Random copolymer of MMA and

There are several examples of random copolymers of methacrylates (R-l to R-3). MMA/nBMA copolymerization was carried out with a copper catalyst, but the products were of low molecular weight because this study was directed to mechanistic studies.263 Random copolymers of MMA and nBMA (R-l) were also obtained in emulsion (MJMn = 1.2—1.3).254 Two monomers were consumed almost simultaneously to give a random or statistical distribution of repeat units along the chains. Copolymerization of MMA... 

STEREOREGULAR BLOCK AND RANDOM COPOLYMERS OF MMA AND ALKYL METHACRYLATE... 

Therefore, the control of stereoregularity of the copolymer may provide another handle for the control of Tg of the copolymer. Figure 6 shows Tg s of stereoregular block and random copolymers of MMA and EMA determined by DSC ... 

Tg value was determined according to ASTM D3418-82. When Tg s of the block and random copolymers of MMA and EMA were determined by the procedure reported by Richardson and Savill Polymer (1975) 16 753), the difference between Tg s of the block and random copolymers became smaller (Suzuki H, private communication). 

Copolymerizations of an equimolar mixture of MMA and MA (R-10) or nBA (R-11) with the nickel catalysts led to simultaneous consumption of the two monomers and gave their random copolymers with controlled molecular weights and relatively narrow MWDs (MwIMn 1.5).135 The copper-catalyzed systems also induced controlled random copolymerizations of MMA and nBA in organic solvents and in emulsion (MJMn 1.2).254-267 However, methacrylate/ acrylate copolymerization may result in gradient structures rather than random structures (section III.F). 

In order to interpret the resulting data, a model is developed for copolymers obtained by SEC fractionation, taking into account the fractionation conditions and specifically the number of fractions. The model predicts the composition and the ratio D(x) of the SEC fraction. D(x) is the ratio between the number-average and the weight-average molar mass, and x is the fraction number. The predictions of the model are compared with SEC-NMR and SEC-MALDI data for the random copolymer of styrene and MMA reacted at high conversion. 

As described above, an ESR study of the reaction of the poly(NMAAm) radical with a MMA/St (MS) or CHMA/St (CS) mixture led to the conclusion that St is incorporated into the poly(NMAAm) microspheres in preference to the methacrylate monomers, to react with the polymer radical. To confirm this conclusion, block copolymers were prepared by the reaction of poly(NMAAm) radicals with MS or CS mixtures, and the relative contents of methacrylate and St in the resulting polymers were determined. The poly(NMAAm) radical was allowed to react with monomer mixtures of different relative concentration for 15 h at 40 °C. The resulting polymer was fractionated into three parts (i.e., AcOEt-soluble, MeOH-soluble and insoluble parts). The AcOEt-soluble part consisted of random copolymer of methacrylate and St, while the MeOH-soluble part consisted of homopoly(NMAAm) and block copolymer. The solvent-insoluble part was block copolymer. The results obtained are summarized in Table 7. 

To summarize, it can be stated that both free radical copolymerization and ATRP can be applied successfully to synthesize random copolymers of MMA with sfMA. First copolymerization experiments with ARGET-ATRP in BFMB as well as in SCCO2 according to Schreiber et al. [70] showed the applicability of the method further optimization is necessary. 

Several s -copolymers of MMA and alkyl methacrylates with narrow MWD were also prepared with -C4HgLi-(n-C4Hg)3Al. Glass transition temperatures for the sL-copolymers of MMA and butyl methacrylate (n-BuMA) are shown in Figure 6. Recently, block and random s -copolymers of MMA and benzyl methacrylate as well as s -poly(benzyl methacrylate) prepared with -C4HgLi-R3Al were found to form stereocomplex with i -PMMA in solid and in solution [16]. 

In this review, synthesis of block copolymer brushes will be Hmited to the grafting-from method. Hussemann and coworkers [35] were one of the first groups to report copolymer brushes. They prepared the brushes on siUcate substrates using surface-initiated TEMPO-mediated radical polymerization. However, the copolymer brushes were not diblock copolymer brushes in a strict definition. The first block was PS, while the second block was a 1 1 random copolymer of styrene/MMA. Another early report was that of Maty-jaszewski and coworkers [36] who reported the synthesis of poly(styrene-h-ferf-butyl acrylate) brushes by atom transfer radical polymerization (ATRP). 

These copolymers will be coded CMIMx, where x indicates the mol% of cyclohexylmaleimide (CMI) units in the copolymer. Prepared by radical polymerisation of MMA and maleimide, the copolymers have a random distribution of the maleimide units. 

Prepared by radical polymerisation of MMA and maleimide, the copolymers have a random distribution of the maleimide units. 

Random copolymerization of MMA with other polar monomers proceeds in a living fashion with relative monomer reactivity ratios in the order BuA > MMA = EtMA > /-PrMA when mediated by 4(Sm Me)/THF [60, 89]. Block polymerization of MMA with other polar monomers as lactone yields ideal living copolymers (PDI = 1.11-1.34) under these conditions. Similarly, ABA triblock copolymers were obtained by sequential addition of MMA, BuA, and MMA [89]. AB block copolymers could be obtained by sequential addition of (L,L)-lactide and (D,D)-lactide (PDI = 1.38) as well as -caprolactone and (l,l)- lactide monomers (PDI = 1.36) in the presence of Y(OCH2CH2NMe2) [82]. 

Hawker et al. [95] and Fukuda et al. [96] both reported on the copolymerization of St with various monomers in 1996. Hawker reported copolymerizations with nBA, MMA, and p-chloromethylstyrene (CMSt), while Fukuda focused on several acrylates, 9-vinylcarbazole, and acrylonitrile (AN), and succeeded in preparing block-random copolymers of St with AN (details below). Neither group found the polymerizations to be well-controlled when low concentrations of St were present in the comonomer feed. However, since then, NMP has been used extensively to prepare copolymers. Pozzo et aL copolymerized St with 4-vinyl pyridine (VP), initiated by benzoyl peroxide (BPO) and using TEMPO as the radical mediator [97]. After purification, the copolymer was reacted with spiro [fluorenecyclopropene] to prepare photochromic copolymers with controlled molecular weights (Scheme 6). 

To extend the )plications of LC-NMR, we have further examined the compositions and blockiness of various polymer mixtures, including pBA and polybutadiene, where 1,4-butadiene, 1,2-butadiene and BA were identified by their unique H chemical shifts at tqrproximately 5.35, 4.95 and 3.98 ppm, respectively. In reverse-phase HPLC with the same solvent gradient conditions as above, homopolymer pBA and polybutadiene eluted at 21.76 and 34.20 min., respectively. TTie random copolymers of p(MMA/BA) and p(MMA/Sty) both eluted between 8 and 18 minutes. Owing to their hydrophobicity, the hi er the percentage of BA and styrene in the copolymer, the longer the retention time. Figure 5 illustrates the LC separation of pMMA, pBA, p(MMA/BA) and p(BA-b-MMA) by a reverse-phase column. A comparison of p(MMA/BA) random copolymer (retention time 13.9 min.) to p(BA-b-MMA) block copolymer (retention time 18.3 min.) with similar composition shows that the block copolymer interacted more with the C-18 stationary phase and eluted at a later time. This result demonstrated that the retention of p(MMA/BA) copolymer by reverse-phase LC is predominately influenced by die pBA portion of dre copolymer. The block copolymer, which mimics the homopolymer pBA, is mote hydrophobic and retained more on die C18 colunm than the random copolymer. The excellent LC separation permits us to quantitatively determine... 

Copolymer sanq)le MB41 is a high conversion (100%) random copolymer of methyl methacrylate (MMA) and butyl acrylate (BA) produced by radical initiation. The san le was injected into the SEC apparatus, and about 40 fractions were collected. Several SEC fractions were then subjected to off-line MALDI and NMR analysis, respectively. 

Random and Gradient Type The spacing between the grafting sites in the polyinitiator backbone can be systematically varied by the incorporation of a noninitiating comonomer into a backbone. For example, TMS-HEMA as a precursor of an ATRP initiator has been copolymerized with MMA [94, 96, 114, 115). The reactivity ratios of MMA and TMS-HEMA are close to unity, which generally leads to random copolymers. However, when these random copolymers were applied as the main chains, CPBs with a random distribution of side chains along the... 

Epoxies can be modified to have low energy surfaces so that they can function in conjunction with silicone-release coatings. For this application, three types of block copolymers (53), each of which consisted of two blocks, were used as surface modifiers. One bloek was a random copolymer of methyl methacrylate (MMA) and 2,3-epoxypropyl methacrylate (GMA), the other was a polymer of lH,lH,2H,2H-heptadecafluorodeeyl acrylate (PFA) which has the following structure. 

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