| 摘要 |
<p>Linear, head to tail, high molecular weight polymers of an alpha-olefin of general formula CH2 = CHR, where R is a lower aliphatic radical are produced by preparing a polymerisate by the method discussed in the parent Specification and thereafter extracting it stepwise with a series of solvents which have increasing dissolving powers so as to dissolve first only the amorphous nonisotactic polymers and then fractions consisting of block polymers with increasing crystallinity percentages, leaving the isotactic polymers undissolved. Thus where the polymer is from propylene the extraction is conducted stepwise with ethyl ether which dissolves substantially the non-isotactic amorphous polymers and then in succession with isopropyl ether and n-heptane. Poly-alpha-butenes and poly-alpha-pentenes are also specified. Extruded and moulded articles may be prepared from the products.</p> |
