Macromers monomer

Macroinitiators 56 Macromers see Macromonomers Macromolecular monomers 157 Macromolecules, at-co difunctional 151 Macromonomers 21-23, 54-56, 155. 157... 

It can be arranged that these oligomers contain a reactive end group, e.g., hydroxyl, carboxyl, allowing subsequently further polymerisation with a different reactant monomer to take place. These reactive oligomers are called macromers. 

Finally, some polymerisations can be directed such that the final oligomer or polymer contains two or more reactive end groups capable of extended polymerisation with different monomers. These materials are named telechelic macromers or telechelic polymers. 

Thermoset polymers (sometimes called network polymers) can be formed from either monomers or low MW macromers that have a functionality of three or more (only one of the reagents requires this), or a pre-formed polymer by extensive crosslinking (also called curing or vulcanisation this latter term is only applied when sulfur is the vulcanising or crosslinking agent.) The crosslinks involve the formation of chemical bonds — covalent (e.g., carbon-carbon bonds) or ionic bonds. 

Polymers containing one reactive end group are often referred to as macromolecular monomers or macromers. They can be represented as... 

MACROMER (10) is a trademark by CPC International of a new family of monomers. Because they are synthesized via anionic chemistry, their molecular weight is controlled by the ratio of monomer to initiator and they also have very narrow molecular weight distributions. The typical polymeric portions of MACROMEHf that have been investigated are polystyrene, polydiene, and blocks of the two (5, lCi). Some of the typical MACROMER functional groups that were examined are shown in Figure 8. These are shown to indicate the wide variety of functional groups that are useful for various polymerization mechanisms (4). 

There are some problems associated with the synthesis of MACROMERS when the styryl anion is reacted with certain functional monomers such as ... 

It was demonstrated that MACROMER will copolymerize with conventional monomers in a predictable manner as determined by the relative reactivity ratios. The copolymer equation ... 

Functionally terminal polymers are valuable material intermediates. The di- and polyfunctional varieties (telechelic polymers) have found theoretical (e.g., model network) and commercial (e.g., liquid rubber) applications (1, ). On the other hand, macromolecules with a functional group at one chain end (semitelechelic polymers) have been used to prepare novel macromolecular monomers (Macromers ), as well as block and graft copolymers ( -8). 

Acrylic Macromers. Thus far we have shown applications of SFC to the characterizations of monomers and crosslinkers. The next couple applications will focus upon the analysis of oligomeric methacrylates, specifically methacrylate macromers. Methacrylate macromers are frequently used as building blocks for larger architecturally designed polymers. Unfortunately, macromers far exceed the capability of GC and do not possess a chromophore for HPLC analysis. Hatada et. al. has used packed column SFC to analyzed the stereoisomers of oligomeric methylmethacrylate (MMA) prepared by anionic polymerization (13). 

As previously discussed, K IDS does not always provide accurate quantitative data. Therefore, SFC was performed on the macromer. The monomer volatility is not a problem in these studies. Figure 5 is chromatogram of the MMA macromer. The first large broad peak is due to monomer. Identification was based upon retention time comparison to a standard. Each of the corresponding peaks are due to the oligomers up to the 15-mer. We attribute the minor distribution to (VIII). 

The synthesis of novel initiators and the ROP of existing or new monomers and macromers substituted with functional groups provide a very interesting and promising strategy for producing structurally advanced macromolecules. 

The preparation of prepolymers [111] or macromers with functional end groups, so called telechelic polymers, is another approach to structurally unconventional architecture. The functional end groups are introduced either by functional initiation or end-capping of living polymers, or by a combination of the two. In this way, monomers that are not able to copolymerize can be incorporated in a copolymer. Telechelic prepolymers can be linked together using chain extenders such as diisocyanates [112]. In this process, it is essential that the structure and end groups of the prepolymers can be quantitatively and qualitatively controlled [113]. 

Materials. All monomers used for synthesis were free of inhibitors and freshly distilled 2-hydroxyethyl methacrylate (HEMA) dimethyl-acrylamide (DMA) N-vinylpyrrolidone (NPV) methylmethacrylate (MMA) 2-ethylhexylacrylate (EHA) isopropylmethacrylate (IPMA) n-butyl-acrylate (BA) ethyleneglycol-dimethacrylate (EGDMA) dimethacrylate macromer obtained by reaction of 1 mol polytetramethylene oxide diol (MW 2000) with 2 mol 2,4,4-trimethyl-l,6-diisocyanatohexane and 2 mol HEMA (PX). ... 

The scope of MACROMER has been extended to generally designate the end-reactive oligomers of various monomers. A variety of MACROMERS have been reported. Hydroxy end-reactive oligomers were esterified with methacroyl chloride to yield methacrylate end-reactive MACROMERS 41,43) ... 

So far, not many systems are known to meet the conditions of the growth mechanism with activated monomer. Polymerizations of oxirane, chlo-romethyloxirane [145, 146] and of lactams [147] belong to this class. The existence of an electroneutral propagating macromolecule and of an activated monomer results in reduced probability of back-biting reactions and in easier preparation of macromers [145] by means of exchange reactions. 

Transfer reactions are utilized to regulate molecular mass of polymerizing macromolecules, for grafting, and to introduce functional groups into the chains of polymeric monomers , the macromers. 

By reactions (82)-(84), 8 wt. % Br was introduced into the oligomers, an average of 1.95 Br atoms per chain. This work was extended by Kennedy and Smith [91] who selected the co-initiator from a group of transfer agents, which thus had a double function. This new technique they called the inifer method (from co-initiator-trans/er agent). When the rate of transfer to monomer is much less than to the inifer, the formation of the reactive macromer end groups can be better controlled. Macromer formation can be represented by the scheme... 

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) ... 

Ollgoslloxane monomers and macromers are abbreviated as Sn, Mn (n-1,2,5,8, and n>average number of silicon atoms In the macromer). Fluorosubstltuted analogues of S2 were synthesized similarly and abbreviated as FS2, FF2, ans SF2 as shown In the scheme. 

Preparation and Characterization of Polysiloxane Macromers and Oligoslloxane Monomers... 

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