition of finely divided low phase. 

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