Polycondensations copolymers

Sorta E. and MeUs L.A., Block length distribution in finite polycondensation copolymers. Polymer, 19, 1153, 1978. 

Somewhat more complicated is the Markov chain describing the products of polycondensation with participation of asymmetric monomers. Any of them, AjSaAj, comprises a tail-to-head oriented monomeric unit Sa. It has been demonstrated [55,56] that the description of molecules of polycondensation copolymers can be performed using the Markov chain whose transient states correspond to the oriented units. A transient state of this chain ij corresponds to a monomeric unit at the left and right edge of which the groups A, and A are positioned, respectively. A state ji corresponds here to the same unit but is oriented in the opposite direction. However, a drawback of this Markov chain worthy of mention is the excessive number of its states. 

Poly(phenylquinoxaline—arnide—imides) are thermally stable up to 430°C and are soluble in polar organic solvents (17). Transparent films of these materials exhibit electrical insulating properties. Quinoxaline—imide copolymer films prepared by polycondensation of 6,6 -meth5lene bis(2-methyl-3,l-benzoxazine-4-one) and 3,3, 4,4 -benzophenone tetracarboxyUc dianhydride and 4,4 -oxydianiline exhibit good chemical etching properties (18). The polymers are soluble, but stable only up to 200—300°C. 

The bulk polycondensation of (10) is normally carried out in evacuated, sealed vessels such as glass ampules or stainless steel Parr reactors, at temperatures between 160 and 220°C for 2—12 d (67). Two monomers with different substituents on each can be cocondensed to yield random copolymers. The by-product sdyl ether is readily removed under reduced pressure, and the polymer purified by precipitation from appropriate solvents. Catalysis of the polycondensation of (10) by phenoxide ion in particular, as well as by other species, has been reported to bring about complete polymerisation in 24—48 h at 150°C (68). Catalysis of the polycondensation of phosphoranimines that are similar to (10), but which yield P—O-substituted polymers (1), has also been described and appears promising for the synthesis of (1) with controlled stmctures (69,70). 

Grafting can also occur in the amide nitrogen, either through an anionic-type mechanism which is beheved to operate when ethylene oxide [75-21 -8] and similar copolymers are grafted to polyamides, or through a polycondensation mechanism when secondary amides are formed as graft copolymers (70). 

Interfacial polycondensation between a diacid chloride and hexamethylenediamine in the presence of small amounts of ACPC also yield polymeric azoamid, which is a macroazo initiator.[27] In this manner, azodicarbox-ylate-functional polystyrene [28], macroazonitriles from 4,4 -azobis(4-cyano-n-pentanoyl) with diisocyanate of polyalkylene oxide [29], polymeric azo initiators with pendent azo groups [3] and polybutadiene macroazoinitiator [30] are macroazoinitiators that prepare block and graft copolymers. 

The reaction of ACPC with linear aliphatic amines has been investigated in a number of Ueda s papers [17,35,36]. Thus, ACPC was used for a interfacia] polycondensation with hexamethylene diamine at room temperature [17] yielding poly(amide)s. The polymeric material formed carried one azo group per repeating unit and exhibited a high thermal reactivity. By addition of styrene and methyl methacrylate to the MAI and heating, the respective block copolymers were formed. 

Polycondensation of ACPC with triphenol gave a multibranched MAI with which a star block copolymer could be derived [13]. 

Recently, various polyesters such as poly(ethylene adipate), poly(tetramethylene adipate), poly(caprolac-tone), and poly(aliphatic carbonate), having terminal hydroxyl groups, were reacted with ACPC to give corresponding macroazoesters and their thermal behaviors were observed by DSC [14]. The block copolymers of these polycondensation polymers with addition polymers such as PSt and PMMA were synthesized [14]. 

In addition to a block copolymer, a microcapsule was made from suspension interfacial polycondensation between diacid chloride having aromatic-aliphatic azo group and aliphatic triamine [70,71]. The capsule was covered with a crosslinked structure having an azo group that was thermally stable but sensitive to light so as to be applicable to color photoprinting materials. 

Triarylamines have been employed in arylene vinylene AB copolymers 38 by Horhold et al. using a Homer polycondensation route of aldehydes and ketones 36 with fois-phosphonate 37 (Scheme 1-12) 164]. Phenylamines have remarkably low redox potentials and their charge transport properties have been investigated extensively [65]. EL devices comprising triarylamines have demonstrated low driving voltages. 

See also PBT degradation structure and properties of, 44-46 synthesis of, 106, 191 Polycaprolactam (PCA), 530, 541 Poly(e-caprolactone) (CAPA, PCL), 28, 42, 86. See also PCL degradation OH-terminated, 98-99 Polycaprolactones, 213 Poly(carbo[dimethyl]silane)s, 450, 451 Polycarbonate glycols, 207 Polycarbonate-polysulfone block copolymer, 360 Polycarbonates, 213 chemical structure of, 5 Polycarbosilanes, 450-456 Poly(chlorocarbosilanes), 454 Polycondensations, 57, 100 Poly(l,4-cyclohexylenedimethylene terephthalate) (PCT), 25 Polydimethyl siloxanes, 4 Poly(dioxanone) (PDO), 27 Poly (4,4 -dipheny lpheny lpho sphine oxide) (PAPO), 347 Polydispersity, 57 Polydispersity index, 444 Poly(D-lactic acid) (PDLA), 41 Poly(DL-lactic acid) (PDLLA), 42 Polyester amides, 18 Polyester-based networks, 58-60 Polyester carbonates, 18 Polyester-ether block copolymers, 20 Polyester-ethers, 26... 

Block copolymers containing polysiloxane segments are of great interest as polymeric surfactants and elastomers. Polycondensation and polyaddition reactions of functionally ended prepolymers are usually employed to prepare well-defined block copolymers. The living polystyrene anion reacts with a,co-dichloropoly(dimethyl-siloxane) to form multiblock copolymers398. ... 

Tough, transparent, heat and flame resistant, multiblock (bisphenol fluorenone carbonate) (BPF)-dimethylsiloxane copolymers have been synthesized by interfacial polycondensation of phosgene with various mixtures of BPF end-capped siloxane oligomers and free BPF or its monosodium salt 232). Siloxane content of the copolymers were varied between 7 and 27%. Presence of two Tg s, one below —100 °C and the other as high as 275 °C, showed the formation of two-phase morphologies. 

Poly(unsaturated ester)-siloxane segmented copolymers have been prepared by the polycondensation of epoxy-terminated polydimethylsiloxanes and carboxy-terminated poly(ethylene adipate-co-maleate) oligomers 243). Reactions have been conducted in cellosolve solvent, at 140-150 °C, in the presence of 2% by weight potassium hydroxide catalyst. The molecular weights reported were fairly low. The same group has also prepared poly(hexamethylene adipate)-polydimethylsiloxane copolymers con-... 

Once all the remaining sites have reacted a polystyrene fitted with grafts of known length at approximately constant intervals is obtained. As the backbone arises by polycondensation, fractionation is necessary when samples of low polydispersity are needed. Whether the grafts are distributed regularly or randomly hardly affects the behavior of the graft copolymer 91). 

As the synthetic approach to polydichlorophosphazene put forward by R. De Jaeger has been already described in several recent review articles [10,38,57, 172], in this paper we will illustrate only the polycondensation approach proposed by I. Manners and H. R. Allcock, together with the consequences of this reaction on the preparation of chain phosphazene copolymers (block copolymers) [220,223,224,232-234,240], and star polymers [222]. 

The fact that this polycondensation process takes place at room temperature, with careful control of both molecular weight and molecular weight distribution of the final polymers or copolymers produced are definitive advantages over the corresponding ROP reaction of (NPCl2)3 in molten state. 

Ester-thioester copolymers were enzymatically synthesized (Scheme 7). ° The lipase CA-catalyzed copolymerization of e-caprolactone with 11-mercaptoundecanoic acid or 3-mercaptopropionic acid under reduced pressure produced the polymer with molecular weight higher than 2 x 10". The thioester unit of the resulting polymer was lower than the feed ratio. The transesterification between poly(8-caprolactone) and 11-mercaptoundecanoic acid or 3-mercaptopropionic acid also took place by lipase CA catalyst. Recently, aliphatic polythioesters were synthesized by lipase CA-catalyzed polycondensation of diesters with 1,6-hexanedithiol. ... 

The blend is partially crosslinked with a vinyl monomer when dissolved in an organic aprotic solvent and has a pH of 5.0 or lower. The first block copolymer is prepared by polycondensing a bis-hydroxyalkyl ether, such as dipropylene glycol, diethylene glycol, and the like, with propylene oxide. Next, the resulting propoxylated diol is reacted with ethylene oxide to produce the block copolymer. The second copolymer is prepared by polycondensing 2-amino-2-hydroxymethyl-1,3-propanediol, commonly known as TRIS, with... 

The microheterogeneity coefficient was introduced only for the description of the microstructure of binary copolymers with symmetric units. At increased number of unit types and/or when account is taken of structural isomerism, the role of Km will be performed by other parameters analogous to it. A general strategy for the choice of these latter has been elaborated in detail [12], while their values have been measured via NMR spectroscopic techniques for a variety of polycondensation polymers [13]. 

Alongside the radical distinction of the mechanism of this process from that of chain polymerization, linear polycondensation features a number of specific peculiarities. So, for instance, the theory of copolycondensation does not deal with the problem of the calculation of a copolymer composition which normally coincides with the initial monomer mixture composition. Conversely, unlike chain polymerization, of particular importance for the products of polycondensation processes with the participation of asymmetric monomers is structural isomerism, so that the fractions of the head-to-head and head-to-tail patterns of ar-... 

Lipase CA catalyzed the polymerization of cyclic dicarbonates, cyclobis (hexamethylene carbonate) and cyclobis(diethylene glycol carbonate) to give the corresponding polycarbonates [105]. The enzymatic copolymerization of cyclobis(diethylene glycol carbonate) with DDL produced a random ester-carbonate copolymer. As to enzymatic synthesis of polycarbonates, reported were polycondensations of 1,3-propanediol divinyl dicarbonate with 1,3-propanediol [110], and of diphenyl carbonate with bisphenol-A [111]. 

Weight average molecular weights of poly(HAMCL) with saturated or unsaturated pendent groups are relatively low, compared to Mw s of poly(HASCL), and in the range of 60,000 to 360,000 g mol as depicted in Table 2 [4,30,35,36]. Also for the poly(HAMCL) copolymers, the molecular weight distributions are unimodal. Their polydispersities are in the range of 1.6-2.4, which is narrower than the polydispersity of poly(3HB-co-3HV) copolymers, and close to the theoretical value of 2.0 for synthetic polycondensates such as chemically synthesized polyesters [54]. 

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