Specialty polymer blends

In the plastics industry, specialty polymers are generally considered as high performance, high priced resins whose current market volume is 

The crystalline polymers such as PPS, LCP, PEEK offer the additional advantages of high solvent resistance. Due to the inherently high cost of the specialty polymers, very few blends have been developed for commercial applications. The only driving force for the development of even the few blends of specialty polymers has been the desire to reduce the cost of the base resins by blending with lower cost engineering plastics, although this invariably results in a lower DTUL. Nevertheless, a few commercial blends of specialty polymers exist and their properties will be discussed below  

Polysulfones are aromatic high T, amorphous polymers having a sulfone and an aromatic ether linkage in the recurring units of their backbone. Owing to this structure of their polymer backbones, they display unique resistance to hydrolysis. 

The two commercially significant polysulfones are (a) the polysulfone derived from bisphenol A, which is simply referred to as polysulfone (PSO Udel , Amoco) and (b) the polyethersulfone (PES Victrex , ICI). The current world-wide consumption of all polysulfones is estimated to be less than 19 kton/y about 70% of which belong to the polysulfone (PSO). The hydrolytic stability of polysulfones appears to be their unique advantage over other high heat, transparent thermoplastics 

The primary reasons for developing this blend appear to be (a) to improve the toughness, particularly the notched Izod impact strength 

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

Specialty Polymer Blends and Alloys Along with Trade Names... 

Breuer, O., et al.. Introducing a New Miniature Mixer for Specialty Polymer Blends and Nanoscale Composites, Univ. of Alberta, SPE-ANTEC 2003. 

This overview is an attempt to briefly cover the history and recent developments In environmentally degradable commodity and specialty polymers and plastics. Degradation pathways are mentioned, polymer types, including blends, are reported and the limitations of current testing protocols raised. The chapter concludes with generalizations on structural requirements for degradable polymers. 

In the area of specialty polymers, we are seeing an explosion of new polymer blends, alloys, and composites. The properties of novel polymer alloys, for example, are significantly better than those of the materials from which they are blended, but many aspects of these alloys are not well understood. Most of the materials consist of multiple polymer phases. But there is still uncertainty as to the desired characteristics and size of the polymer domains and the mechanisms by which forces are transferred through the material. All of these questions will benefit from the chemical engineering approach. 

Tinker. AJ. and KP. Jones Blends of Natural Rubber Novel Techniques for Biending with Specialty Polymers, Chapman Hall, New York. NY. 1998. Thomas H. Rogers, Consultant (Rubber and Plastics Industries), formerly Research Manager, Goodyear Tire and Rubber Company. Akron, OH,... 

Among Its many attributes, poly(e-caprolactone) (PCL) Is particularly unique In Its capability to blend with different commercial polymers over a wide composition range. Incorporating FCL segment with other rubbery or glassy blocks will allow us to form novel multiphase block polymers. Such specialty polymers are often used as "oll-ln-oll" type of emulsifiers In polymer blends, whose mechanical properties can be Improved If better homogeneity Is achieved by the emulsifier additives (, ) ... 

Fluoropolymers are notoriously immiscible with any other polymer. Usually, they are dispersed in blends of engineering and specialty polymers either to improve processability or to induce lubricity and abrasion resistance. Examples of the PC/Specialty resin blends are listed in Table 1.68. 

Addition of PPE/PS to POM was used to improve processability, HDT, and mechanical properties [Ishida and Masamoto, 1974]. More recently, POM with a Lewis acid was incorporated into PPE/PA blends to improve compatibilization and induce high heat and impact resistance [Takayanagi et al., 1994]. POM blends with specialty polymers are formulated either to take advantage of POM (the resistance to abrasion), or of the specialty resin e.g., to improve stiffness and wear resistance by incorporation of PEEK or PEI) [Suzuki and Nagahama, 1987]. POM is miscible with polyvinylphenol, PVPh, thus addition of PVPh to blends of POM with COPO compatibilizes the system [Machado, 1993]. 

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