摘要:
Disclosed is a method for manufacturing a polylactic acid film. More specifically, the present invention relates to a method for stably and effectively obtaining optimized stereocomplex crystals through specified boiling point and evaporation time of a solvent allowing the content of stereocomplex crystals to be 100%.
摘要:
Disclosed is a method for manufacturing a polylactic acid film. More specifically, the present invention relates to a method for stably and effectively obtaining optimized stereocomplex crystals through specified boiling point and evaporation time of a solvent allowing the content of stereocomplex crystals to be 100%.
摘要:
The present invention relates to a polypropylene nanocomposite comprising (a) about 1 wt % to about 40 wt % of an acid- or acid anhydride-modified polypropylene; (b) about 0.1 wt % to about 50 wt % of an organically modified layered silicate; and (c) about 30 wt % to about 90 wt % of a nonpolar polypropylene, wherein the acid- or anhydride-modified polypropylene has a molecular weight that is lower than that of the nonpolar polypropylene, and wherein the polypropylene nanocomposite has a linear thermal expansion coefficient ranging from about 4×10−5/° C. to about 9×10−5/° C. The density and linear thermal expansion coefficient of these nanocomposites are, respectively, 10% to 20% and 20% to 40% less than conventional polypropylene composites and can be used to form durable molded products with superior dimensional stability, good tensile strength, good moldability, and high thermal resistance.
摘要:
A polypropylene resin composition comprises (1) 40 to 99% by weight of a polypropylene resin; (2) 1 to 60% by weight of an ethylene/alpha-olefin copolymer elastomer; (3) 20 to 50 parts by weight of a low molecular weight polypropylene resin modified with unsaturated carboxylic acid or its anhydride, and (4) 0.1 to 20 parts by weight of an epoxy resin represented by the following chemical formula I: ##STR1## wherein n is an integer of 1 to 4 and A is a multivalent group having a bond number of n and is selected from bisphenol A-type ethers, propylene oxide-type ethers and ethylene oxide-type ethers, the components (3) and (4) being based on 100 parts by weight of the components (1) and (2) in total. The composition is suited for polypropylene materials to be painted, such as automobile bumpers, by virtue of its superior paint adhesion even under the condition of no pretreatments.