Polystyrene microspheres with polyglycidol (polyGL) in a surface layer were synthesized in batch radical emulsifier-free
emulsion copolymerizations of styrene and surfmers, α-t-butoxy-ω-vinylbenzyl-polyGL macromonomers (VB-polyGL). Macromonomers
with number-average molecular weight Mˉn=950 (VB-polyGL950) and Mˉn=2700 (VB-polyGL2700) were used for these polymerizations. In all syntheses the initial concentrations of styrene and initiator
(K2S2O8) were constant. The initial macromonomer-to-styrene ratios were varied from 1.10 × 10−3 to 1.64 × 10−2 mol/mol and from 3.46 × 10−4 to 3.47 × 10−3 mol/mol for VB-polyGL950 and VB-polyGL2700, respectively. The diameters of microspheres obtained were smaller for the syntheses
with higher concentrations of macromonomers. Syntheses with VB-polyGL950 yielded microspheres with number-average diameters
(Dˉn) from 216 to 900 nm and with a bimodal diameter distribution. The number-average diameters of microspheres obtained with
VB-polyGL2700 varied from 220 to 650 nm, depending on the initial concentration of macromonomer. Their diameter distributions
were monomodal, with a diameter polydispersity parameter (ratio of weight-average and number-average diameters) in the range
1.007≤Dˉw/Dˉn≤1.022. For each type of microsphere the fraction of polyGL in a surface layer and the surface concentration of sulfate anions
were determined. The fraction of polyGL in the surface layer was related to the initial monomer composition in the polymerizing
mixture. Adsorption of human serum albumin onto surfaces of some poly(styrene/VB-polyGL) microspheres was up to 10 times lower
than for the polystyrene microspheres obtained in a similar emulsifier-free emulsion polymerization of styrene.
Received: 26 September 2000/Accepted: 19 February 2001 相似文献
The monodispersed polymeric particles with an unusual structure were prepared by the dispersion copolymerization of acrylonitrile/styrene(AN/St) in mixed solvents of ethanol/water by using the poly(N-isopropylacrylamide) (PNIPAAm) macromonomer as a reaction stabilizer. It was found that the AN monomer plays a key role in the formation of the particles with special morphology analyzed via scanning electron microscopy (SEM). The reaction parameters have remarkable influences on the particle size and morphology. The particles possess a thermosensitive property according to the result of laser light scattering(LLS). 相似文献
Star formation : A novel and easy method is reported for the synthesis of well‐defined star polymers with high star yield by applying conventional radical copolymerization of linear macromonomer and divinyl cross‐linkers in a homogeneous solution (see figure).
The synthesis of thiol‐functionalized long‐chain highly branched polymers (LCHBPs) has been accomplished in combination of ring‐opening metathesis polymerization (ROMP) and thiol‐Michael addition click reaction. A monotelechelic polymer with a terminal acrylate and many pendent thiol groups is first prepared through adding an internal cis‐olefin terminating agent to the reaction mixture immediately after the completion of the living ROMP, and then utilized as an ABn‐type macromonomer in subsequent thiol‐ene reaction between acrylate and thiol, yielding LCHBPs as the reaction time prolonged. Au nanoparticles are then covalently conjugated onto the surface of thiol‐functionalized LCHBP to fabricate novel hybrid nanostructures, which is shown as one interesting application of such functionalized metathesis polymers. This facile approach can be extended toward the fabrication of novel nanomaterials with sophisticated structures and tunable multifunctionalities.