@article{AlNajiSchlaadAntonietti2020,
  author    = {Al-Naji, Majd and Schlaad, Helmut and Antonietti, Markus},
  title     = {New (and old) monomers from biorefineries to make polymer chemistry more sustainable},
  series = {Macromolecular rapid communications},
  volume    = {42},
  journal   = {Macromolecular rapid communications},
  number    = {3},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1022-1336},
  doi       = {10.1002/marc.202000485},
  pages     = {11},
  year      = {2020},
  abstract  = {This opinion article describes recent approaches to use the "biorefinery" concept to lower the carbon footprint of typical mass polymers, by replacing parts of the fossil monomers with similar or even the same monomer made from regrowing dendritic biomass. Herein, the new and green catalytic synthetic routes are for lactic acid (LA), isosorbide (IS), 2,5-furandicarboxylic acid (FDCA), and p-xylene (pXL). Furthermore, the synthesis of two unconventional lignocellulosic biomass derivable monomers, i.e., alpha-methylene-gamma-valerolactone (MeGVL) and levoglucosenol (LG), are presented. All those have the potential to enter in a cost-effective way, also the mass market and thereby recover lost areas for polymer materials. The differences of catalytic unit operations of the biorefinery are also discussed and the challenges that must be addressed along the synthesis path of each monomers.},
  language  = {en}
}
@misc{AlNajiSchlaadAntonietti2020,
  author    = {Al-Naji, Majd and Schlaad, Helmut and Antonietti, Markus},
  title     = {New (and old) monomers from biorefineries to make polymer chemistry more sustainable},
  series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {3},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-57061},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-570614},
  pages     = {13},
  year      = {2020},
  abstract  = {This opinion article describes recent approaches to use the "biorefinery" concept to lower the carbon footprint of typical mass polymers, by replacing parts of the fossil monomers with similar or even the same monomer made from regrowing dendritic biomass. Herein, the new and green catalytic synthetic routes are for lactic acid (LA), isosorbide (IS), 2,5-furandicarboxylic acid (FDCA), and p-xylene (pXL). Furthermore, the synthesis of two unconventional lignocellulosic biomass derivable monomers, i.e., alpha-methylene-gamma-valerolactone (MeGVL) and levoglucosenol (LG), are presented. All those have the potential to enter in a cost-effective way, also the mass market and thereby recover lost areas for polymer materials. The differences of catalytic unit operations of the biorefinery are also discussed and the challenges that must be addressed along the synthesis path of each monomers.},
  language  = {en}
}
@article{BehrendtHessLehmannetal.2019,
  author    = {Behrendt, Felix Nicolas and Hess, Andreas and Lehmann, Max and Schmidt, Bernd and Schlaad, Helmut},
  title     = {Polymerization of cystine-derived monomers},
  series = {Polymer Chemistry},
  volume    = {10},
  journal   = {Polymer Chemistry},
  number    = {13},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {1759-9954},
  doi       = {10.1039/c9py00118b},
  pages     = {1636 -- 1641},
  year      = {2019},
  abstract  = {Cystine was used as a platform chemical to prepare cyclic and acyclic monomers for entropy-driven ringopening polymerization (ED-ROMP) via olefin or disulfide metathesis and for step-growth polymerization. The olefin ED-ROMP of an olefin/disulfide containing 16-atom macrocycle using the 3rd generation Grubbs catalyst was examined in greater detail. Kinetic studies revealed that the catalyst turned inactive during the polymerization, which limited the achievable (apparent) polymer molar mass to similar to 70 kg mol(-1). Such limitation could be overcome with the disulfide ED-ROMP of the same macrocycle to yield polymers with molar masses of up to 180 kg mol(-1). The step-growth polymerizations of acyclic diene and dithiol monomers via olefin metathesis or oxidation were far less effective and yielded just low molar mass polymers or oligomers; photopolymerization of a thiol-ene monomer produced a polyester with a molar mass of 35 kg mol(-1).},
  language  = {en}
}
@misc{BehrendtSchlaad2016,
  author    = {Behrendt, Felix Nicolas and Schlaad, Helmut},
  title     = {Metathesis polymerization of cystine-based macrocycles},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-395080},
  pages     = {4},
  year      = {2016},
  abstract  = {Macrocycles based on L-cystine were synthesized by ring-closing metathesis (RCM) and subsequently polymerized by entropy-driven ring-opening metathesis polymerization (ED-ROMP). Monomer conversion reached ∼80\% in equilibrium and the produced poly(ester-amine-disulfide-alkene)s exhibited apparent molar masses (Mappw) of up to 80 kDa and dispersities (Đ) of ∼2. The polymers can be further functionalized with acid anhydrides and degraded by reductive cleavage of the main-chain disulfide.},
  language  = {en}
}
@article{BehrendtSchlaad2018,
  author    = {Behrendt, Felix Nicolas and Schlaad, Helmut},
  title     = {Entropy-Driven Ring-Opening Disulfide Metathesis Polymerization for the Synthesis of Functional Poly(disulfide)s},
  series = {Macromolecular rapid communications},
  volume    = {39},
  journal   = {Macromolecular rapid communications},
  number    = {6},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1022-1336},
  doi       = {10.1002/marc.201700735},
  pages     = {4},
  year      = {2018},
  abstract  = {Metal-free entropy-driven disulfide metathesis polymerization of unsaturated L-cystine based macrocycles produces high-molar-mass heterofunctional poly(disulfide)s, i.e., poly(ester-disulfide-alkene) and poly(amide-disulfide-alkene); M-w(app) = 44-60 kDa, (sic) > 1.7. The polymerization is fast and reaches equilibrium within 1-5 minutes (monomer conversion 70-90\%) in polar aprotic solvents such as N,N-dimethylacetamide, dimethylsulfoxide, or y-valerolactone. Thiol-terminated polymers are stable in bulk or when dissolved in weakly polar solvents, but rapidly depolymerize in dilute polar solution.},
  language  = {en}
}
@article{BehrendtSchlaad2017,
  author    = {Behrendt, Felix Nicolas and Schlaad, Helmut},
  title     = {Metathesis polymerization of cystine-based macrocycles},
  series = {Polymer Chemistry},
  volume    = {8},
  journal   = {Polymer Chemistry},
  number    = {2},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {1759-9954},
  doi       = {10.1039/c6py01864e},
  pages     = {366 -- 369},
  year      = {2017},
  abstract  = {Macrocycles based on L-cystine were synthesized by ring-closing metathesis (RCM) and subsequently polymerized by entropy-driven ring-opening metathesis polymerization (ED-ROMP). Monomer conversion reached similar to 80\% in equilibrium and the produced poly (ester-amine-disulfide-alkene)s exhibited apparent molar masses (M-w(app)) of up to 80 kDa and dispersities (D) of similar to 2. The polymers can be further functionalized with acid anhydrides and degraded by reductive cleavage of the main-chain disulfide.},
  language  = {en}
}
@article{BogomolovaSeckerKoetzetal.2017,
  author    = {Bogomolova, Anna and Secker, Christian and Koetz, Joachim and Schlaad, Helmut},
  title     = {Thermo-induced multistep assembly of double-hydrophilic block copolypeptoids in water},
  series = {Colloid and polymer science : official journal of the Kolloid-Gesellschaft},
  volume    = {295},
  journal   = {Colloid and polymer science : official journal of the Kolloid-Gesellschaft},
  publisher = {Springer},
  address   = {New York},
  issn      = {0303-402X},
  doi       = {10.1007/s00396-017-4044-6},
  pages     = {1305 -- 1312},
  year      = {2017},
  abstract  = {The aqueous solution behavior of thermoresponsive-hydrophilic block copolypeptoids, i.e., poly(N-(n-propyl)glycine) (x) -block-poly(N-methylglycine) (y) (x = 70; y = 23, 42, 76), in the temperature range of 20-45 A degrees C is studied. Turbidimetric analyses of the 0.1 wt\% aqueous solutions reveal two cloud points at T (cp)similar to 30 and 45 A degrees C and a clearing point in between at T (cl)similar to 42 A degrees C. Temperature-dependent dynamic light scattering (DLS) suggest that right above the first collapse temperature, single polymer molecules assemble into large structures which upon further heating, i.e., at the clearing point temperature, disassemble into micelle-like structures. Upon further heating, the aggregates start to grow again in size, as recognized by the second cloud point, through a crystallization process.},
  language  = {en}
}
@article{BrosnanSchlaad2014,
  author    = {Brosnan, Sarah M. and Schlaad, Helmut},
  title     = {Modification of polypeptide materials by Thiol-X chemistry},
  series = {Polymer : the international journal for the science and technology of polymers},
  volume    = {55},
  journal   = {Polymer : the international journal for the science and technology of polymers},
  number    = {22},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0032-3861},
  doi       = {10.1016/j.polymer.2014.08.067},
  pages     = {5511 -- 5516},
  year      = {2014},
  abstract  = {Thiol-X chemistry has proven to be a valuable toolbox for modification of peptides, proteins, monomers, and polymers. Recently, this has become especially true for the modification of polypeptides (monomers or polymers), which has resulted in a plethora of novel polymers and materials. With this in mind, this highlight focuses on the recent literature concerning the modification of polypeptides by the use of thiol-X chemistry, in particular to synthetic polypeptides either at the monomer or polymer stage modified by thiol-ene, -Michael addition, and -yne chemistries. (C) 2014 Published by Elsevier Ltd.},
  language  = {en}
}
@article{BrosnanSchlaadAntonietti2015,
  author    = {Brosnan, Sarah M. and Schlaad, Helmut and Antonietti, Markus},
  title     = {Aqueous Self-Assembly of Purely Hydrophilic Block Copolymers into Giant Vesicles},
  series = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition},
  volume    = {54},
  journal   = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition},
  number    = {33},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1433-7851},
  doi       = {10.1002/anie.201502100},
  pages     = {9715 -- 9718},
  year      = {2015},
  abstract  = {Self-assembly of macromolecules is fundamental to life itself, and historically, these systems have been primitively mimicked by the development of amphiphilic systems, driven by the hydrophobic effect. Herein, we demonstrate that self-assembly of purely hydrophilic systems can be readily achieved with similar ease and success. We have synthesized double hydrophilic block copolymers from polysaccharides and poly(ethylene oxide) or poly(sarcosine) to yield high molar mass diblock copolymers through oxime chemistry. These hydrophilic materials can easily assemble into nanosized (<500nm) and microsized (>5m) polymeric vesicles depending on concentration and diblock composition. Because of the solely hydrophilic nature of these materials, we expect them to be extraordinarily water permeable systems that would be well suited for use as cellular mimics.},
  language  = {en}
}
@article{CasseShkilnyyLindersetal.2012,
  author    = {Casse, Olivier and Shkilnyy, Andriy and Linders, J{\"u}rgen and Mayer, Christian and H{\"a}ussinger, Daniel and V{\"o}lkel, Antje and Th{\"u}nemann, Andreas F. and Dimova, Rumiana and C{\"o}lfen, Helmut and Meier, Wolfgang P. and Schlaad, Helmut and Taubert, Andreas},
  title     = {Solution behavior of double-hydrophilic block copolymers in dilute aqueous solution},
  series = {Macromolecules : a publication of the American Chemical Society},
  volume    = {45},
  journal   = {Macromolecules : a publication of the American Chemical Society},
  number    = {11},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0024-9297},
  doi       = {10.1021/ma300621g},
  pages     = {4772 -- 4777},
  year      = {2012},
  abstract  = {The self-assembly of double-hydrophilic poly(ethylene oxide)-poly(2-methyl-2-oxazoline) diblock copolymers in water has been studied. Isothermal titration calorimetry, small-angle X-ray scattering, and analytical ultracentrifugation suggest that only single polymer chains are present in solution. In contrast, light scattering and transmission electron microscopy detect aggregates with radii of ca. 100 nm. Pulsed field gradient NMR spectroscopy confirms the presence of aggregates, although only 2\% of the polymer chains undergo aggregation. Water uptake experiments indicate differences in the hydrophilicity of the two blocks, which is believed to be the origin of the unexpected aggregation behavior (in accordance with an earlier study by Ke et al. [Macromolecules 2009, 42, 5339-5344]). The data therefore suggest that even in double-hydrophilic block copolymers, differences in hydrophilicity are sufficient to drive polymer aggregation, a phenomenon that has largely been overlooked or ignored so far.},
  language  = {en}
}
@article{ChandranDoldBuvignieretal.2015,
  author    = {Chandran, Sivasurender and Dold, Stefanie and Buvignier, Amaury and Krannig, Kai-Steffen and Schlaad, Helmut and Reiter, G{\"u}nter and Reiter, Renate},
  title     = {Tuning Morphologies of Langmuir Polymer Films Through Controlled Relaxations of Non-Equilibrium States},
  series = {Langmuir},
  volume    = {31},
  journal   = {Langmuir},
  number    = {23},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0743-7463},
  doi       = {10.1021/acs.langmuir.5b01212},
  pages     = {6426 -- 6435},
  year      = {2015},
  abstract  = {Langmuir polymers films (LPFs) frequently form non-equilibrium states which are manifested in a decay of the surface pressure with time when the system is allowed to relax. Monitoring and manipulating the temporal evolution of these relaxations experimentally helps to shed light on the associated molecular reorganization processes. We present a systematic study based on different compression protocols and show how these reorganization processes impact the morphology of LPFs of poly(gamma-benzyl-L-glutamate) (PBLG); visualized by means of atomic force microscopy. Upon continuous compression, a fibrillar morphology was formed with a surface decorated by squeezed-out islands. By contrast, stepwise compression promoted the formation of a fibrillar network with a bimodal distribution of fibril diameters, caused by merging of fibrils. Finally, isobaric compression induced in-plane compaction of the monolayer. We correlate these morphological observations with the kinetics of the corresponding relaxations, described best by a sum of two exponential functions with different time scales representing two molecular processes. We discuss the observed kinetics and the resulting morphologies in the context of nucleation and growth, characteristic for first-order phase transitions. Our results demonstrate that the preparation conditions of LPFs have tremendous impact on ordering of the molecules and hence various macroscopic properties of such films.},
  language  = {en}
}
@article{ChenSongZhaoetal.2018,
  author    = {Chen, Ye and Song, Qilei and Zhao, Junpeng and Gong, Xiangjun and Schlaad, Helmut and Zhang, Guangzhao},
  title     = {Betulin-Constituted multiblock amphiphiles for broad-spectrum protein resistance},
  series = {ACS applied materials \& interfaces},
  volume    = {10},
  journal   = {ACS applied materials \& interfaces},
  number    = {7},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1944-8244},
  doi       = {10.1021/acsami.7b16255},
  pages     = {6593 -- 6600},
  year      = {2018},
  abstract  = {Multiblock-like amphiphilic polyurethanes constituted by poly(ethylene oxide) and biosourced betulin are designed for antifouling and synthesized by a convenient organocatalytic route comprising tandem chain-growth and step-growth polymerizations. The doping density of betulin (D-B) in the polymer chain structure is readily varied by a mixed-initiator strategy. The spin-coated polymer films exhibit unique nanophase separation and protein resistance behaviors. Higher D-B leads to enhanced surface hydrophobicity and, unexpectedly, improved protein resistance. It is found that the surface holds molecular-level heterogeneity when D-B is substantially high due to restricted phase separation; therefore, broad-spectrum protein resistance is achieved despite considerable surface hydrophobicity. As D-B decreases, the distance between adjacent betulin units increases so that hydrophobic nanodomains are formed, which provide enough landing areas for relatively small-sized proteins to adsorb on the surface.},
  language  = {en}
}
@misc{DaniTaeuberZhangetal.2018,
  author    = {Dani, Alessandro and Taeuber, Karoline and Zhang, Weiyi and Schlaad, Helmut and Yuan, Jiayin},
  title     = {Stable covalently photo-cross-linked porous poly(ionic liquid) membrane with gradient pore size},
  series = {Abstracts of papers : joint conference / The Chemical Institute of Cananda, CIC, American Chemical Society, ACS},
  volume    = {256},
  journal   = {Abstracts of papers : joint conference / The Chemical Institute of Cananda, CIC, American Chemical Society, ACS},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0065-7727},
  pages     = {1},
  year      = {2018},
  abstract  = {Porous polyelectrolyte membranes stable in a highly ionic environment are obtained by covalent crosslinking of an imidazolium-based poly(ionic liquid). The crosslinking reaction involves the UV light-induced thiol-ene (click) chemistry, and the phase separation, occurring during the crosslinking step, generates a fully interconnected porous structure in the membrane. The porosity is on the order of the micrometer scale and the membrane shows a gradient of pore size across the membrane cross-section. The membrane can separate polystyrene latex particles of different size and undergoes actuation in contact with acetone due to the asymmetric porous structure.},
  language  = {en}
}
@article{DaniTauberZhangetal.2017,
  author    = {Dani, Alessandro and Tauber, Karoline and Zhang, Weiyi and Schlaad, Helmut and Yuan, Jiayin},
  title     = {Stable Covalently Photo-Crosslinked Poly(Ionic Liquid) Membrane with Gradient Pore Size},
  series = {Macromolecular rapid communications},
  volume    = {38},
  journal   = {Macromolecular rapid communications},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1022-1336},
  doi       = {10.1002/marc.201700167},
  pages     = {4},
  year      = {2017},
  abstract  = {Porous polyelectrolyte membranes stable in a highly ionic environment are obtained by covalent crosslinking of an imidazolium-based poly(ionic liquid). The crosslinking reaction involves the UV light-induced thiol-ene (click) chemistry, and the phase separation, occurring during the crosslinking step, generates a fully interconnected porous structure in the membrane. The porosity is on the order of the micrometer scale and the membrane shows a gradient of pore size across the membrane cross-section. The membrane can separate polystyrene latex particles of different size and undergoes actuation in contact with acetone due to the asymmetric porous structure.},
  language  = {en}
}
@article{DasElTawargyKhechineetal.2019,
  author    = {Das, Abhijna and El-Tawargy, Ahmed S. and Khechine, Emna and Noack, Sebastian and Schlaad, Helmut and Reiter, G{\"u}nter and Reiter, Renate},
  title     = {Controlling Nucleation in Quasi-Two-Dimensional Langmuir Poly(L-lactide) Films through Variation of the Rate of Compression},
  series = {Langmuir},
  volume    = {35},
  journal   = {Langmuir},
  number    = {18},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0743-7463},
  doi       = {10.1021/acs.langmuir.9b00619},
  pages     = {6129 -- 6136},
  year      = {2019},
  abstract  = {We studied morphological changes in a quasi-two-dimensional Langmuir film of low molar mass poly(L-lactide) upon increasing the surface density, starting from randomly distributed molecules to a homogeneous monolayer of closely packed molecules, followed by nucleation and growth of mesoscopic, three-dimensional clusters from an overcompressed monolayer. The corresponding nucleation density of mesoscopic clusters within the monolayer can be tailored through variation of the rate of compression. For a given surface density and temperature, the nucleation probability was found to increase linearly with the rate of compression, allowing to adjust the density of mesoscopic clusters over nearly 2 orders magnitude.},
  language  = {en}
}
@article{DasNoackSchlaadetal.2020,
  author    = {Das, Abhijna and Noack, Sebastian and Schlaad, Helmut and Reiter, G{\"u}nter and Reiter, Renate},
  title     = {Exploring pathways to equilibrate Langmuir polymer films},
  series = {Langmuir},
  volume    = {36},
  journal   = {Langmuir},
  number    = {28},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0743-7463},
  doi       = {10.1021/acs.langmuir.0c01268},
  pages     = {8184 -- 8192},
  year      = {2020},
  abstract  = {Focusing on the phase-coexistence region in Langmuir films of poly(L-lactide), we investigated changes in nonequilibrated morphologies and the corresponding features of the isotherms induced by different experimental pathways of lateral compression and expansion. In this coexistence region, the surface pressure II was larger than the expected equilibrium value and was found to increase upon compression, i.e., exhibited a nonhorizontal plateau. As shown earlier by using microscopic techniques [Langmuir 2019, 35, 6129-6136], in this plateau region, well-ordered mesoscopic clusters coexisted with a surrounding matrix phase. We succeeded in reducing Pi either by slowing down the rate of compression or through increasing the waiting time after stopping the movement of the barriers, which allowed for relaxations in the coexistence region. Intriguingly, the most significant pressure reduction was observed when recompressing a film that had already been compressed and expanded, if the recompression was started from an area value smaller than the one anticipated for the onset of the coexistence region. This observation suggests a "self-seeding" behavior, i.e., pre-existing nuclei allowed to circumvent the nucleation step. The decrease in Pi was accompanied by a transformation of the initially formed metastable mesoscopic clusters into a thermodynamically favored filamentary morphology. Our results demonstrate that it is practically impossible to obtain fully equilibrated coexisting phases in a Langmuir polymer film, neither under conditions of extremely slow continuous compression nor for long waiting times at a constant area in the coexistence region which allow for reorganization.},
  language  = {en}
}
@article{DebsharmaBehrendtLaschewskyetal.2019,
  author    = {Debsharma, Tapas and Behrendt, Felix Nicolas and Laschewsky, Andre and Schlaad, Helmut},
  title     = {Ring-opening metathesis polymerization of biomass-derived levoglucosenol},
  series = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker},
  volume    = {58},
  journal   = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker},
  number    = {20},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1433-7851},
  doi       = {10.1002/anie.201814501},
  pages     = {6718 -- 6721},
  year      = {2019},
  abstract  = {The readily available cellulose-derived bicyclic compound levoglucosenol was polymerized through ring-opening metathesis polymerization (ROMP) to yield polylevoglucosenol as a novel type of biomass-derived thermoplastic polyacetal, which, unlike polysaccharides, contains cyclic as well as linear segments in its main chain. High-molar-mass polyacetals with apparent weight-average molar masses of up to 100kgmol(-1) and dispersities of approximately 2 were produced despite the non-living/controlled character of the polymerization due to irreversible deactivation or termination of the catalyst/active chain ends. The resulting highly functionalized polyacetals are glassy in bulk with a glass transition temperature of around 100 degrees C. In analogy to polysaccharides, polylevoglucosenol degrades slowly in an acidic environment.},
  language  = {en}
}
@article{DebsharmaSchmidtLaschewskyetal.2021,
  author    = {Debsharma, Tapas and Schmidt, Bernd and Laschewsky, Andre and Schlaad, Helmut},
  title     = {Ring-opening metathesis polymerization of unsaturated carbohydrate derivatives},
  series = {Macromolecules : a publication of the American Chemical Society},
  volume    = {54},
  journal   = {Macromolecules : a publication of the American Chemical Society},
  number    = {6},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0024-9297},
  doi       = {10.1021/acs.macromol.0c02821},
  pages     = {2720 -- 2728},
  year      = {2021},
  abstract  = {A series of biomass-derived levoglucosenyl alkyl ethers (alkyl = methyl, ethyl, n-propyl, isopropyl, and n-butyl) were synthesized and polymerized by ring-opening olefin metathesis polymerization using the Grubbs catalyst C793 at room temperature. Polymerizations were successfully performed in conventional solvents such as 1,4-dioxane and dichloromethane as well as in polar aprotic "green" solvents such as 2-methyltetrahydrofuran, dihydrolevoglucosenone (Cyrene), and ethyl acetate. The prepared polyacetals with degrees of polymerization of similar to 100 exhibit Schulz-Flory-type molar mass distributions and are thermoplastic materials with rather low glass transition temperatures in the range of 43-0 degrees C depending on the length of the alkyl substituent. Kinetic studies revealed that the polymerization proceeded rapidly to a steady state with a certain minimum monomer concentration threshold. When the steady state was reached, just about half of the [Ru] catalyst had been effective to initiate the polymerization, indicating that the initiation step was a slow process. The remaining catalyst was still active and did no longer react with monomers but with in-chain double bonds, cutting the formed polymer chains into shorter fragments. In the long term, all catalyst was consumed and propagating [Ru] chain ends were deactivated by the elimination of [Ru] from the chain ends to form inactive chains with terminal aldehyde groups.},
  language  = {en}
}
@article{DemirelGunerVerbraekenetal.2016,
  author    = {Demirel, A. Levent and Guner, Pinar Tatar and Verbraeken, Bart and Schlaad, Helmut and Schubert, Ulrich S. and Hoogenboom, Richard},
  title     = {Revisiting the Crystallization of Poly(2-alkyl-2-oxazoline)s},
  series = {Journal of polymer science : B, Polymer physics},
  volume    = {54},
  journal   = {Journal of polymer science : B, Polymer physics},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0887-6266},
  doi       = {10.1002/polb.23967},
  pages     = {721 -- 729},
  year      = {2016},
  abstract  = {Poly(2-alkyl-2-oxazoline)s (PAOx) exhibit different crystallization behavior depending on the length of the alkyl side chain. PAOx having methyl, ethyl, or propyl side chains do not show any bulk crystallization. Crystallization in the heating cycle, that is, cold crystallization, is observed for PAOx with butyl and pentyl side chains. For PAOx with longer alkyl side chains crystallization occurs in the cooling cycle. The different crystallization behavior is attributed to the different polymer chain mobility in line with the glass transition temperature (T-g) dependency on alkyl side chain length. The decrease in chain mobility with decreasing alkyl side chain length hinders the relaxation of the polymer backbone to the thermodynamic equilibrium crystalline structure. Double melting behavior is observed for PButOx and PiPropOx which is explained by the melt-recrystallization mechanism. Isothermal crystallization experiments of PButOx between 60 and 90 degrees C and PiPropOx between 90 and 150 degrees C show that PAOx can crystallize in bulk when enough time is given. The decrease of Tg and the corresponding increase in chain mobility at T > T-g with increasing alkyl side chain length can be attributed to an increasing distance between the polymer backbones and thus decreasing average strength of amide dipole interactions. (C) 2015 Wiley Periodicals, Inc.},
  language  = {en}
}
@article{DevRoeslerSchlaad2021,
  author    = {Dev, Akhil and R{\"o}sler, Alexander and Schlaad, Helmut},
  title     = {Limonene as a renewable unsaturated hydrocarbon solvent for living anionic polymerization of β-myrcene},
  series = {Polymer chemistry},
  volume    = {12},
  journal   = {Polymer chemistry},
  number    = {21},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {1759-9954},
  doi       = {10.1039/d1py00570g},
  pages     = {3084 -- 3087},
  year      = {2021},
  abstract  = {The acyclic monoterpene beta-myrcene is polymerized by anionic polymerization at room temperature using sec-butyllithium as the initiator and the cyclic monoterpene DL-limonene as an unsaturated hydrocarbon solvent. The polymerization is a living process and allows production of polymyrcenes with narrow molar mass distribution ((sic) similar to 1.06) and high content of 1,4 units (similar to 90\%) as well as block copolymers.},
  language  = {en}
}