A chiral azobenzene-containing N-propargylamide monomer, that is, (R)-2-(4-phenylazophenoxy)-n-prop-2-ynyl-propionamide, was prepared and polymerized in the presence of a rhodium catalyst to yield an optically active polyacetylene. The 1 H NMR analysis of the polymer indicated a predominant cis structure of the backbone (cis concentration ¼ 80%); and the chiroptical property studies showed an enhanced optical rotatory power and a strong Cotton effect, indicating the formation of a secondary helical conformation. A reversible optical modulation of chiroptical properties of the polymer due to the reversible photoisomerization of the azobenzene was observed. V V C 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6047-6054, 2006

Abstract1‐Alkynes containing azobenzene mesogenic moieties [HCC(CH2)9O phNNphOR; R = ethyl (1), octyl (2), decyl (3), (S)‐2‐methylbutyl (4), or (S)‐1‐ethoxy‐1‐oxopropan‐2‐yl (5); ph = 1,4‐phenyl] were synthesized and polymerized in the presence of a Rh catalyst {(nbd)Rh+[B(C6H5)4]−; nbd = 2,5‐norbornadiene} to yield a series of liquid‐crystalline polymers in high yields (e.g., >75%). These polymers had moderate molecular weights (number‐average molecular weight ≥ 12,000), high cis contents in the main chain (up to 83%), good thermal stability, and good solubility in common organic solvents, such as tetrahydrofuran, chloroform, and dichloromethane. These polymers were thoroughly characterized by a combination of infrared, nuclear magnetic resonance, thermogravimetric analysis, differential scanning calorimetry, polarized optical microscopy, and two‐dimensional wide‐angle X‐ray diffraction techniques. The liquid‐crystalline behavior of these polymers was dependent on the tail group attached to the azobenzene structure. Poly‐1, which had the shortest tail group, that is, an ethyl group, showed a smectic A mesophase, whereas poly‐2, poly‐3, and poly‐5, which had longer or chiral tail groups, formed smectic C mesophases, and poly‐4, which had another chiral group attached to the azobenzene structure, showed a chiral smectic C mesophase in both the heating and cooling processes. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4532–4545, 2006

Low‐loss slab waveguides with air as overcladding based on a high glass transition temperature (Tg) polycarbonate were fabricated through spin‐coating. Optical absorption and thermo‐optic coefficient were investigated by spectrum analysis and prism coupler, respectively. Prism‐coupling and charge‐coupled device (CCD) camera imaging method were exploited together to evaluate the overall propagation loss of slab waveguides. The measured results of prism coupler were 0.282 dB/cm at 1310 nm and 0.197 dB/cm at 632.8 nm, whereas 0.07 dB/cm at 632.8 nm using CCD camera imaging method. Based on the same material, straight ridge waveguides and multimode interference couplers were fabricated through photolithograph and reactive ion etching, revealing smooth sides and excellent definition. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers.

A new type of branched copolymer, poly(l-lactide)2-b-poly(l-glutamic acid), based on polypeptide PLGA is synthesized by the ring-opening polymerization of N-carboxyanhydride of γ-benzyl-l-glutamate with amino-terminated PLLA2–NH2 and subsequent deprotection.

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In order to accurately determine the degradation performance of polyolefin-based degradable plastics, the concept of bioassimilated carbon is proposed for the first time in this paper; the bioactive and hydrophilic organic carbon in plastic degradation products is defined as bioassimilation carbon. A method for the detection of the carbonyl index and bioassimilated carbon conversion rate in polyolefin degradable plastics was developed to quickly identify its degradation performance. The measurement results show that the bioassimilated carbon conversion rate of more than 70% can be used to replace the biodegradation rate index to achieve the purpose of quickly identifying the degradation performance of plastics. The deterioration detection cycle proposed by the current common standards implemented in American Society of Testing Materials: ASTM D6400 “Specification for Composting Plastics” can be shortened from 1 year to 1 month. The standard system for catalytic degradation of plastics provides detection methods for polyolefin-based catalytic degradation materials (microplastics), and solves the problems of long detection cycle and poor detection efficiency. Thus, this method has promise for use as a relevant standard method for accurately providing a reference for the assessment.

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