Introduction to polymer blends

Polymer blends constitute ca. 36 wt% of the total polymer consumption, and their pertinence 

Blending also benefits the manufacturer by offering (i) Improved processability, product uniformity, and scrap reduction, (ii) Quick formulation changes, (iii) Plant flexibility and high productivity, (iv) Reduction of the number of grades that need to be manufactured and stored, (v) Inherent recyclability, etc. 

The topic is extensively treated in Chapters 4 and 5, thus only the key features are mentioned below. Recently published books and reviews also provide extensive information on the topic [Kotliar, 1981 Porter et al., 1989 Porter and Wang, 1992 Brown, 1992 Ajji and Utracki, 1996 Datta andLohse, 1996 Utracki, 1998a]. 

It is noteworthy that in the absence of the configurational entropy effects (see Chapter 2), the miscibility of polymer blends depends on the balance of small enthalpic and non-configurational entropic effects. Sensitivity of this balance to small variation of the macromolecular structure is illustrated in the series of papers on miscibility of model polyolefins — e.g., see [Rabeony et al., 

Another example is provided by the photoisomerization initiated, reversible phase separation of PVME blends with stilbene-substituted PS [Ohta et al, 1998]. 

Polymer A substance composed of large molecules, the macromolecules, built by covalently joining at least 50 molecular mers, segments, or recurring constitutional repeating units, CRU. Commercial polymers may contain up to 2 wt% of another polymeric modifier 

Copolymer Polymeric material synthesized from more than a single monomer 

Engineering polymer (EP) Processable polymeric material, capable of being formed to precise and stable dimensions, exhibiting high performance at the continuous use temperature CTU 100 °C and having tensile strength in excess of 40 MPa 

Polymer blend (PB) Mixture of at least two macromolecular substances, polymers or copolymers, in which the ingredient contents is above 2 wt%. 

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L.A. Utracky, "Introduction to polymer blends," in L.A. Utracky, ed., Polymer Blends Handbook, Vol. 1, chapter l,pp. 1-122. Kluwer Academic Publishers, Dordrecht, 2002. 

Table 1.52. PP/PEST blends Introduction to Polymer Blends 61... 

Table 1.61. PA specialty polymer blends Introduction to Polymer Blends 69... 

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