Macromolecular Reaction Engineering

Cover image for Vol. 9 Issue 4

Early View (Online Version of Record published before inclusion in an issue)

Editor-in-Chief: Kirsten Severing, Editor: Stefan Spiegel

Online ISSN: 1862-8338

Associated Title(s): Macromolecular Chemistry and Physics, Macromolecular Materials and Engineering, Macromolecular Rapid Communications, Macromolecular Theory and Simulations

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  1. Full Papers

    1. Using a Novel CFD Model to Assess the Effect of Mixing Parameters on Emulsion Polymerization

      Shideh Fathi Roudsari, Ramdhane Dhib and Farhad Ein-Mozaffari

      Article first published online: 11 AUG 2015 | DOI: 10.1002/mren.201500019

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      CFD is employed to study the effect of mixing on emulsion polymerization. The validated model incorporates kinetics, population balance, and velocity gradients. Nucleation and growth rates are employed in the population balance model. Effects of mixing on conversion, particle size, and number density are studied. CFD model enables us to optimize the design parameters for emulsion polymerization.

    2. Some Factors Affecting the Molecular Weight Distribution (MWD) in Low Density Polyethylene Multizone Autoclave Polymerization Reactors

      Enrique Saldívar-Guerra, Almendra Ordaz-Quintero, Ramiro Infante-Martínez, Jorge Herrera-Ordóñez, Luis Villarreal-Cárdenas, Diana Ramírez-Wong, Evelia Rivera-Rodríguez, Rodolfo Flores-Flores and Luis Miramontes-Vidal

      Article first published online: 21 JUL 2015 | DOI: 10.1002/mren.201500030

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      This paper discusses the effect of several factors, including the pressure and temperature conditions used in the reactor, on the MWD, which is one of the main features of LDPE. Simulations with the Polyred software package provide a set of kinetic parameters that reproduce, using realistic conditions, the observed trends in number average molecular weight and MWD dispersity in the commercial multizone autoclave reactor.

    3. Challenges and Opportunities in Continuous Production of Emulsion Polymers: a Review

      José M. Asua

      Article first published online: 14 JUL 2015 | DOI: 10.1002/mren.201500032

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      Profit margin reduction and global competition are pushing emulsion polymer producers to consider process intensification that mainly relies on the replacement of semicontinuous reactors by continuous ones. In this work, the challenges in the continuous production of emulsion polymers are discussed and ways in which the challenges can be transformed in opportunities are reviewed.

    4. Continuous Tanks-in-Series Process for Free-Radical Polymerization with Long-Chain Branching and Scission: Effect of the Order of a Large Tank

      Hidetaka Tobita

      Article first published online: 7 JUL 2015 | DOI: 10.1002/mren.201500031

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      Tanks-in-series model for free-radical polymerization that involves simultaneous long-chain branching and scission is generalized to investigate the effect of the sequence number n of a big reactor, finding that the largest weight-average MW is obtained for n = 1. The full distributions of MW, the branching density and the radii of gyration are investigated to propose a novel reactor design strategy.

    5. Growth of Polyethylene Nanofibrils Over rac-Et(Indenyl)2ZrCl2/MAO Catalyst Supported on Silica Nanotubes

      Sang Yool Lee, Joong Jin Han, Sang Bok Lee and Kyu Yong Choi

      Article first published online: 6 JUL 2015 | DOI: 10.1002/mren.201500022

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      Silica nanotubes deposited with a metallocene catalyst polymerize ethylene to nanofibrils that extrude out from the nanoscale channels as intertwined bundles. This work shows that the basic dimension of polyethylene nanofibrils at the catalyst surface is 30–35 nm diameter fibrils of high crystallinity. The catalytic silica nanotubes also offer good accessibility for monomer and hence high initial polymerization rate.

    6. Poly(3-hydroxybutirate-co-3-hydroxyvalerate)–Polystyrene Hybrid Nanoparticles via Miniemulsion Polymerization

      Fernanda Vitória Leimann, Cristiane Costa, Odinei Hess Gonçalves, Anna Musyanovych, Katharina Landfester, Claudia Sayer and Pedro Henrique Hermes de Araújo

      Article first published online: 6 JUL 2015 | DOI: 10.1002/mren.201500023

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      In the present work, a novel hybrid polymer is synthesized with PHBV and PS by miniemulsion polymerization. Nanoparticles presenting narrow size distribution, a high grafting yield, and the hybrid formation is confirmed by FTIR and DSC. The new material presents different thermal characteristics enabling its use for new applications.

    7. Modeling Acrylic Acid Radical Polymerization in Aqueous Solution

      Nils F. G. Wittenberg, Calista Preusser, Hendrik Kattner, Marek Stach, Igor Lacík, Robin A. Hutchinson and Michael Buback

      Article first published online: 11 JUN 2015 | DOI: 10.1002/mren.201500017

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      The complexities of aqueous-phase polymerization of non-ionized acrylic acid are captured in a model that considers the formation of midchain radicals, the influence of radical chain length on termination kinetics, and the influence of monomer concentration on propagation kinetics. The model is verified against monomer conversion profiles, polymer branching levels, and molar mass distributions collected over a range of experimental conditions.

  2. Reviews

    1. Model-Based Production of Polymer Chains Having Precisely Designed End-to-End Gradient Copolymer Composition and Chain Topology Distributions in Controlled Radical Polymerization, A Review

      Xiaohui Li, Shaoning Liang, Wen-Jun Wang, Bo-Geng Li, Yingwu Luo and Shiping Zhu

      Article first published online: 15 MAY 2015 | DOI: 10.1002/mren.201500012

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      This article summarizes the recent development and application of the model-based monomer feeding strategies (MMFS) on precise production of polymer chains. With the MMFS method, a series of polymer products with predesigned copolymer composition distributions and chain topologies are successfully synthesized by semi-batch-controlled radical polymerization. Extending MMFS to heterogeneous systems and to continuous polymerization operations are encouraged in future research.

  3. Full Papers

    1. Novel SiO2-Supported Chromium Oxide(Cr)/Vanadium Oxide(V) Bimetallic Catalysts for Production of Bimodal Polyethylene

      Ruihua Cheng, Xin Xue, Weiwei Liu, Ning Zhao, Xuelian He, Zhen Liu and Boping Liu

      Article first published online: 12 MAY 2015 | DOI: 10.1002/mren.201400072

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      A series of SiO2-supported Cr–V bimetallic oxides catalysts were successfully synthesized through introduction of vanadium oxide into the traditional Phillips CrOx/SiO2 catalyst. Using these Cr/V bimetallic catalysts, one-pot synthesis of polyethylene and ethylene/1-hexene copolymers with bimodal MWD and improved short chain branch distribution together with enhancement of catalytic activity was achieved.

    2. Kinetics and Modeling of Ring-Opening Copolymerization of l-Lactide and ε-Caprolactone

      Feiyin Weng, Xiaohui Li, Yanjiao Wang, Wen-Jun Wang and Steven J. Severtson

      Article first published online: 27 APR 2015 | DOI: 10.1002/mren.201500009

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      A model for ring-opening copolymerization of l-lactide and ε-caprolactone based on coordination insertion mechanism, considering diffusion control in propagation and transesterification reactions is developed. It is successfully applied to predict monomer conversion, molecular weight and distribution, and cumulative polymer composition for copolymers with variable compositions as well as variable chain lengths.

    3. A Study on a Prepolymerization Process of Aromatic-Contained Polyamide Copolymers PA(66-co-6T) via One-Step Polycondensation

      Cai-Liang Zhang, Li Wan, Xue-Ping Gu and Lian-Fang Feng

      Article first published online: 16 APR 2015 | DOI: 10.1002/mren.201500006

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      A facile one-step polycondensation approach to prepare a prepolymer of aromatic-contained polyamide using terephthalic acid (PTA), adipic acid (ADA), hexamethylenediamine (HMDA) as raw materials was explored. The prepolymerization process was divided into four stages: formation of nylon salt, temperature rising, polycondensation, and venting.

    4. Modeling of Highly Branched Water-Soluble Polymers with Applications to Drug Delivery Model Extensions and Validation

      Seung Yeon Kim, Robert Van Dyke, Kai Chang, Lakeshia J. Taite and Francis Joseph Schork

      Article first published online: 7 APR 2015 | DOI: 10.1002/mren.201500010

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      The use of controlled polymerization of a polymer exhibiting a lower critical solution temperature and a polymerizable chain transfer agent to produce highly branched polymer for is explored via mathematical modeling. The application of such polymers is in drug delivery. The model is developed and compared with experimental data.

    5. A Novel Approval for Degradation of Polybutadiene and Synthesis of Diene-Based Telechelic Oligomers via Olefin Cross Metathesis

      Bin Jiang, Tian Wei, Ting-Ting Zou, Gary L. Rempel and Qin-Ming Pan

      Article first published online: 1 APR 2015 | DOI: 10.1002/mren.201500004

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      Synthesis of well-defined functionalized telechelic oligomers containing only a few butadiene repeating units is accomplished via metathetic degradation of polybutadiene in the presence of Grubbs second generation catalyst with selected monomers as chain transfer agents. The structures and compositions of metathesis products are acquired using 1H-NMR and GC-MS analysis.

    6. Modeling of the Dehydration Process Coupled with Solid-State Polymerization in Nylon 6 Drying Column

      Guojian Sun, Chunxi Qin, Zhenhao Xi, Zhimei Xu, Weizhen Sun and Ling Zhao

      Article first published online: 1 APR 2015 | DOI: 10.1002/mren.201400062

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      Nylon 6 drying is a gas–solid countercurrent process, containing both mass/heat transfer and solid-state polymerization (SSP) at relative low temperatures. In this paper, an integrated model combining the mass/heat transfer and polymerization reaction has been presented for Nylon 6 drying process. The influences of operation conditions on the moisture content and the degree of polymerization distribution profiles in industrial drying column have been discussed.

  4. Reviews

    1. Encapsulation of PV Modules Using Ethylene Vinyl Acetate Copolymer as the Encapsulant

      Shan Jiang, Kemin Wang, Hongwen Zhang, Yonghong Ding and Qiang Yu

      Article first published online: 27 MAR 2015 | DOI: 10.1002/mren.201400065

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      This article pays special attention to research work on improving the performance of EVA encapsulation films of photovoltaic (PV) modules, including the aging resistance, adhesive strength, and energy conversion efficiency. β-Diketone macromolecular complexes are synthesized and doped into EVA film to increase the photovoltaic conversion efficiency and service life of EVA films.

  5. Feature Articles

    1. New Chemistries and Technologies Derived from a Common Reaction of α-Methylstyrene at 61 °C

      Yuhong Ma, Shan Jiang, Shujun Liang and Wantai Yang

      Article first published online: 25 MAR 2015 | DOI: 10.1002/mren.201400059

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      Free radical copolymerizations of styrene and (meth)acrylates with α-methylstyrene as the comonomer show that the molecular weights of the copolymers increase with the monomer conversion. The copolymers are able to generate chain free radicals when heated above 90 °C. These chain radicals have been applied to initiate vinyl monomers to prepare block and functional polymers. In addition, these chain radicals can act as in situ compatibilizers by forming graft polymers and can also modify MWCNTs by a grafting-onto mechanism.

    2. Polytrimethylene Terephthalate: An Example of an Industrial Polymer Platform Development in China

      Qiongdan Xie, Xilong Hu, Tengjiao Hu, Pan Xiao, Youyong Xu and Kenneth W. Leffew

      Article first published online: 24 MAR 2015 | DOI: 10.1002/mren.201400070

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      This short review introduces the industrial polymer platform of polytrimethylene terephthalate (Sorona) within DuPont China Research and Development Center founded in 2005. The R&D competencies and some of the research content on Sorona are briefly introduced in this paper. This platform continues to develop new applications for Sorona and provides technical support to the Chinese market for Sorona.

  6. Full Papers

    1. Tailor Made Products by Smart Processes

      Thomas Bott, Wolfgang Gerlinger and Johannes Barth

      Article first published online: 17 MAR 2015 | DOI: 10.1002/mren.201400069

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      Tailor made products by smart processes. From our industrial perspective, successful product development in the future will include more modeling starting at understanding of structure property relationships of a desired application rather than at synthesizing and screening new structures. Globalization in research will play an important role. BASF, being recognized as one of the leading employers in China, will be continuing to expand its research and development activities in Asia as well as in America in order to participate in regional innovation processes.

    2. Monte Carlo Modeling of Free Radical Polymerization in Microflow Reactors

      Zehui Gao and Junpo He

      Article first published online: 13 MAR 2015 | DOI: 10.1002/mren.201400061

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      Monte Carlo simulation is developed to model free radical polymerization in microflow reactor. The algorithm combines the stochastic process of the reactions with diffusion and flow, and is able to predict the polymerization rate, molecular weight, PDI, and copolymer sequence as a function of reaction time.

    3. Correlating Cobalt Net Charges with Catalytic Activities of the 2-(Benzimidazolyl)-6-(1-aryliminoethyl)pyridylcobalt Complexes toward Ethylene Polymerization

      Wenhong Yang, Yan Chen and Wen-Hua Sun

      Article first published online: 3 MAR 2015 | DOI: 10.1002/mren.201400064

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      DFT-QEq method was applied to study the catalytic activities for the series of 2-(Benzimidazolyl)-6-(1-aryliminoethyl)pyridyl cobalt complex pre-catalysts, which are analogues to iron systems reported previously. Good correlations were presented between experimental activities and calculated effective net charges. Comparisons with iron analogues indicated the variations of net charge on metal atoms are the same as a function of complex.

    4. Modeling of the ATRcoP Processes of Methyl Methacrylate and 2-(Trimethylsilyl) Ethyl Methacrylate in Continuous Reactors: From CSTR to PFR

      Wei Wang, Yin-Ning Zhou and Zheng-Hong Luo

      Article first published online: 26 FEB 2015 | DOI: 10.1002/mren.201400056

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      A tubular reactor model was developed to describe the ATRcoP of methyl methacrylate (MMA) and 2-(trimethylsilyl) ethyl methacrylate (HEMA-TMS) under different axial dispersions. The main ATRcoP behaviors and polymer micro-characteristics were obtained. Finally, the effects of flow patterns (including the CSTR and PFR modes) in different reactors on the ATRcoP characteristics were investigated using the model.

    5. Neodymium-Based Catalyst for the Coordination Polymerization of Butadiene: From Fundamental Research to Industrial Application

      Han Zhu, Ping Chen, Chang-Feng Yang and Yi-Xian Wu

      Article first published online: 19 FEB 2015 | DOI: 10.1002/mren.201400063

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      The neodymium-based catalyst system with high catalytic activity and stereoselectivity to butadiene polymerization was developed to produce polybutadiene with extremely high cis-1,4 configuration. The innovation technology has been achieved from fundamental research to industrial application.

    6. Comparison of RAFT Ab Initio Emulsion Polymerization of Methyl Methacrylate and Styrene Mediated by Oligo(methacrylic acid-b-methyl methacrylate) Trithiocarbonate Surfactant

      Yue Zhu, Shangyu Bi, Xiang Gao and Yingwu Luo

      Article first published online: 19 FEB 2015 | DOI: 10.1002/mren.201400058

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      MMA RAFT emulsion polymerization using oligo(MAA41-b-MMA8) RAFT as surfactant is conducted by comparison with the classical styrene systems. In MMA system, the coagulum-free latexes of high living polymers were achieved at 80 °C and low KPS concentrations, together with a broader final PDI than that in styrene system. The poorer polymerization performance of MMA RAFT emulsion polymerization is explained by the combination of the homogeneous nucleation mode of particles and the slow transportation rate of the oligomeric RAFT agent molecules from micelles to new-born particles.

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