摘要:

Polymer-polymer blends are the most exciting and promising area for generating novel materials with improved properties in relatively short development times [11. Among different types of blends one can distinguish two important categories. The first category involves homogeneous polymer alloys, which exhibit properties intermediate between those of the individual components following a simple monotonic function that depends on the ratio of the two polymers in the blend. The other category involves heterogeneous polymer blends, wherein one polymer (Polymer A) is dispersed within the other polymer, a continuous phase (Polymer B, Fig. 1) and they are immiscible. This type of blend has an important potential advantage in that it provides the additivity of the phase properties along with new features derived from a unique and particular morphology. For such engineered properties, the dispersed phase should be evenly dispersed in finely divided domains throughout the continuous phase. Such properties are generally achieved by suitable modifiers, which can interlink the phases as depicted in Fig. 2 [2].

ISSN:1532-1797    

DOI:10.1080/15321799608009646

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The production of the polymer materials possessing a good combination of high resistance to mechanical and heat destruction with good processability and low cost is an important problem of polymer chemistry. The continual expansion of the total volume of the output of the thermally resistant polymers shows a considerable increase of their usage in industry [1, 2]. The rise of the maximal temperature of the long-duration operation of polymers from 125°C when using phenol-formaldehyde resins to 315°C when using polybenzimidazoles [3, 4] is accompanied by an increase in the cost of such thermally resistant polymers. For example, the cost of some special polymers having, e.g., high thermal resistance or semiconductor properties is 1000 times the cost of such construction polymers as polyolefines, polyesters, polyurethanes, epoxy resins, etc., because processing of these special polymers requires application of new expensive technologies [3]. Because of this, such modification of the construction polymers that not only improves their properties but also gives them some new attributes, e.g., high thermal resistance or improved optical or electrical properties, is one of the important ways to produce new unique polymers. This modification can be achieved by the following changes in the polymer matrix structure:

ISSN:1532-1797    

DOI:10.1080/15321799608009647

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Polyolefins are a very important class of commercial polymers in the world today and are used in a wide range of applications. Despite their versatility, they suffer from certain drawbacks that exert a limiting influence on their range of applications. They are nonpolar and therefore exhibit poor hygroscopicity, printability, and dyeability. In addition, they have poor dispersibility with inorganic fillers like talc and mica in composites and poor miscibility in blends and alloys with polar polymers like nylons, polyesters, engineering thermoplastics, and so forth. This restricts their use in several new emerging technologies. One means of overcoming these drawbacks is the introduction of a small amount of polar groups onto the polymer backbone by postpolymerization reactions using the polymer as a substrate. The polar groups impart new properties to the substrate polymer without affecting the backbone properties of the polymer significantly. The objective of this paper is to briefly review some of the published literature in this area.

ISSN:1532-1797    

DOI:10.1080/15321799608009648

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor