Poly imide addition type

In 1951, Flory reported the condensation reaction of diacid chlorides, e.g. with potassium salts of imides, e.g. the condensation of sebacyl chloride with potassium phthalimide. In this way, A -acyl diimides are formed. Flory pointed out the possibility of forming polymers, when components with higher functionality are used. Poly(imide)s (PI)s from pyromeUitic acid were reported in 1955 by Edwards and Maxwell at DuPont. Tbe diamines used were of aliphatic nature. Later, in addition, aromatic diamines were used. The two major types of Pis are ... 

Long et al. [87] have studied the association of PS-polymers bearing adenine- and thymine endgroups, prepared via Michael-type addition. The association was followed by H-NMR spectroscopy, relying on the temperature dependency of the imide-protons and revealed strong effects in solution. The formation of 1 1 complexes was proven and extended to other polymers such as poly(acrylates) and their respective melt viscosities [88]. Similar results have been reported for PS-b-Pl [89] and polyisoprenes [90]. hi... 

Foaming of PAI will result in heat-resistant foams. There are such foams made from other types of polymers. Advantages and drawbacks of typical high heat-resistant foams are compared in Table 14.2. PI resin foams are regarded as one of the most applicable materials by virtue of their excellent heat stability and flame retardancy. Research has been targeted to improve the physical properties and to simplify the process of preparation. On the other hand, PAI resins exhibit a better heat resistance than poly(ether imide) resins. In addition, they can be more easily processed in the melt. 

These poly(amide-imide) materials were extensively studied in the 1980s in various aspects (e.g. synthesis and preparation of blends with other polymeric materials), [2, 88-96] demonstrating the increasing interest in these materials. More recently, water soluble polyamides and poly(amide-imide)s [97] as well as polyhydroxyimides [98] structurally analogous to those described in Fig. 4.18 have been reported. Additionally, photoactive polymers were prepared by the condensation of a maleopimaric adduct with azo-dye type diamines [99]. The levopimaric... 

This is to be expected since head-to-tail addition of repeat units in amidoethene polymerizations is more common than head-to-head addition (12). Analytical data for carboxyl and imide content for a series of poly(l-amidoethylene)-derived copolymers is contained in Table VII along with rheological test data for aqueous solutions of these samples. The same types of data are given in Table VIII for a series of copolymers derived from po1y(1-amido-1-me thyle thylene). 

Polyanhydride structures can be modified by the addition of aminoacids, linked via imide bonds at the amino terminus, so that the carboxylic acid terminus remains available for the interaction with acetic anhydride [459]. These poly(anhydride-imides) degrade in a similar way as the simple polyanhydride polymers. Other modifications that can take place are copolymers linked with esters. In that way, the polymer contains two types of hydrolytically cleavable bonds. In the presence of water, both types of bonds are hydrolyzed, releasing the dicarboxylic acid and the ester [460]. An example of a poly(anhydride-ester) with application in the medicinal field includes sebacic acid and salicylic acid, a therapeutically useful compound. The release of sebacic acid in the body opens up a variety of potential applications. 

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