Copoly

One of the mam uses of the linear a olefins prepared by oligomerization of ethylene is in the preparation of linear low density polyethylene Linear low density polyethylene is a copoly mer produced when ethylene is polymerized in the presence of a linear a olefin such as 1 decene [H2C=CH(CH2)7CH3] 1 Decene replaces ethylene at random points in the growing polymer chain Can you deduce how the structure of linear low density polyethylene differs from a linear chain of CH2 units ... 

Figure 7.7 Fj versus fj for styrene (Mi)-methyl methacrylate (M2) copoly mers prepared by the mechanisms indicated. [From D. C. Pepper, Q. Revie London 8 88 (1954).]...

Co3(P04)2 8H20 CO poisoning Copoly(amide-imides) Copolyamides... 

Copoly(amide-imides) comprise an important class of copolyimides that have been developed into a commercial product. Incorporating the amide linkage into the PI makes the polymer more tractable than simple Pis, but involves a loss in thermal stabiUty. However, copoly(amide—imides) still possess quite good thermal stabiUties, intermediate between those of polyamides and Pis (12). They are relatively inexpensive to synthesize. 

A series of cross-linkable copoly(amide—imides) is known to be possible from aromatic diamines and substituted isophthaloyl chlorides containing unsaturated imide rings as a pendent function (13). 

Aromatic copoly(amide—imide)s with Atriazine rings in the repeating unit of the backbone are also possible from a diacyl chloride reacting with preformed imide groups and diamines containing Atriazine rings (15). 

A cross-linked and crystalline copoly(ester—imide) containing an alkene function was made by reaction of an unsaturated diacid chloride containing a cychc imido group with ethylene glycol at low temperature (27). 

Some amorphous copoly(ether—sulfone) fkms have been prepared (117) with Ts around 130°C with no loss in weight up to 400°C in ak or N2. Other backbones iavestigated in this class of polymers are copoly(ether—amides) (118) and copoly(ether—ketones) (119). These polymers show good mechanical properties, flow characteristics, and abrasion resistance. 

Fig. 6. Variation of interface toughne.ss with area den.sity of copolymer for a range of different molecular weight PS-PMMA copoly mens between PMMA and PPO (or PPE) [39J.

A use is for internally illuminated signs in which any color can be introduced. Its dii sional stability recommends it for many optical uses. Acrylics are modified by copoly-mf ition to improve impact strength at the loss their extreme transparency.. An example is aci -modified polyvinyl chloride sheet, which is tougher than aciylonitrile-butadiene-styrene and polycarbonate and is suitable for corrosion-resistant pans, aircraft parts and materia idling equipment. 

Alcohol was then distilled off, until the temperature reached 100°C. 1,706.6 g of distillate was collected. (Theory 1,430 g.) This alcohol was poured into four times its volume of water and an insoluble oil separated (457 g). The insoluble fraction was added back to the copoly-... 

As mentioned in Section II. D., azoperoxy bifunctional initiators play a significant role regarding block copoly-... 

IUPAC recommendations suggest that a copolymer structure, in this case poly(methyl methacrylate-co-styrene) or copoly(methyl methacrylate/slyrene), should be represented as 1. The most substituted carbon of the configurational repeat unit should appear first. This same rule would apply to the copolymer segments shown in Section 7.1. However, as was mentioned in Chapter I, in this book, because of the focus on mechanism, we have adopted the more traditional depiction 2 which follows more readily from the polymerization mechanism. 

TPEs associating both rigid and soft polyester blocks have also been described. They cannot be obtained by the melt polyesterification used for polyesterether TPEs, since interchange reactions would yield random—rather than block — copolyesters. The preferred method involves the reaction of OH-terminated aliphatic and aromatic-aliphatic polyesters with chain extenders such as diisocyanates and results in copoly(ester-ester-urethane)s. 

PAs have also been copolymerized with other polymer systems and, in particular", with polyesters and poly ethers. In the copoly esteramides the crystallinity is decreased by copolymerization, as the crystalline structure of the amide unit is very different from the ester unit. However, alternating polyesteramides behave as homopolymers with a glass ttansition temperature and a melting temperature intermediate to the polyester and the PA polymer (Figs. 3.10 and 3.11).23,24 Polyesters, such as PBT and PET, modified with a small amount of diamide are also copolymers that have a high order.24,73... 

If one wants to modify an existing polyester without losing its high order, copoly-merizing it with diamide units is an option. PBT can be modified with a diamide based on 1,4-butane diamine or p-phenylene diamine and PET with 1,2-ethylene... 

Aliphatic-aromatic copoly imides, 268 Aliphatic-aromatic polyesters, 18, 19 Aliphatic degradable polyesters, 41 Aliphatic diacids, polyamide synthesis from, 183-184... 

Copolyesters, from diacids and diols, 43 Copoly etheramide, 147-148 Copolymerization, wholly aromatic polyesters and, 35. See also Copolymers... 

Chen S., Cao T., and Jin Y., Ruthenium tetraoxide staining technique for transmission electron microscopy of segmented block copoly(ether-ester), Polym. Commun., 28, 314, 1987. 

Applications Open-column chromatography was used for polymer/additive analysis mainly in the 1950-1970 period (cf. Vimalasiri et al. [160]). Examples are the application of CC to styrene-butadiene copoly-mer/(additives, low-MW compounds) [530] and rubbers accelerators, antioxidants) [531]. Column chromatography of nine plasticisers in PVC with various elution solvents has been reported [44], as well as the separation of CHCI3 solvent extracts of PE/(BHT, Santonox R) on an alumina column [532]. Similarly, Santonox R and Ionol CP were easily separated using benzene and Topanol CA and dilaurylthiodipropionate using cyclohexane ethyl acetate (9 1 v/v) [533]. CC on neutral alumina has been used for the separation of antioxidants, accelerators and plasticisers in rubber extracts [534]. Column chromatography of polymer additives has been reviewed [160,375,376]. 

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