Acrylates, fluorinated side chains

Macromolecules have also been specifically designed and synthesized for use as emulsifiers for lipophilic materials and as stabilizers in the colloidal dispersion of lipophilic, hydrocarbon polymers in C02. We have demonstrated the amphiphilicity of fluorinated acrylate homopolymers, such as PFOA, which contain a lipophilic, acrylate like backbone and C02-philic, fluorinated side chains (see Fig. 3) [103]. It has been demonstrated that a homopolymer which physically adsorbs to the surface of a polymer colloid prevents agglomeration by the presence of loops and tails (see Fig. 4) [113]. The synthesis of this type of... 

Among all remaining monomers, those containing (per)fluorinated side chains such as fluorinated acrylates, vinyl ethers or esters, maleimides and styrenic monomers are also very interesting and have been studied in (co)telo-merisation. Most of them have been previously reviewed [15]. However, they are not mentioned in this chapter. 

Poly(acrylates) and (alkyl acrylates). - Structured nanopore films of poly(styrene-block-methyl methacrylate) copolymers have been made with controlled spectral sensitivity, such that each block is sensitive to a specific degradation wavelength. In copolymers of 2,2,2-trifluoroethyl methacrylate with vinyl ethers, the photosensitivity is controlled by the vinyl ether units. Photodegradation occurs at the tertiary positions of the ether units followed by lactone formation and chain scission processes. Furthermore, the fluorinated side chains have been found to inhibit cyclization reactions. 

W.C. Wang, R.H. Vora, E.T. Kang, K.G. Neoh, C.K. Ong, L.F. Chen, Nanoporous ultra-low-K films prepared from fluorinated polyimide with grafted poly(acrylic acid) side chains, Adv. Mater. 16 (1) (2004) 54-57. 

Wang W-C, Vora R H, Kang E-T, Neoh K-G, Ong C-K, Chen L-F (2004) Nanoporous Ultra-low-K Films Prepared from Fluorinated Polyimide with Grafted Poly(acrylic acid) Side Chains. Adv. Mater. 16 54-57. 

In this work we have demonstrated that a new class of heavily fluorinated acrylic and methacrylic resins can be efficiently synthesized and then cured to solid form with radical initiator at elevated temperatures. These cured resins were found to have low dielectric constants, which are close to the minimum known values for Teflon and Teflon AF. In contrast to tetrafluoroethylene, our monomers are processable owing to the fact that they are liquids or low-melting solids, and moreover are soluble in common organic solvents. Lower dielectric constants are obtained as fluorine contents on the polymer backbone or side chain increase, when acrylate is replaced by methacrylate, when ether linkages are present in the fluorocarbon, and when aromatic structure is symmetrically meta-substituted. 

Water-repellent rat skin surfaces were also obtained with fluorinated acrylates or methacrylates whereas polar groups in the side chain im-... 

As a result of the their -CF3 terminated side groups and comb-like structure, the typical range of surface energies for fluorinated acrylic polymers (5.6-7.S mN/m) are even lower than that of PTFE ( 20 mN/m) [35]. The p(PFDA) side chains with eight perfluorinated carbons, so-called C8, provide highly desirable iCVD surface properties but there is concern over the bioaccumulation factor of the monomer [36], suggesting that future research would benefit from utilizing monomers with shorter perfluorocarbon side chains. 

PS-fc-PI diblock copolymers [65], poly(fumarate)s or poly(acrylate)s [131], lamellar structures are found in nearly all cases if the number of m is not too small. The backbone and its flexibility seem to have only marginal influence. In simple terms, the strong phase separation into areas with fluorinated segments and areas with the nonfluorinated rest seems to be the first principle in structure formation. Whereas in sf alkanes besides lamellar structures also hexagonally packed cylinder structures are possible [128], the attachment of the. segments as side chain onto the polymer backbone prevents structure modifications with other symmetries. 

Miscellaneous Polymers With Grafted Peifluorinated Side Chains Following the high solubility of fluorinated poly((meth)acrylates), the grafting of long perfluorinated chains has been applied to a variety of C02-phobic polymers including poly(styrene), poly(para-phenylenes), polysiloxanes, and polyphosphazenes to enhance their solubility in SC-CO2. 

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