【正文】 ]=25，Mw=390000[AlEt3 ]/[Ti]=20，Mw=130000Mw=96000MWD=Syndio.，Mw=135000Syndio.=Syndio.95目前報(bào)道的sPS幾乎全部是以金屬鈦原子為中心原子的鈦茂化合物，少數(shù)鋯茂化合物可合成sPS，但其催化活性比相應(yīng)的鈦茂化合物要低得多；釩系不能合成純的sPS；鎳系只能合成iPS，鈀、鉈、鉻、鈷系根本不能合成有規(guī)立構(gòu)的PS。在環(huán)上引入苯環(huán)，催化劑的活性都下降。這是因?yàn)橹鞔呋瘎┡c助催化劑形成陽離子型活性中心時(shí)，輔助配體只影響活性中心的形成過程，一旦形成聚合活性中心，輔助配體全被助催化劑奪走，鏈增長(zhǎng)，空間定向選擇性及活性中心穩(wěn)定性都由主配體結(jié)構(gòu)決定。使用的催化劑除常用的無水三氯化鋁外，還有無水氯化鋅、氯化錫、三氯化硼等。在FriedelCrafts反應(yīng)中，烷基化反應(yīng)和?；磻?yīng)對(duì)于三氯化鋁的用量有所不同。應(yīng)該結(jié)合反應(yīng)特點(diǎn)綜合考慮。但由于乙酞基團(tuán)體積較小，乙酸化苯乙烯單元仍然能進(jìn)入晶體晶格中，因而對(duì)晶體的完善性影響較小。通過大分子引發(fā)劑引發(fā)單體進(jìn)行聚合反應(yīng)，可以合成接枝、嵌段聚合物。對(duì)影響反應(yīng)的諸因素進(jìn)行探討。近年來，國外一些公司在近300家加工應(yīng)用單位進(jìn)行了材料的sPS的試用，初步證實(shí)作為工程塑料的應(yīng)用前景相當(dāng)廣闊。(3)汽車部件：sPS在汽車刮水器、空調(diào)元件、點(diǎn)火器元件、通風(fēng)罩和保險(xiǎn)杠等方面有一定的潛在市場(chǎng)。只有進(jìn)行大量的sPS性能與應(yīng)用研究，選準(zhǔn)其具體應(yīng)用領(lǐng)域，sPS才能真正作為商品進(jìn)入市場(chǎng)。如上所述，sPS是一種正在開發(fā)中的具有優(yōu)異特性和潛在應(yīng)用市場(chǎng)的新型工程塑料。參考文獻(xiàn)[1]Ishihara N, Seimiya T, Kuramoto M, Hoi M. 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