本文選題：烯烴聚合機(jī)理 + 茂金屬催化劑��； 參考：《浙江大學(xué)》2017年博士論文

【摘要】：熱塑性彈性體(TPE)具有熱塑性樹脂的可塑加工特性以及傳統(tǒng)熱固性橡膠的高彈性、高強(qiáng)度、高回彈性性質(zhì),它打破了橡膠和塑料之間的傳統(tǒng)界限,在節(jié)能、環(huán)保方面比傳統(tǒng)材料更具有經(jīng)濟(jì)和社會(huì)效益。而其中聚烯烴類的嵌段共聚物成為越來(lái)越重要的熱塑性彈性體品種。另一方面,雖然茂金屬、后過(guò)渡金屬等新一代金屬有機(jī)催化劑在生產(chǎn)高性能聚烯烴(包括TPE)上已取得巨大的成功,其催化烯烴聚合過(guò)程的微觀機(jī)理仍有許多重要環(huán)節(jié)未被充分了解,包括活性中心數(shù)(也即金屬有機(jī)配合物活化成催化中心的比例)、微觀動(dòng)力學(xué)行為及其與聚合物鏈結(jié)構(gòu)的關(guān)系等重要方面有待研究。本論文通過(guò)在金屬有機(jī)催化體系中建立酰氯淬滅法,研究了活性中心數(shù)的變化,進(jìn)而研究這類體系催化聚合體系的反應(yīng)機(jī)理和活性中心結(jié)構(gòu)。通過(guò)多種均相催化劑的烯烴共聚,制備了具有多嵌段結(jié)構(gòu)的聚烯烴共聚物,并對(duì)聚合物結(jié)構(gòu)—性能進(jìn)行了深入研究,為聚烯烴熱塑性彈性體的合成提供了新的思路及理論基礎(chǔ)。1.將噻吩-2-甲酰氯(TPCC)淬滅法應(yīng)用于金屬有機(jī)催化烯烴聚合體系中,通過(guò)研究不同催化劑、淬滅時(shí)間以及淬滅劑用量,發(fā)現(xiàn)在淬滅時(shí)間3～20min、淬滅劑量TPCC/A1 = 2～8時(shí),TPCC與活性鏈向鋁轉(zhuǎn)移產(chǎn)物之間的反應(yīng)可以忽略,TPCC能高效、專一地與活性中心進(jìn)行反應(yīng),使每條活性鏈端帶有一個(gè)噻吩基團(tuán)。淬滅后聚合物的硫含量等于活性中心數(shù)量。2.利用所建立的TPCC淬滅法。研究多種均相催化劑催化乙烯聚合過(guò)程中活性中心數(shù)以及動(dòng)力學(xué)行為的變化,發(fā)現(xiàn)(α-二亞胺)鎳催化劑的活性中心比例通常小于50%。橋聯(lián)茂金屬乙撐雙茚基二氯化鋯(Met.1)催化體系中活性中心比例與助催化劑種類有緊密關(guān)系。無(wú)橋茂金屬催化劑雙(2,4,7-三甲基茚基)二氯化鋯(Met.2)在不同助催化劑活化下均能充分活化。兩種無(wú)橋茂金屬催化劑雙(2,4,6-三甲基茚基)二氯化鋯(Met.3)和雙(2,4,5,6-四甲基茚基)二氯化鋯(Met.4),雖然在聚合反應(yīng)初期的活化率較高,但其則活性中心比例在聚合一段時(shí)間后明顯衰減。3.橋聯(lián)茂金屬M(fèi)et.1催化的乙烯均聚產(chǎn)物是由多種活性中心生成的,這些活性中心在催化特性上的差異可按照茂金屬陽(yáng)離子與其反離子構(gòu)成的離子對(duì)的疏松程度不同給出合理的解釋。以不同種類的鋁氧烷為助催化劑對(duì)不同離子對(duì)的相對(duì)含量有顯著影響,其中由助催化劑帶入的游離三甲基鋁還會(huì)參與緊密離子對(duì)的形成。橋聯(lián)茂金屬催化的丙烯均聚和乙丙共聚體系中松散離子對(duì)是主要的活性中心。Met.1在催化不同單體聚合時(shí)可達(dá)到的最高活性大小順序?yàn)?乙丙共聚乙烯均聚丙烯均聚。4.無(wú)橋茂金屬催化的乙烯均聚體系含有松散、中等解離度和緊密的離子對(duì)等多種活性中心。使用dMAO或MAO作為助催化劑均能達(dá)到很高的茂金屬活化率,而使用BHT-MAO時(shí)活化率很低。無(wú)橋茂金屬催化的丙烯均聚體系的活性中心以松散離子對(duì)為主。無(wú)橋茂金屬催化的乙丙共聚體系也含有多種活性中心,其中有利于丙烯插入的是緊密離子對(duì),且丙烯基本上是孤立地插入鏈中。5.系統(tǒng)研究了無(wú)橋茂金屬催化劑在不同反應(yīng)條件下的乙丙加壓共聚,并從中找到了有效調(diào)控共聚物結(jié)構(gòu)、性能的條件。在適中的聚合溫度、較高的乙丙投料比下,共聚物的力學(xué)性能可以得到顯著的提高。以BHT-MAO活化茂金屬制備的共聚物的拉伸行為無(wú)明顯的屈服現(xiàn)象。通過(guò)控制聚合條件(催化劑濃度25μmol/L,助催化劑BHT-MAO與催化劑摩爾比1000,聚合溫度50∞C,聚合壓力0.7 MPa,乙烯丙烯摩爾進(jìn)氣比為80 mol%:20 mol%,聚合30 min),可以制備出有一定熱塑性彈性體特性的乙丙共聚物。用三種無(wú)橋茂金屬催化劑在優(yōu)化的聚合條件下分別進(jìn)行加壓乙丙共聚,發(fā)現(xiàn)使用dMAO和BHT-MAO作為助催化劑可以有效提高所制備的共聚物的力學(xué)性能。6.用耐熱型(α-二亞胺)鎳催化劑N,N'-二(2,6-二異丙基苯基)亞乙基苊二亞胺二溴化鎳(Ni.2)催化乙烯/長(zhǎng)鏈α-烯烴共聚,得到了熔點(diǎn)12～103℃、很低的熔融焓以及較高的分子量的共聚物級(jí)分。這種共聚物具有高度支化聚乙烯鏈段和 '經(jīng)歷不同步數(shù)鏈伸直反應(yīng)的長(zhǎng)鏈α-烯烴單元交替連接成的鏈結(jié)構(gòu),其中長(zhǎng)鏈α-烯烴單元進(jìn)入主鏈及留在側(cè)基的亞甲基序列均可形成結(jié)晶相,為共聚物提供結(jié)晶型物理交聯(lián)點(diǎn),使這種共聚物也具備熱塑性彈性體的特性。本文的主要?jiǎng)?chuàng)新點(diǎn):1.將噻吩-2-甲酰氯淬滅法測(cè)定活性中心數(shù)系統(tǒng)地應(yīng)用于茂金屬等均相催化聚合體系,并確定了適宜的淬滅反應(yīng)條件。2.結(jié)合噻吩-2-甲酰氯淬滅法、GPC分峰、鏈結(jié)構(gòu)分析等研究方法,對(duì)茂金屬催化烯烴體系中的多活性中心現(xiàn)象進(jìn)行深入研究,初步揭示了其微觀機(jī)理。3.研究了無(wú)橋茂金屬催化劑催化乙烯/丙烯反應(yīng)的構(gòu)效關(guān)系和共聚產(chǎn)物的結(jié)構(gòu)與性能關(guān)系,制備了具有熱塑性彈性體特性的烯烴共聚物。4.研究了耐熱型(α-二亞胺)鎳催化劑催化的乙烯/長(zhǎng)鏈α-烯烴共聚,并制備了一種含有多個(gè)結(jié)晶性主鏈鏈段和長(zhǎng)側(cè)基的超支化聚乙烯,有望成為新型的熱塑性彈性體。
[Abstract]:The thermoplastic elastomer (TPE) has the plastic properties of thermoplastic resin and the high elasticity, high strength and high resilience of the traditional thermosetting rubber. It breaks the traditional boundary between rubber and plastics. It has more economic and social benefits than traditional materials in energy saving and environmental protection. On the other hand, the new generation of metal organic catalysts, such as metallocene and post transition metals, have achieved great success in the production of high performance polyolefin (including TPE). There are still many important links in the micromechanism of the olefin polymerization process, including the number of active centers (i. e. gold). In this paper, the changes in the number of active centers were studied in this paper by establishing acyl chloride quenching method in the metal organic catalysis system, and the reaction mechanism and activity of the catalytic polymerization system of this kind of system were investigated. The polyolefin copolymer with multi block structure was prepared by copolymerization of various homogeneous catalysts. The structure and properties of polyolefin thermoplastic elastomers were studied in depth. A new idea and theoretical basis for the synthesis of polyolefin thermoplastic elastomers (.1.) was used for the application of thiophene -2- Methoyl chloride (TPCC) quenching method to metal organic synthesis. In the catalytic olefin polymerization system, through the study of different catalysts, quenching time and the amount of quenching agent, it is found that the reaction between TPCC and the active chain to aluminum transfer products can be ignored when quenching time is 3 ~ 20min and quenching dose TPCC/A1 = 2~8, and TPCC can react with the active center to make each active chain end with one Thiophene group. The sulfur content of the polymer after quenching is equal to the number of active centers.2. using the established TPCC quenching method. The changes in the number of active centers and the dynamic behavior of various homogeneous catalysts in the process of ethylene polymerization have been studied. It is found that the active center ratio of (alpha two imide) nickel catalyst is usually less than that of 50%. bridged ethene diene. The ratio of active center in the base two zirconium chloride (Met.1) catalytic system is closely related to the type of catalyst. The non bridged metallocene catalyst (2,4,7- three methyl inyl) two zirconium chloride (Met.2) can be fully activated under the activation of different catalysts. Two kinds of non bridge metallocene catalysts (2,4,6- three methyl inyl) two zirconium chloride (Met.3) and double (2,4,5,6) - four methylinyl) two zirconium chloride (Met.4), although the activation rate at the initial stage of polymerization is high, but the proportion of the active center attenuates obviously after a period of polymerization. The ethylene homopolymer of.3. bridged metallocene Met.1 is generated by a variety of active centers, and the differences in the catalytic properties of these active centers can be based on metallocene Yang separation. Different kinds of balanes have a significant effect on the relative content of different ion pairs, and the free three methyl aluminum, which is carried by the promoter, will also participate in the formation of the compact ion pair. The highest active size of the main active center.Met.1 in the polymerization of the main active center in the polymerization system is that the ethylene homopolymer polypropylene homopolymer polypropylene homopolymer poly.4. non bridged metallocene catalyzed by the ethylene propylene homopolymer contains loose, medium dissociation and close ionic reciprocal active centers. The use of dMAO or M AO as a co catalyst can achieve high metallocene activation rate, while the activation rate of BHT-MAO is very low. The active center of the propylene homopolymer system catalyzed by non bridged metallocene is dominated by loose ions, and the ethylene propylene copolymerization system catalyzed by no bridge metallocene also contains a variety of active centers, and the propene is inserted into the compact ion pair. Propene is basically the.5. system in the isolated insertion chain to study the ethylene propylene polymerization under different reaction conditions for the non bridge metallocene catalyst, and found the conditions to effectively regulate the structure and properties of the copolymer. The mechanical properties of the copolymers can be significantly improved at moderate polymerization temperature and higher ethylene propylene feed ratio. BH The tensile behavior of the copolymers prepared by T-MAO activated metallocene has no obvious yield. By controlling the polymerization conditions, the catalyst concentration is 25 mu mol/L, the catalyst BHT-MAO and the catalyst molar ratio are 1000, the polymerization temperature is 50 infinity C, the polymerization pressure is 0.7 MPa, the molar ratio of ethylene to propylene is 80 mol%, 20 mol%, and 30 min is polymerized, and a certain heat can be prepared. Ethylene propylene copolymer characterized by plastic elastomer. Using three kinds of non bridge metallocene catalysts under optimal polymerization conditions, the copolymerization of EPDM was carried out under the optimized polymerization conditions. It was found that the use of dMAO and BHT-MAO as a co catalyst can effectively improve the mechanical properties of the prepared copolymers,.6. with the heat resistant (alpha two imide) nickel catalyst N, N'- two (2,6- two isopropyl benzene). The ethylene / two imide dibromide dibromide (Ni.2) catalyzes the copolymerization of ethylene / long chain alpha olefin, and the melting point 12~103, the low melting enthalpy and the high molecular weight copolymer grade. This copolymer has a highly branched polyethylene chain and a chain of long chain alpha olefin units that undergo an unsynchronized chain extension reaction. Structure, in which the long chain alpha olefin unit can enter the main chain and the methylene sequence left in the side group can form the crystalline phase, providing the crystalline physical crosslinking point for the copolymers, making the copolymer also possess the properties of the thermoplastic elastomer. The main innovation of this paper is: 1. the determination of the number of active centers by the thiophene -2- Methoyl chloride quenching method is applied to the metallocene system. Metal homogeneous homogeneous catalytic polymerization system, and the suitable quenching reaction conditions.2. combined with thiophene -2- Methoyl chloride quenching, GPC peak, chain structure analysis and other research methods, the multi activity center phenomenon in the olefin catalyzed by metallocene catalyzed by metallocene is deeply studied, and its micro mechanism.3. has been revealed to study the catalysis of non bridge metallocene catalyst. The relationship between the structure-activity relationship of ethylene / propylene and the structure and properties of the copolymers, the olefin copolymer.4. with the properties of the thermoplastic elastomer was prepared to study the ethylene / long chain alpha olefin copolymerization catalyzed by the heat-resistant (alpha two imide) nickel catalyst, and a hyperbranched poly (b) containing a number of crystalline main chain segments and long side groups was prepared. It is expected to be a new type of thermoplastic elastomer.

【學(xué)位授予單位】：浙江大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2017
【分類號(hào)】：TQ334;O643.3
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本文編號(hào)：1782432