Polymer Chemistry Blog

In their paper, Gao , Yang and co-workers grafted β-cyclodextrins (β-CDs) onto star-shaped poly(glycidyl methacrylate)s (S5-PGMAs) with a straightforward and efficient ring-opening addition of amine groups to result in PGMA–β-CDs, which not only possess good water-solubility and biocompatibility, but also can serve as polymeric supramolecular hosts to form inclusion complexes with suitable guests. They can be easily assembled on the surface of azobenzene-functionalized MSNs via host–guest interactions to obtain MSN@PGMA–β-CD hybrid nanoparticles. The experimental results showed that these types of inorganic–organic hybrid mesoporous nanocomposites possess good cargo encapsulation and release properties, as compared with the simple supramolecular nanovalves with β-CD itself as the gating component, upon activation by light, temperature variation, and competitive binding agents. In addition, the extremely low cytotoxicity of the nanocomposites demonstrated by MTT assay can further broaden their applications in controlled drug release.

Stimuli-responsive biocompatible nanovalves based on β-cyclodextrin modified poly(glycidyl methacrylate) by Qing-Lan Li, Lizhi Wang, Xi-Long Qiu, Yu-Long Sun, Pei-Xi Wang, Yu Liu, Feng Li, Ai-Di Qi, Hui Gao and Ying-Wei Yang Polym. Chem. 2014, 5, 3389-3395.

Julien Nicolas is a web-writer and advisory board member for Polymer Chemistry. He currently works at Univ. Paris-Sud (FR) as a CNRS researcher.

In this article, Kamigaito and co-workers cationically polymerized (−)-β-pinene, a major constituent of pine tree oil,  to generate a high-molecular-weight polymer that were subsequently hydrogenated via metal catalysts to give a high-performance, bio-based cycloolefin polymer with an alicyclic backbone. To obtain the high-molecular-weight polymer, the controlled/living cationic polymerization of (−)-β-pinene was investigated by an initiating system, consisting of a protonic acid, a Lewis acid, and an added base, along with an incremental monomer addition technique. These reactions could be performed even at relatively large scales to produce several hundred grams of the polymer, which can be then processed through injection-molding. The synthesized bio-based cycloolefin polymers demonstrated promising potential properties as high performance optical plastics with good processability, low density, high optical transparency, low birefringence, non-hygroscopicity, high mechanical strength, and excellent thermal properties.

Sustainable cycloolefin polymer from pine tree oil for optoelectronics material: living cationic polymerization of β-pinene and catalytic hydrogenation of high-molecular-weight hydrogenated poly(β-pinene) by Kotaro Satoh, Atsuhiro Nakahara, Kazunori Mukunoki, Hiroko Sugiyama, Hiromu Saito and Masami Kamigaito Polym. Chem. 2014, 5, 3222-3230.

Julien Nicolas is a web-writer and advisory board member for Polymer Chemistry. He currently works at Univ. Paris-Sud (FR) as a CNRS researcher.

To overcome these drawbacks, Berthelot and co-workers proposed here an innovative process, based on VUV irradiation, which proved efficient not only for surface modification, but also for the bulk modification of industrially relevant polymers such as β-polyvinylidene fluoride (β-PVDF), polyethylene (PE) or fluorinated ethylene propylene (FEP). The authors assumed that VUV irradiation of a PVDF film can induce radical active species at depths up to 50 micrometers, as demonstrated by ESR. Those active species were able to initiate the radical polymerization of a vinylic or acrylate monomer such as acrylic acid through the polymer film, as confirmed by the EDX profile of the film thickness. Similar results were obtained on PE and FEP films, while aromatic polymers such as PET strongly absorbed VUV energy and dissipated it along other pathways. By mixing this process and photolithographic masks, 3D structuration of commercial polymer films was also obtained.

VUV grafting: an efficient method for 3D bulk patterning of polymer sheets by Cecile Baudin, Jean-Philippe Renault, Stephane Esnouf, Serge Palacin and Thomas Berthelot Polym. Chem. 2014, 5, 2990-2996.

Julien Nicolas is a web-writer and advisory board member for Polymer Chemistry. He currently works at Univ. Paris-Sud (FR) as a CNRS researcher.

In this study, Garcia and Miller were inspired to develop improved synthetic routes and novel families of polyoxalates, particularly targeting thermal properties that might allow mimicry of  popular packaging thermoplastics. Polyalkylene oxalates and polyarylene oxalates were successfully synthesized via oxalate metathesis polymerization (OMP), a step-growth polymerization that employs acid-catalyzed ester interchange of dimethyl oxalate and a diol in a 1:1 ratio. The process was optimized in the melt and did not require solvents. Aliphatic/aromatic polyoxalate copolymers derived from 1,10- decanediol and resorcinol bis(hydroxyethyl)ether or hydroquinone bis(hydroxyethyl)ether in varying compositions were also prepared and studied. Incorporation of the aromatic diols into the polymer chain generally afforded increased T_g and T_m. Solid-state degradation studies indicated facile water-degradation of the polyoxalates as molecular weights decreased 81-92% over the course of 13 months in humid air.

Polyoxalates from biorenewable diols via Oxalate Metathesis Polymerization by John J. Garcia and Stephen A. Miller Polym. Chem. 2014, 5, 955-961.

Julien Nicolas is a web-writer and advisory board member for Polymer Chemistry. He currently works at Univ. Paris-Sud (FR) as a CNRS researcher.