Anionic Copolymerization - Explore the Science & Experts | ideXlab

Scan Science and Technology

Contact Leading Edge Experts & Companies

Anionic Copolymerization

The Experts below are selected from a list of 246 Experts worldwide ranked by ideXlab platform

Yang Li – 1st expert on this subject based on the ideXlab platform

  • synchronous regulation of periodicity and monomer sequence during living Anionic Copolymerization of styrene and dimethyl 4 1 phenylvinyl phenyl silane dpe sih
    Macromolecules, 2018
    Co-Authors: Wei Huang, Lincan Yang, Heyu Shen, Yang Li

    Abstract:

    To investigate the specific strategy for sequence regulation with living Anionic polymerization, three sequence-defined polymers with similar number of SiH functional groups per chain but totally different periodicities which distributed as gradient, tandem, and symmetrical structures were synthesized. Through different feeding methods and coupling reaction after polymerization during the living Anionic Copolymerization of styrene (St) and dimethyl-[4-(1-phenylvinyl)phenyl]silane (DPE-SiH), the synchronous regulation of monomer sequence and functionalized block periodicity in polymer chains was successfully achieved. The monomer sequence distributions in these three structures were confirmed by in situ 1H NMR. As the monomer sequence and block periodicity are synchronously regulated, this effort could promote the further development of the sequence regulation and the design of novel functionalized polymers with living Anionic polymerization method, and the strategy we investigated also can improve the nov…

  • sequence determination and regulation in the living Anionic Copolymerization of styrene and 1 1 diphenylethylene dpe derivatives
    Macromolecular Chemistry and Physics, 2017
    Co-Authors: Yang Li

    Abstract:

    The living Anionic Copolymerization of styrene (St) and 1,1-diphenylethylene (DPE) derivatives were carried out to investigate how the DPE units are distributed along the polymer chain. Based on the combination of timing sample method and exact characterizations, the sequence determination method was established to reveal the sequential distribution of DPE units along the functionalized chains. In the Copolymerization of St and DPE-SiH, when DPE-SiH was excessively fed, a strictly alternating structure can be prepared. As the feed ratios of S/D increased, a gradient structure was obtained. Additionally, when the substituent structure of the DPE derivatives changed, the sequence structure could be regulated. It has been confirmed in the Copolymerization of St and DPE-SiH/OMe or DPE-SiH/NMe2, that the electron-donating group (-OMe or -NMe2) was introduced into DPE-SiH. Then, the preliminary sequence regulation method was found. Meanwhile the sequence-determined grafting was investigated, and bottlebrush polymers with sequence-determined branches were successfully synthesized.

  • sequence regulation in the living Anionic Copolymerization of styrene and 1 4 dimethylaminophenyl 1 phenylethylene by modification with different additives
    Polymer Chemistry, 2017
    Co-Authors: Wei Huang, Heyu Shen, Yang Li

    Abstract:

    The amino-functionalized DPE derivative 1-(4-dimethylaminophenyl)-1-phenylethylene (DPE-NMe2) was used in a living Anionic Copolymerization with styrene (St), and the corresponding sequence structures of the copolymers were investigated using the sequence determination method. The Copolymerization of St and DPE-NMe2 was neatly carried out at 24 °C, and a gradient sequence structure was obtained, with the DPE-NMe2 units incrementally distributed along the copolymer chains. For the facile regulation of the sequence distribution of the DPE-NMe2 units in the copolymer chains, the additives tetrahydrofuran (THF) or sodium 2,3-dimethylpentan-3-olate (NaODP) were introduced into the Copolymerization reactions. The detailed investigations of the conversions, reactivity ratios, and sequence structures indicated that THF had a restraining effect on the incorporation of DPE-NMe2 units into the copolymer chains, and the variations in the corresponding conversions and reactivity ratios also demonstrated this tendency. In addition, a stimulatory effect was observed in the Copolymerization when NaODP was used as an additive. On comparing the sequence distribution of DPE-NMe2 units in the chains among these three Copolymerization reactions, it was found that NaODP promoted a higher incorporation of DPE-NMe2 into the chains than the other two conditions. This conclusion was also confirmed by the kinetic results. The values of the reactivity ratios were 9.1, 29.8 and 6.9 for the neat, THF, and NaODP conditions, respectively. For the neat, THF and NaODP conditions, the apparent reactivity ratios for styrene (KSt) were calculated to be 0.0548 min−1, 0.209 min−1 and 0.107 min−1, respectively, while the apparent reactivity ratios for DPE-NMe2 (KDPE) were calculated to be 1.82 × 10−3 min−1, 7.42 × 10−4 min−1 and 6.17 × 10−3 min−1, respectively.

Yurong Wang – 2nd expert on this subject based on the ideXlab platform

  • the determination of sequence distribution in the living Anionic Copolymerization of styrene and strong electron donating dpe derivative 1 1 bis 4 n n dimethylanimophenyl ethylene
    Polymer, 2016
    Co-Authors: Wei Huang, Heyu Shen, Lingling Wu, Yang Li, Yurong Wang

    Abstract:

    Abstract Sequence distribution in the Living Anionic Copolymerization of Styrene and strong electron-donating DPE derivative, i.e. the 1,1-bis(4- N,N -dimethylanimophenyl)ethylene (DPE-(NMe 2 ) 2 ), was investigated by a timing-sample method. The target taken samples were characterized by SEC and 1 H NMR in detail According to the research data based on integrating all the taken samples, the synthesized copolymer exhibited gradient structure that most polar dimethylamino groups distributed at the end section along whole polymer chains. In addition, the apparent rate constants of styrene and DPE-(NMe 2 ) 2 were calculated (at 24 °C) as follows: K st  = 0.036 min −1 (R 2  = 0.995), K DPE  = 8.40 × 10 −5  min −1 (R 2  = 0.998), respectively. It is hardly to prepare the alternating structure just through increasing the monomer feed ratios.

  • synthesis of sequence determined bottlebrush polymers based on sequence determination in living Anionic Copolymerization of styrene and dimethyl 4 1 phenylvinyl phenyl silane
    Polymer Chemistry, 2016
    Co-Authors: Q Wang, Lincan Yang, Heyu Shen, Yurong Wang, Wei Huang, Wei Sang, Xichen Gong, Yang Li

    Abstract:

    Sequence-determined bottlebrush polymers in which the branches are distributed with determined sequential arrangements are precisely, efficiently and conveniently synthesized. Living Anionic polymerization and hydrosilylation were used to synthesize the backbones, branches and bottlebrushes. Sequence-determined backbones, which include perfectly alternating and gradient structures, were obtained by controlling the monomer feed ratios during the living Anionic Copolymerization of styrene and dimethyl(4-(1-phenylvinyl)phenyl)silane (DPE-SiH). In addition, the sequential arrangements of branch points in gradient copolymers, i.e., SiH groups, were precisely determined using the timing-sample method under high-vacuum conditions. Then, the branches were conveniently grafted onto the backbones with a corresponding distribution of SiH groups via efficient hydrosilylation. The overall efficiency of the coupling reaction was greater than 91%. The solution properties of the synthesized bottlebrush polymers were investigated, and the results indicated that the sequence of branches may exert an influence on the branching factor (g′) and the hydrodynamic radius (Rh).

  • In-chain multi-functionalized random butadiene–styrene copolymer via Anionic Copolymerization with 1,1-bis(4-dimethylaminophenyl)ethylene: synthesis and its application as a rubber matrix of carbon black-based composite
    Journal of Materials Science, 2014
    Co-Authors: Lingling Wu, Yurong Wang, Hongwei Ma, Qiuyun Wang, Li Li, Yang Li

    Abstract:

    In-chain multi-functionalized random butadiene–styrene copolymer possessing definite dimethylamino groups along the polymer backbone, poly(butadiene-co-styrene-co-1,1-bis(4-dimethylaminophenyl)ethylene) (poly(Bd-co-St-co-BDADPE)), has been designed and synthesized via living Anionic Copolymerization of excess BDADPE with butadiene and styrene in benzene at 50 °C, using sec-butyllithium as initiator. The incorporation of BDADPE unit results in increases both in glass transition temperature and thermal decomposition temperature of the terpolymers. Such multiple dimethylamino groups along the rubber backbone effectively improve the dispersity of carbon black (CB) in the corresponding composites, as verified by scanning electronic microscopy observation. Also the tensile strength, elongation at break and the value of dynamic loss coefficient at 0 °C of the CB/poly(Bd-co-St-co-BDADPE) vulcanized composites, are significantly enhanced. This in-chain multi-functionalization of matrix rubber via Anionic Copolymerization employing BDADPE as copolymerizable monomer, provides a facile and effective method to prepare CB-based rubber composites with improved tensile strength and elongation at break, as well as good wet skid resistance.

Wei Huang – 3rd expert on this subject based on the ideXlab platform

  • synchronous regulation of periodicity and monomer sequence during living Anionic Copolymerization of styrene and dimethyl 4 1 phenylvinyl phenyl silane dpe sih
    Macromolecules, 2018
    Co-Authors: Wei Huang, Lincan Yang, Heyu Shen, Yang Li

    Abstract:

    To investigate the specific strategy for sequence regulation with living Anionic polymerization, three sequence-defined polymers with similar number of SiH functional groups per chain but totally different periodicities which distributed as gradient, tandem, and symmetrical structures were synthesized. Through different feeding methods and coupling reaction after polymerization during the living Anionic Copolymerization of styrene (St) and dimethyl-[4-(1-phenylvinyl)phenyl]silane (DPE-SiH), the synchronous regulation of monomer sequence and functionalized block periodicity in polymer chains was successfully achieved. The monomer sequence distributions in these three structures were confirmed by in situ 1H NMR. As the monomer sequence and block periodicity are synchronously regulated, this effort could promote the further development of the sequence regulation and the design of novel functionalized polymers with living Anionic polymerization method, and the strategy we investigated also can improve the nov…

  • sequence regulation in the living Anionic Copolymerization of styrene and 1 4 dimethylaminophenyl 1 phenylethylene by modification with different additives
    Polymer Chemistry, 2017
    Co-Authors: Wei Huang, Heyu Shen, Yang Li

    Abstract:

    The amino-functionalized DPE derivative 1-(4-dimethylaminophenyl)-1-phenylethylene (DPE-NMe2) was used in a living Anionic Copolymerization with styrene (St), and the corresponding sequence structures of the copolymers were investigated using the sequence determination method. The Copolymerization of St and DPE-NMe2 was neatly carried out at 24 °C, and a gradient sequence structure was obtained, with the DPE-NMe2 units incrementally distributed along the copolymer chains. For the facile regulation of the sequence distribution of the DPE-NMe2 units in the copolymer chains, the additives tetrahydrofuran (THF) or sodium 2,3-dimethylpentan-3-olate (NaODP) were introduced into the Copolymerization reactions. The detailed investigations of the conversions, reactivity ratios, and sequence structures indicated that THF had a restraining effect on the incorporation of DPE-NMe2 units into the copolymer chains, and the variations in the corresponding conversions and reactivity ratios also demonstrated this tendency. In addition, a stimulatory effect was observed in the Copolymerization when NaODP was used as an additive. On comparing the sequence distribution of DPE-NMe2 units in the chains among these three Copolymerization reactions, it was found that NaODP promoted a higher incorporation of DPE-NMe2 into the chains than the other two conditions. This conclusion was also confirmed by the kinetic results. The values of the reactivity ratios were 9.1, 29.8 and 6.9 for the neat, THF, and NaODP conditions, respectively. For the neat, THF and NaODP conditions, the apparent reactivity ratios for styrene (KSt) were calculated to be 0.0548 min−1, 0.209 min−1 and 0.107 min−1, respectively, while the apparent reactivity ratios for DPE-NMe2 (KDPE) were calculated to be 1.82 × 10−3 min−1, 7.42 × 10−4 min−1 and 6.17 × 10−3 min−1, respectively.

  • the determination of sequence distribution in the living Anionic Copolymerization of styrene and strong electron donating dpe derivative 1 1 bis 4 n n dimethylanimophenyl ethylene
    Polymer, 2016
    Co-Authors: Wei Huang, Heyu Shen, Lingling Wu, Yang Li, Yurong Wang

    Abstract:

    Abstract Sequence distribution in the Living Anionic Copolymerization of Styrene and strong electron-donating DPE derivative, i.e. the 1,1-bis(4- N,N -dimethylanimophenyl)ethylene (DPE-(NMe 2 ) 2 ), was investigated by a timing-sample method. The target taken samples were characterized by SEC and 1 H NMR in detail According to the research data based on integrating all the taken samples, the synthesized copolymer exhibited gradient structure that most polar dimethylamino groups distributed at the end section along whole polymer chains. In addition, the apparent rate constants of styrene and DPE-(NMe 2 ) 2 were calculated (at 24 °C) as follows: K st  = 0.036 min −1 (R 2  = 0.995), K DPE  = 8.40 × 10 −5  min −1 (R 2  = 0.998), respectively. It is hardly to prepare the alternating structure just through increasing the monomer feed ratios.