Polymerisable macromonomer

The microemulsion polymerization and copolymerization of amphiphilic monomers and macromonomers can produce the fine polymer latex in the absence of emulsifier [98-100], The surface active block or graft copolymer stabilizes the latex particles. The chemically bound emulsifier (surface active copolymer) onto the particles surface is known to be much more efficient emulsifier than the emulsifier physically adsorbed onto the particle surface and, therefore, very stable and fine polymer latexes are formed. The similar behavior is expected with the transferred emulsifier radicals. For example, the surface-functionalized nanoparticles in the 12 - 20 nm diameter range can be prepared by a one-step or two-step microemulsion copolymerisation process of styrene (and/or divinylbenzene (DVB)) with the polymerisable macromonomer (Fig. 7) [93, 101]. 

Novel thermally responsive polymeric nanoparticles that show high colloidal stability were prepared by Laukkanen et al. via emulsion polymerisation of VCL in the presence of the amphiphilic macromonomer cw-methoxy polyethylene oxide undecyl a-methacrylate (MAC11EO42) (Fig. 15) [177,178,182]. The macromonomer itself proved to be highly sur-... 

The size distribution of the PVCL microgel particles synthesised by a batch emulsion polymerisation was monomodal and reasonably narrow [177], regardless of the choice of the emulgator, SDS (El, E2) or macromonomer (E3, E4). The size distributions remain monomodal upon subsequent grafting. A typical size distribution of a PVCL microgel (El) at 20 °C is presented in Fig. 17, as well as the effect of grafting, as a second step, on the hydrodynamic size (El-g). 

The macromonomer route assures uniform distribution of dendrons along the polymer backbone. Acrylates and styrenes with pendant dendrons proved to be well suited for polymerisation [57]. However, steric hindrance between monomers bearing higher-generation dendrons and the spatial requirements of the end of the chain cause problems The monomer reacts with the chain end only in the case of slight, if any, steric hindrance. Thus the method only provides access to dendronised linear polymers with relatively low molar masses... 

Meijs, G.F. and Rizzardo, E. (1990) Reactivity of macromonomers in free-radial polymerisation. JMS-Rev. Macromol. Chem. Phys., C30(3 4), 305-77. 

To illustrate the recently discovered pathways to functional monomers, Meier and colleagues studied the synthesis of a long-chain diester from a (o-hydroxy fatty acid derived from palmitic acid. The idea was to transform the (0-hydroxyl function into a mesylate, followed by an elimination reaction to prepare the (O-unsaturated fatty acid methyl ester (FAME), which was dimerised by a SM coupling to obtain the desired C30 diester (Scheme 5.5) [14]. This macromonomer was then polymerised with diols and diamines to prepare long-chain polyesters and polyamides (PA) with interesting thermal properties, such as a melting temperature (T ) of 109 °C for the polyester and 166 °C for the PA. 

Reversely, poly(e-caprolactone) (PCL) macromonomers capped by a norbomene end-group were synthesised and (co)polymerised by ROMP with the same catalytic system (Scheme 4) [17]. 

DPs of 96 and 127 respectively), complete polymerisation is obtained at monomer to initiator molar ratio of only up to 20 and 10 respectively. Beyond these ratios the ROMP reaction stops before complete consumption of macromonomers and two peaks are observed in the GPC traces. The lower molecular weight peaks have the same retention time as the macromonomer the high molecular weight peaks are due to the product graft copolymer. 

Figure 2. SEC trace obtained for macromonomer with a target degree of polymerisation of 50 EO units.

Journal of Rubber Research 4, No.l, 1st Quarter, 2001, p.28-37 MINIEMULSION POLYMERISATION OF A BIFUNCTIONAL MACROMONOMER... 

Details are given of the miniemulsion polymerisation of a hydrophobic bifunctional ethylene-butylene copolymer macromonomer. Polymerisation kinetics were examined using potassium persulphate and AIBN. Solubihties of the resultant latex film in toluene, chloroform and THE were investigated. 16 refs. 

The dispersion polymerisation of styrene was studied in a mixed ethanol-water medium using 0.1-2 wt% of omega-methoxy poly(ethylene oxide)40 undecyl-alpha-methacrylate macromonomer as a steric stabiliser. The polymerisation rate reached a maximum at a styrene conversion of around 18% and remained almost constant up to about 55% conversion. The molecular weight of the polymer increased with increasing conversion of styrene up to about 55%. The polymerisation rate and activation energies were studied and discussed. Spherical monodisperse particles of around 250 nm diameter were obtained for the final stable latices.The grafted poly(ethylene oxide) macromonomers were enriched and anchored on the surface of PS latex particles with a top surface composition of 28% macromonomer. 33 refs. SINGAPORE Accession no.665916... 

In summary, these results demonstrated that pyrolysis with simultaneous multidetection GC is an effective technique for chain-end analysis of PMMA macromonomers and their prepolymers synthesised via radical polymerisation. In this method, minute amounts of heteroatom-containing end groups in PMMA are determined using the ratios between heteroatom-containing fragments and backbone MMA-related products, which are simultaneously detected by the heteroatom-selective detector and by FID, respectively. An appropriate internal standard is used to correlate the simultaneously observed pyrograms. 

Cordova and co-workers [106] prepared macromonomers using Candida antarctica lipase B as catalyst. Ring opening polymerisation of e-CL was initiated by alcohols which included 9-decenol, cinnamyl alcohol, 2-(4-hydroxyphenyl) ethanol and 2-(3-hydroxyphenyl) ethanol. In another approach acids and esters which included n-decanoic acid, octadecanoic acid, oleic acid, linoleic acid, 2-(3-hydroxyphenyl)acetic acid, 2-(4-hydroxyphenyl)acetic acid and 3-(4-hydroxyphenyl)propanoic acid were added to the prepolymerised e-CL. Consequently, acid terminated PCL was formed. In the first approach 9-decenol-initiated PCL was formed (24 hours, 99% conversion of e-CL) with an average MW of 1,980 Da. In the second approach linoleic acid terminated PCL was formed with an average MW of 2,400 Da (51 hours, 99% conversion). In an effort to simultaneously control both the hydroxyl and carboxyl end groups of macromers, esters, e.g., 9-decenyl oleate, 2-... 

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