{"title":"Synthesis and ethylene polymerization reaction of dendritic titanium catalysts.","authors":"Tianyu Lan, Liduo Chen, Na Zhang, Jun Wang","doi":"10.1080/15685551.2020.1868666","DOIUrl":null,"url":null,"abstract":"<p><p>The 1.0 G dendrimer (C<sub>22</sub>H<sub>48</sub>N<sub>10</sub>O<sub>4</sub>),3,5-di-tert-butylsalicylaldehyde and TiCl<sub>4</sub> · 2THF were used as the synthetic materials, and the dendritic salicylaldehyde imide ligand with substituent hindrance and its titanium catalyst were synthesized by the condensation reaction of schiff base. The structure of the synthesized products was characterized by infrared spectroscopy, nuclear magnetic resonance hydrogen spectroscopy, ultraviolet spectroscopy, electrospray mass spectrometry, and inductively coupled plasma mass spectrometry, The actual structure is consistent with the theoretical design structure. Activated methylaluminoxane (MAO) was used as a catalyst precursor for ethylene polymerization in the process of ethylene catalytic. The effects of ethylene polymerization were studied in terms of the Al/Ti molar ratio, reaction time, reaction temperature, polymerization pressure, and ligand structure of the catalyst. The results show at the reaction temperature of 25°C, the reaction time was 30 min, and the ethylene pressure was 1.0 MPa and Al/Ti was 1,000, the catalytic activity can reach 78.56 kg PE/(mol Ti.h). Furthermore, high-temperature GPC-IR, DSC, and torque rheometer were used to characterized the microstructure, thermal properties, and viscoelastic state of polyethylene samples obtained. The results showed that the product was ultra-high-molecular-weight polyethylene.</p>","PeriodicalId":11170,"journal":{"name":"Designed Monomers and Polymers","volume":null,"pages":null},"PeriodicalIF":1.8000,"publicationDate":"2021-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/15685551.2020.1868666","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Designed Monomers and Polymers","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1080/15685551.2020.1868666","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"POLYMER SCIENCE","Score":null,"Total":0}
引用次数: 0
Abstract
The 1.0 G dendrimer (C22H48N10O4),3,5-di-tert-butylsalicylaldehyde and TiCl4 · 2THF were used as the synthetic materials, and the dendritic salicylaldehyde imide ligand with substituent hindrance and its titanium catalyst were synthesized by the condensation reaction of schiff base. The structure of the synthesized products was characterized by infrared spectroscopy, nuclear magnetic resonance hydrogen spectroscopy, ultraviolet spectroscopy, electrospray mass spectrometry, and inductively coupled plasma mass spectrometry, The actual structure is consistent with the theoretical design structure. Activated methylaluminoxane (MAO) was used as a catalyst precursor for ethylene polymerization in the process of ethylene catalytic. The effects of ethylene polymerization were studied in terms of the Al/Ti molar ratio, reaction time, reaction temperature, polymerization pressure, and ligand structure of the catalyst. The results show at the reaction temperature of 25°C, the reaction time was 30 min, and the ethylene pressure was 1.0 MPa and Al/Ti was 1,000, the catalytic activity can reach 78.56 kg PE/(mol Ti.h). Furthermore, high-temperature GPC-IR, DSC, and torque rheometer were used to characterized the microstructure, thermal properties, and viscoelastic state of polyethylene samples obtained. The results showed that the product was ultra-high-molecular-weight polyethylene.
期刊介绍:
Designed Monomers and Polymers ( DMP) publishes prompt peer-reviewed papers and short topical reviews on all areas of macromolecular design and applications. Emphasis is placed on the preparations of new monomers, including characterization and applications. Experiments should be presented in sufficient detail (including specific observations, precautionary notes, use of new materials, techniques, and their possible problems) that they could be reproduced by any researcher wishing to repeat the work.
The journal also includes macromolecular design of polymeric materials (such as polymeric biomaterials, biomedical polymers, etc.) with medical applications.
DMP provides an interface between organic and polymer chemistries and aims to bridge the gap between monomer synthesis and the design of new polymers. Submssions are invited in the areas including, but not limited to:
-macromolecular science, initiators, macroinitiators for macromolecular design
-kinetics, mechanism and modelling aspects of polymerization
-new methods of synthesis of known monomers
-new monomers (must show evidence for polymerization, e.g. polycondensation, sequential combination, oxidative coupling, radiation, plasma polymerization)
-functional prepolymers of various architectures such as hyperbranched polymers, telechelic polymers, macromonomers, or dendrimers
-new polymeric materials with biomedical applications