Homologous Polymer Blends

Homologous Polymer Blends A subclass of polymer blends limited to mixtures of chemically identical polymers differing in molecular mass. 

Since the homologous polymer blends are known to be miscible It Is not surprising that mixtures of HDR with HDR or IDK with U>BE are miscible as well (12, 13). However, due to the diversity of polymerization methods and the variety of resulting molecular characteristics LLDra/LLDra systems are not always miscible (10, 14-15). In our laboratory three series of blends were prepared by Identical procedure of mixing the same LLDPE with two other LLDPE resins and with LDPE. The zero-shear viscosity vs. composition dependence, n vs. W2, of these systems Is presented In Fig. 1. Only the LLDPE s prepared with the same Tl-catalyst were found to be miscible (curve 2). Neither blend of LLDPE with LDPE (curve 3) nor LLDPE prepared with a vanadium catalyst LLDPE (curve 1) were miscible. There are Indications In the literature (8) that... 

The n vs. n dependence is often used while discussing the dynamic data of polymer blends. Since for simple liquids the plot has the form of a semi-circular arc, deviation from a semi-circle is sometimes Identified with Immlsclbillty. However, as frequently demonstrated for homopolymers (16) and homologous polymer blends ( ) the form of the n" vs. n plot is determined by the shape of the relaxation spectrum the molecular polydlsperslty can modify the Cole-Cole plot as much as the presence of the Interphase. As a rule, the presence of (unsubtracted) yield stress appears in the plot as a sudden departure from a semi-circular pattern at higher n level. 

Polymer blend (PB) Homologous polymer blend Miscible polymer blend... 

Polymer blends, homologous see Homologous polymer blends Polymer blends, terminology 12... 

Homologous polymer blend Mixture of two homologous polymers (usually a mixture of narrow molecular weight distribution fractions of the same polymer)... 

This type of blend is a mixture of two or more fractions of the same polymer, each of which has a different molar mass distribution. Any polydispersed polymer is a homologous polymer blend. These blends are miscible because of the closeness of molar mass distribution. 

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