Poly phthalamide s

The earliest commercially utilized poly(amide) (PA) is silk. Silk is a natural PA. It is produced by the larvae of the silkworm. Spider silk is a natural PA, composed from modest amino acids. It can be regarded as a natural high performance polymer. The first synthetic PAs were produced in the 1930s, now termed as nylons, which are pure aliphatic. On the other side of the product palette of PAs are pure aromatic PAs, which are addressed as aramids. In aramids, both the diacid and the diamine moieties are of an aromatic nature. Whereas nylons are considered as engineering polymers, aramids are classified as high performance polymers. This chapter focuses on partially aromatic PAs, which are settled in between the two extremes. 

From the chemical view, partially aromatic PAs can be regarded as nylons, where the aliphatic moieties are replaced to some extent by aromatic groups. Most commonly, aromatic diacid moieties are introduced, however, there are t) es that additionally use aromatic diamines. 

Partially aromatic PAs are considered as poly(phthalamide)s (PPA)s, when at least 60% of the diacid component is constituted from aromatic acids, prevalently from terephthalic acid (TPA) or isophthalic acid (IPA). PPAs and some t) es of partially aromatic PAs are considered as high performance polymers. 

The idea to substitute aliphatic diacids with aromatic diacids goes back to the mid 1950s. In the literature, PPAs are not always explicitly declared as such, but are rather treated as a group of PAs. For this reason, a literature search using poly(phthalamide) will not cover all relevant entries. 

Before we discuss the monomers that are used in PPAs, it is in order to talk briefly about the nomenclature of these types of polymers. In nylons, there is common nomenclature to identify the types by a number code. The numbers refer to the chain lengths of the diamine and the diacid. In the case of aromatic compounds, for IPA, I is used and for TPA, T is used. In PPA, a similar nomenclature is used. Examples are given in Table 12.1. However, for fully aromatic PAs the nomenclature is not extended for practical use. 

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Poly(phthalamide)s 405 Table 12.6 Antioxidants for Poly(phthalamide)... 

Bohdanecky found that published data on many semi-flexible polymers fit eq 3.5. Figure 5-8 shows this with the data [40] for poly (tere-phthalamide-p-benzohydrazide) (PPAH) in dimethyl sulfoxide (DMSO). The linear relation as observed here permits unequivocal estimation of I and S. If we have one more relation among q, Ml, and d, it becomes possible to determine these three unknowns. Molecular weight dependence data of (5 ) or / may be utilized as such an additional relation. Bohdanecky [39] proposed the use of the relation... 

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