Poly macromer

The study of acid-base interaction is an important branch of interfacial science. These interactions are widely exploited in several practical applications such as adhesion and adsorption processes. Most of the current studies in this area are based on calorimetric studies or wetting measurements or peel test measurements. While these studies have been instrumental in the understanding of these interfacial interactions, to a certain extent the interpretation of the results of these studies has been largely empirical. The recent advances in the theory and experiments of contact mechanics could be potentially employed to better understand and measure the molecular level acid-base interactions. One of the following two experimental procedures could be utilized (1) Polymers with different levels of acidic and basic chemical constitution can be coated on to elastomeric caps, as described in Section 4.2.1, and the adhesion between these layers can be measured using the JKR technique and Eqs. 11 or 30 as appropriate. For example, poly(p-amino styrene) and poly(p-hydroxy carbonyl styrene) can be coated on to PDMS-ox, and be used as acidic and basic surfaces, respectively, to study the acid-base interactions. (2) Another approach is to graft acidic or basic macromers onto a weakly crosslinked polyisoprene or polybutadiene elastomeric networks, and use these elastomeric networks in the JKR studies as described in Section 4.2.1. 

A photoreactive macromer consisting of the reaction product of poly(capro-lactone-co-lactide) and pentaerythritol ethoxylate was prepared by Chudzik et al. (3) and used as tissue implants. 

Poly(vinyl alcohol) was tosylated in anhydrous pyridine at 85°C and then reacted with dithiothreitol potassium thioacetate and stirred overnight. The mixture was then reacted with dithiothreitol at ambient temperature to form poly(vinyl alcohol)-g-dithiothreitol. It was hydrolyzed by methanolysis and the thiol macromer isolated. 2... 

The cyclic tin alkoxides have the additional advantage of offering a convenient synthetic pathway for the synthesis of macromers, triblock, and multiblock copolymers [81,82]. Macromers from l-LA [83],e-CL [84], and l,5-dioxepan-2-one (DXO) [85] have been synthesized as well as triblock poly(L-LA-b-DXO-b-L-LA) [86] and multiblock copoly(ether-ester) from poly(THF) and e-CL [87]. The polymerization proceeds by ring expansion and the cyclic structure is preserved until the polymerization is quenched by precipitation. 

It should be noted that the inconsistency in the flammability performance of various types of poly-mer/POSS hybrid systems could be ascribed to several factors, such as, the type of polymeric material, the structure of POSS macromer, and the degree of dispersion of POSS in the polymer matrix. 

Another early attempt to prepare low molecular weight co-unsaturated polymers (the terms Macromer 1 and macromonomer were not used until 1978 6y) was made by Greber et al. 8) by means of anionic deactivation. A living m-carbanionic poly-... 

Poly(e-caprolactone) and Poly(ethylene Glycol) Macromer. 62... 

Poly( ethylene glycol)-co-poly(lactone) Diacrylate Macromers and... 

Poly( -caprolactone)/poly(ethylene Glycol) Macromer... 

With 2-methylpropene as M, both linear and star macromers have been prepared [92-94]. Many kinds of inifers may, of course, be used. For example Kress and Heitz prepared macromers from poly(oxytetramethylene) chains with acrylate or methacrylate end groups, by THF polymerization initiated by superacids with anhydrides as co-initiators - transfer agents [95]. 

An elegant alternative to living polymerization for the preparation of block polymers is to use functionalized Grignard initiators. The polymerization of methyl methacrylate to isotactic (in toluene at — 78"C) or syndiotactic polymers (in THF at — llO C) can be initiated by o-, m-, and p-vinylbenzylmagnesium chloride. The polymers had a low polydispersity and contained one vinylbenzyl group at the chain end, by H-NMR. The poly(methylmethacrylate) macromers thus obtained were polymerized or copolymerized with styrene to give graft and block polymers of controlled architecture [50,51]. 

Kim, I.S. Jeong, Y.I. Kim, S.H. Self-assembled hydrogel nanoparticles composed of dextran and poly(ethylene glycol) macromer. Int. J. Pharm. 2000, 205, 109-116. 

Macromers by Controlled Initiation. New and unique graft copolymers can be prepared by copolymerizing macromers (macromolec-ular monomers) with conventional monomers. The synthesis of poly(butyl acrylate- -isobutylene), i.e., the first graft synthesis that involves carbocationic controlled initiation, has recently been accomplished by the following route (9) ... 

More details of the Inoue experiments are as follows the poly (amino acid) macromer was synthesized in THF by reacting -benzyl-L-glutamate (BLG) — NCA with N-methyl-N-(4-vinylphen-ethyD-ethylenediamine. 

MW of 120,000 daltons) [61]. In fact the nonreactive NAD presented before (structures 6.15 and 6.16) are poly ethers with extended molecular weight, the chain extender being the epoxy resins or the diisocyanates (or polyisocyanates). As in the case of macromers, it is possible to obtain high, solid stable polymeric dispersions, of low viscosities, with nonreactive NAD too. 

Sawhney and co-workers prepared a series of PEC-co-poly(a-hydroxy acid) diacrylate macromers and investigated their photopolymerization into crosslinked bioerodible hydrogels. Certain types of these hydrogels were evaluated for use in preventing postsurgical adhesion and vascular restenosis. ... 

Sawhney, A. S., Pathlak, C. P. and Hubbel, J. A., Bioerodible hydrogels based on photo-polymerized PEG-co-poly(x-hydroxy acid) diacrylate macromers. Macromolecules, 26, 581, 1993. 

Donini et al. reported the preparation of poly(methacrylic add-g-polyethylene glycol) nanospheres by solntion or precipitation polymerization. The free radical polymerization of methacryUc acid with PEG macromer was carried out using a photoinitiator in water. Pluronics-based polymers were used to prevent the aggregation of these nanospheres and to render than redispersion ability. 

A.S. Sawhney, C.P. Pathak, J.A. Hubbell, Bioerodible hydrogels based on photopolymerized poly(ethylene glycol)-co-poly(.alpha.-hydroxy acid) diacrylate macromers. Macromolecules 26 (1993) 581-587, doi 10.1021/ma00056a005. 

Sawhney, A.S., Pathak, C.P., and Hubell, J.A., 1993, Bioerodible Hydrogels Based on Photopolymerized Poly(ethylene glycol)-co-poIy(a-hydroxy acid) Diacrylate Macromers. Macromolecules, 26 581... 

Bryant, S. J., Davis-Arehart, K. A., Luo, N., Shoemaker, R. K., Arthur, J. A. Anseth, K. S. (2004) Synthesis and characterization of photopolymerized multifunctional hydrogels water-soluble poly(vinyl alcohol) and chondroitin sulfate macromers for chondroc5te encapsulation. Macromolecules, 37, 6726-6733. 

He, S., Timmer, M. D., Yaszemski, M. J., Yasko, A. W., Engel, P. S. Mikos, A. G. (2001) Synthesis of biodegradable poly(propylene fumarate) networks with poly(propylene fumarate)-diacrylate macromers as crosslinking agents and characterization of their degradation products. Polymer, 42, 1251-1260. 

Shin, H., Temenoff, J. S. Mikos, A. G. (2003) In vitro cytotoxicity of unsaturated oligo[poly(ethylene glycol) fumarate] macromers and their cross-linked hydrogels. 

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