Poly processing characteristics

A number of thermally stable polymers have been synthesized, but in general the types of structures that impart thermal resistance also result in poor processing characteristics. Attempts to overcome this problem have largely been concentrated on the incorporation of flexible groups into the backbone or the attachment of stable pendent groups. Among the class of polymers claimed to be thermally stable only a few have achieved technological importance, some of which are polyamides, polyimides, polyquinoxalines, poly quinolines, and polybenzimidazoles. Of these, polyimides have been the most widely explored. 

The economic importance of poly(ester-imide)s led and leads to the developments of new compositions having superior properties and better processing characteristics. Information on these developments can be found in patents and are presented at congresses. It is believed that similar big efforts were made by companies to reduce their costs and to improve the manufacturing processes of poly(es-ter-imide)s. The information on this progress is unfortunately not published. 

The remainder of this paper will be confined to the properties,processing characteristics, and applications of the poly-ethersulphones (PKS) of which there are already four different grades available each with significantly different properties. Unless otherwise stated all the data subsequently presented refers to the standard grade of PES (30OP). 

PS has a low heat distortion temperatnre (HDT) and poly(2,6-dimethyl phenylene oxide) (PPO) has low processability. Blending PS with PPO leads to improved HDT and economy and processing characteristics [17-19]. Applications include appliance housings, automotive dashboards, pump components and television components. PS and polymethyl methacrylate (PMMA) form immiscible blends that exhibit a pearlescent appearance and are used for decorative applications [20]. 

Acrylate polymers are often used in many applications that require good optical properties. However, they are unsuitable for use in the automotive industry because of their brittle characteristics. Thus, when natural rubber is blended with poly(methyl methacrylate), there is a big improvement in the elasticity of the brittle acrylate polymers. It is of interest that thermoplastic natural rubbers are relatively new products in the rubber industry and are fastgrowing items in the polymer market. The acrylate polymers blended with natural rubber can improve various properties of both the natural rubber and the acrylate polymers such as elasticity, adhesion, processability properties, and transparency. These materials are known for their excellent processability, characteristic of acrylate polymers, and their elasticity property provided by natural rubber, thus they exhibit the typical properties of elastomeric materials and can be processed with thermoplastic processing equipment used to prepare acrylate polymers. Many of their interesting properties have been widely developed for several industrial applications such as in the automotive industry, household appliances, medical devices, electrical cables, and headphone cables. ... 

Glass reinforced injection moldable PET (poly(ethylene terephthalate)) resins have become a major engineering thermoplastic. Discovery of injection moldable PETs will be discussed with particular emphasis on crystallization. General processing characteristics and... 

This research note focuses on process characteristics of pol5nner solutions, such as viscosity and electrical conductivity, as well as the parameters of electrospinning using poly-3-hydroxybutyrate modified by titanium dioxide nanoparticles, which have been optimized. The structure of materials has been examined by means of X-ray diffraction, differential scanning calorimetry, IR-spectroscopy, and physical-mechanical testing. 

Fibers. Poly(vinyl alcohol) fibers possess excellent strength characteristics and provide a pleasant feel in fabrics. The fiber is usually spun by a wet process employing a concentrated aqueous solution of sodium sulfate as the coagulating bath. Water insolubiUty, even in boiling water, can be obtained by combining stretching, heat treatment, and acetalization with formaldehyde. Super hydrolyzed PVA is the preferred material for fiber production. 

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