当前位置：
X-MOL 学术
›
J. Appl. Polym. Sci.
›
论文详情
Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
Octadecyl‐modified silica supports for metallocene catalyst applied in ethylene polymerization
Journal of Applied Polymer Science ( IF 2.7 ) Pub Date : 2020-09-24 , DOI: 10.1002/app.49961 Arthur Alaim Bernardes 1 , Cintia Salomão Pinto Zarth 1 , Fernanda Soares Gossler 1 , Antonio Marchi Netto 1 , Rodrigo Brambilla 1
Journal of Applied Polymer Science ( IF 2.7 ) Pub Date : 2020-09-24 , DOI: 10.1002/app.49961 Arthur Alaim Bernardes 1 , Cintia Salomão Pinto Zarth 1 , Fernanda Soares Gossler 1 , Antonio Marchi Netto 1 , Rodrigo Brambilla 1
Affiliation
|
Chemical modification of silica‐based supports is an alternative route for modulating the active sites of metallocene catalysts, presenting the potential to obtain polyethylenes with improved properties. Therefore, this work investigates the effect of octadecylsilane content in silica support on the behavior of resulting supported metallocene catalysts on ethylene polymerization. For this propose, a series of octadecyl‐modified silicas whit different amounts of octadecyl (ODS) groups were synthesized by a modified Stöber sol–gel method and then applied as supports for a metallocene catalyst. The supported metallocene catalysts were evaluated in ethylene polymerization and ethylene/1‐hexene copolymerization reactions. Besides, studies of the growth kinetics of polyethylene particles in a gas phase reactor were performed using videomicroscopy. The octadecylsilane content in the supports was in the range of 0.2 to 1.4 mmol g−1. DRIFTS and 13C CP/MAS NMR results showed a predominance of an all‐trans octadecyl chain conformation. SEM images showed spherical particle morphology for silicas having octadecylsilane content up to 0.6 mmol g−1. The supported catalysts presented activity in ethylene polymerization in the range of 1100–1900 kg PE molZr−1 h−1 bar−1. The surface polarity of the catalyst influenced the molar mass of the resulting polyethylene. The increase of the ODS content on the silica surface led to a supported catalyst with slower kinetic behavior in the gas phase, which might be attributed to the diffusive effects of the octadecyl layer on the catalyst surface.
中文翻译：
用于乙烯聚合的茂金属催化剂的十八烷基改性二氧化硅载体
二氧化硅基载体的化学改性是调节茂金属催化剂活性位点的另一种途径，具有获得性能改善的聚乙烯的潜力。因此，这项工作研究了二氧化硅载体中十八烷基硅烷含量对所得载体茂金属催化剂在乙烯聚合反应中行为的影响。对于该建议，通过改良的Stöber溶胶-凝胶法合成了一系列十八烷基改性的二氧化硅，其中十八烷基（ODS）基团的数量不同，然后用作茂金属催化剂的载体。在乙烯聚合和乙烯/ 1-己烯共聚反应中评估了负载型茂金属催化剂。此外，使用视频显微镜对气相反应器中聚乙烯颗粒的生长动力学进行了研究。-1。DRIFTS和13 C CP / MAS NMR结果表明，全反式十八烷基链构象占优势。SEM图像显示了十八烷基硅烷含量高达0.6 mmol g -1的二氧化硅的球形颗粒形态。负载型催化剂在乙烯聚合反应中的活性范围为1100–1900 kg PE molZr -1 h -1 bar -1。催化剂的表面极性影响所得聚乙烯的摩尔质量。二氧化硅表面上ODS含量的增加导致负载型催化剂在气相中具有较慢的动力学行为，这可能归因于十八烷基层在催化剂表面上的扩散作用。
更新日期：2020-12-01
中文翻译：
用于乙烯聚合的茂金属催化剂的十八烷基改性二氧化硅载体
二氧化硅基载体的化学改性是调节茂金属催化剂活性位点的另一种途径，具有获得性能改善的聚乙烯的潜力。因此，这项工作研究了二氧化硅载体中十八烷基硅烷含量对所得载体茂金属催化剂在乙烯聚合反应中行为的影响。对于该建议，通过改良的Stöber溶胶-凝胶法合成了一系列十八烷基改性的二氧化硅，其中十八烷基（ODS）基团的数量不同，然后用作茂金属催化剂的载体。在乙烯聚合和乙烯/ 1-己烯共聚反应中评估了负载型茂金属催化剂。此外，使用视频显微镜对气相反应器中聚乙烯颗粒的生长动力学进行了研究。-1。DRIFTS和13 C CP / MAS NMR结果表明，全反式十八烷基链构象占优势。SEM图像显示了十八烷基硅烷含量高达0.6 mmol g -1的二氧化硅的球形颗粒形态。负载型催化剂在乙烯聚合反应中的活性范围为1100–1900 kg PE molZr -1 h -1 bar -1。催化剂的表面极性影响所得聚乙烯的摩尔质量。二氧化硅表面上ODS含量的增加导致负载型催化剂在气相中具有较慢的动力学行为，这可能归因于十八烷基层在催化剂表面上的扩散作用。
京公网安备 11010802027423号