With BF3 (and isobutylene as the monomer), it was demonstrated that the polymerization is possible only in the presence of traces of traces of water or alcohol. If one eliminates the trace of water, BF3 alone does not give rise to polymerization. Water or alcohols are necessary in order to allow the formation of the BF3-complex and the initiator cation according to the above reactions. However, one should not describe the water or the alcohol as a “cocatalyst”.

BF3为引发剂（异丁烯为单体），证明仅在痕量水或乙醇的存在下聚合反应是可以进行

的。如果消除痕量的水，单纯的BF3不会引发聚合反应。按照上述反应为了能形成BF3-络合物和引发剂离子水或乙醇是必需的。但是不应将水或乙醇描述成“助催化剂”。 Just as by radical polymerization, one can also prepare copolymers by ionic

polymerization, for example, anionic copolymers of styrene and butadiene, or cationic copolymers of isobutylene and styrene, or isobutylene and viny ethers, etc. As has been described in detail with radical polymerization, one can characterize each monomer pair by so-called reactivity ratios r1 and r2. The actual values of these two parameters are, however, different from those used for radical copolymerization.

正与自由基聚合反应一样，通过离子聚合反应也能制备共聚物，例如，苯乙烯-丁二

烯阴离子共聚物，或异丁烯-苯乙烯阳离子共聚物，或异丁烯-乙烯基醚共聚物，等等。正如对自由基型聚合已经详细描述过那样，人们可以用所谓的竞聚率r1和r2来表征每单体对。然而，这两个参数的实际意义不同于那些用于自由基共聚合反应的参数。

---Vollmert B. Polymer Chemistry. Berlin: Sping-Verlag, 1973.163

PART B 聚合反应工程

C 聚合物材料的加工、性能和应用

UNIT 21 Polymer Processing

第二十一单元 聚合物加工

Polymer processing , in its most general context , involves the transformation

of a solid ( sometimes liquid ) polymeric resin , which is in a random form (e. g. powder, pellets , beads ), to a solid plastics product of specified shape ,