Poly -graft-PMMA

Kim et al. (66) used poly(3-hexylthiophene) (P3HT)-graft-PMMA as a compatibilizer to prepare MWCNT-PMMA composites by solution blending. The CNT content was varied from 0.01 to 0.1 wt%. The resulting composites showed improved tensile strength and modulus. 

Poly(methylmethacrylate), PMMA, latex particles have also served as a model colloidal system for many years (mainly as hard spheres with hydroxy stearic acid (HSA) chains being the grafting choice [91,113,114]). Tunability was achieved by varying the core size and the size of the corona chains. The comparison between chemically grafted (stable) and end-adsorbed temperature-sensitive chains (usually surfactants) has shown that the adsorbed chain particles exhibit similar rheological behavior with chemically grafted particles [115]. 

Surfactants have also been used to overcome the solubility limitation of synthetic polymers in CO2 (most common synthetic polymers would be considered to be C02-phobic). For example, surfactants have been used to aid in the dispersion polymerization of poly(methylmethacrylate) (PMMA) in CO2 (58-60). The surfactants used in the polymerizations of PMMA are more accurately referred to as stabilizers. The C02-phobic region acts as anchor to the growing polymer, either by physical adsorption or by chemical grafting. The C02-philic region sterically stabilizes the growing polymer particles, preventing flocculation and precipitation. When a biopolymer is not soluble in CO2, specific surfactants may be designed to aid in the solubilization of the polymer into CO2. 

CH2-CH-OH) -(CH2-CH(OCOCH3)-OH)y-(CH2-CH-OH) -. Block copolymers of ethylene oxide-propylene oxide (ABA block of PEO-PPO-PEO), Pluronics (BASF), Synperonic PE (ICI), H-(0-CH2-CH2) -(CH2-CH (CH3)-0) ,-(CH2-CH2-0) -H. Graft copolymers, for example a poly(methyhnethacrylate) (PMMA) backbone (with some polymethacryhc add) with grafted PEO chains (Atlox4913, Hypermer CG6 ICI). 

ABS-type resins are used as impact modifiers for PVC, but the resultant blend has insufficient transparency for application in clear bottles. Transparency can be obtained by grafting PMMA onto crosslinked PBD (5) or poly (butyl acrylate) (6) which has been previously grafted onto PS (Diagram 4). In this case the PMMA branch is compatible with PVC by virtue of its solubility parameter, and optical clarity results from suitable component ratios in the graft copolymer so that the refractive index matches that of PVC. The desired results are not obtained if a copolymer of methyl methacrylate and styrene is... 

An impact resistant PVC-acrylic polymer alloy is formed by grafting PMMA onto poly (ethylhexyl acrylate) (PEHA) and then blending the resultant mixture of graft copolymer and homopolymers with PVC (7) (Diagram 5). 

Sl-ATRP has also been used to modify the surface of quantum dots in order to improve the dispersibility and stability of these nanoparticles. Farmer and Patten demonstrated the use of Sl-ATRP to graft PMMA from CdS/Si02 core-shell nanoparticles [201]. A film formed from the resulting grafted nanoparticles exhibited the same luminescence properties as the CdS core, with the inorganic cores uniformly distributed throughout the polymer matrix. Esteves et al. reported grafting of poly(n-butyl acrylate) from CdS quantum dots via miniemulsion ATRP [202]. Characterization of the nanocomposites demonstrated an even dispersion of CdS cores in the polymer matrix. 

Figure 22 offers another example of the interfacial gradient, specifically showing that the volume fraction of chemically end-grafted polystyrene chains varies as a function of distance from a surface for its blends with different matrix polymers. Polybutadiene (PBD) and poly(methyhnethacrylate) (PMMA) are immiscible with polystyrene (PS) in the bulk PS is chemically identical with the grafted chains, while poly(vinyl methylether) (PVME) and a blend of polyCphenylene oxide) and PS (PPO/PS) are miscible with polystyrene in the bulk. The chemically grafted material concentrates at the surface and does not extend any further than 350 A into the bulk. 

These thiohydroxamic esters have seen use in grafting of PAN onto PE,iM of PS, PAM and I MPAM onto cellulose127128 and of PS, PMMA, PVP and PAM onto poly(arylene ether sulfone).12 7 The process involves derivitization of a parent carboxy functional polymer to form the thiohydoxamic ester 82 (R=polvmcr) which then behaves as a polymeric transfer agent and/or radical generator. 

In the standard nomenclature [poly(MA)-gra/r-poly(MR)] the first named monomer(s) form the backbone while those named second are the grafts or arms. Thus, PMMA-gra//-PS indicates a backbone of PMMA and grafts of PS. 

A radical initiator based on the oxidation adduct of an alkyl-9-BBN (47) has been utilized to produce poly(methylmethacrylate) (48) (Fig. 31) from methylmethacrylate monomer by a living anionic polymerization route that does not require the mediation of a metal catalyst. The relatively broad molecular weight distribution (PDI = (MJM ) 2.5) compared with those in living anionic polymerization cases was attributed to the slow initiation of the polymerization.69 A similar radical polymerization route aided by 47 was utilized in the synthesis of functionalized syndiotactic polystyrene (PS) polymers by the copolymerization of styrene.70 The borane groups in the functionalized syndiotactic polystyrenes were transformed into free-radical initiators for the in situ free-radical graft polymerization to prepare s-PS-g-PMMA graft copolymers. 

Poly vinyl chloride v Graft(copolymer) PS/PMMA Poly (phenyl siloxane)... 

Concerning the synthesis of graft copolymers, Jedlinski et al. have prepared poly(MMA-g-(3BL) copolymers via anionic grafting of 3BL from a modified PMMA backbone [85]. PMMA chains were partially saponified by potassium hydroxide and complexed by 18C6 crown ether so as to act as multifunctional mac-... 

During the last 5 years, there have been several reports of multiblock copolymer brushes by the grafting-from method. The most common substrates are gold and silicon oxide layers but there have been reports of diblock brush formation on clay surfaces [37] and silicon-hydride surfaces [38]. Most of the newer reports have utilized ATRP [34,38-43] but there have been a couple of reports that utilized anionic polymerization [44, 45]. Zhao and co-workers [21,22] have used a combination of ATRP and nitroxide-mediated polymerization to prepare mixed poly(methyl methacrylate) (PMMA)Zpolystyrene (PS) brushes from a difunctional initiator. These Y-shaped brushes could be considered block copolymers that are surface immobilized at the block junction. 

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