| With the everlasting development of society and fast improvement of science and technology, polymer materials are being developed towards high performance, functional, engineering and structural materials' direction. Metallocene polymers have experienced rapid development in as short as no more than 20 years. They have not only brought a revolution to the traditional polyolefin's industry, but made a tremendous impact on traditional market for engineering plastics. Ethylene-Styrene Interpolymers (ESIs) are a series of novel metallocene polymers that have been prepared in foreign countries in the recent years, typically containing up to about 80wt.% styrene. These ESIs encompass materials ranging from semi-crystalline elastomers to amorphous thermoplastics, dependent upon the copolymer styrene content. ESIs show excellent compatability and good toghening effect to many polymers. Moreover, they possess good filling, foaming and filming properties. Extensive implorations have been carried out in advanced countries for developing ESI properties, and many primary results have been obtained. China, however, has just begun its research and development in the field of ESI. Up to present, there has been no research result reported, it is, therefore, very urgent, and essential to carry out research in this field, which can fill up the gap in the study on ESI of our nation.This paper, which is based on the research on the three ESI filling, toughening and plasticated systems, investigated the rheological properties, mechanical properties and microscopic morphology of ESI filling systems and blend alloys in broad perspectives. 1 ESI filling systemsMaterials have been produced by melt compounding based on a range of fillers, including calcium carbonate (CaCO3), aluminum trihydrate (ATH), talc and glass fibers. The properties of filled ESIs are presented and discussed, including melt rheology/processability and solid-state dynamic mechanical spectroscopy. The toughness of highly filled materials, such as indicated by elongation at rupture from tensile stress/strain behavior, is also described. The results indicate: (1) filled ESIs have shearing thinning characteristics, which is an advantage for final part fabrication; (2) fillers can improve the mechanical properties of the matrix in the existence of coupling agents; (3) glass fiber and talc can effectively improve the mechanicalproperties of ESI.2 ESI toughening systemsThe effect of ESI on the mechanical properties of PS/ESI blends was studied in this paper. The results indicate that ESI resins are compatible with polystyrene and the compatibility increases as the styrene content in the resin increases. And ESI resins are found to make toughened materials with excellent mechanical properties by blending with polystyrene (PS). The toughening effect was shown to increase as the styrene content in the ESI resin increased, peaking at an approximately 72.4% of styrene. At a low level in the blend, the ESI resin forms dispersed micro-domains of submicron size in polystyrene. At a level of 40%ESI, a co-continuous blend that was both stiff and ductile was produced.In the research for toughening K8303 resin with ESI24, we found that ESI24 could effectively improve the impact-resistant properties and rupture properties. At the content of 15%, the matrix resin could obtain the brittle-tough transition. The impact properties of the blends could reach high-toughness level; while the tensile properties experienced very little loss. Through a balanced consideration on the impact and tensile properties of blend alloys, we drew a conclusion that the content of ESI24 should be controlled to 15% to obtain an ideal overall mechanical property. ESI24 added with inadequate contents could not display good toughening effects. On the other hand, too large content, though could largely increase the impact properties of the matrix resin, its tensile properties would sacrifice to unacceptable levels.In this paper, the mechanic properties of supper PP-R/ESI24 blend alloys were studied. The... |
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