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Photoinduced micropattern in an azobenzene polymer film

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Chinese Science Bulletin 2003年第3期48卷 244-246页

作者： ZHANGLingzhi XUZeda 等 instituteofpolymerscience SchoolofChemistryandChemicalEngineeringZhongshanUniversityGuangzhou510275.China instituteofpolymerscience SchoolofChemistryandChemicalEngineeringZhongshanUniversityGuangz

The micropattern observed in the amorphous azobenzene polymer film by degenerated four-wave mixing has been reported. Patterns with well-defined structures are examined with the scanning electron microscopy and the polarizing optical microscopy. It is demonstrated that the control of photoinduced micropattern in the azobenzene polymer film is possible by using appropriate polarized writing beams with total incident power exceeding a certain threshold.

关键词：偶氮苯聚合物薄膜光异构作用感光定向作用光诱导偏振激光微晶结构

Synthesis and Thermal Properties of a Novel Nitrogen-containing Epoxy Resin

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Chinese Chemical Letters 2005年第4期16卷 547-550页

作者： XingHongZHANC HongMeiWAN YuQinMIN ZuoFANC GuoRongQI instituteofpolymerscience ZhejiangUniversityHangzhou310027

A new nitrogen-containing epoxy resin (XT resin) was synthesized from chain extension of xylenephenolformaldehyde resin (XPF) and triglycidyl isocyanurate (TGIC) in the presence of base catalyst. FT-IR and H-NMR analysis confirmed the chemical structure of XT resin. It was 1 cured with dicyandiamide (DICY) and diaminodiphenyl sulfone (DDS). Dynamic mechanical analysis (DMA) results showed that the introduction of triazine ring provides epoxy polymer with good thermal stability. Furthermore, high char yields at 800℃ in thermogravimetric (TGA) analysis indicated that XT resin had potential flame retardance.

关键词： Nitrogen-containing epoxy resin xylenephenolformaldehyde resin (XPF) triglycidyl isocyanurate (TGIC) thermal stability.

Dihydroxy Capped Triblock DTC and CL Oligomers Prepared by an Alkyl Glycol/Yttrium Phenolate System

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Chinese Chemical Letters 2005年第2期16卷 282-284页

作者： WeiCHEN JunLING ZhiQuanSHEN instituteofpolymerscience ZhejiangUniversityHangzhou310027

Dihydroxy capped triblock oligomers of 2, 2-dimethyltrimethylene carbonate (DTC) andε-caprolactone (CL) with number-average molecular weight from 3,000 to 12,000 g/mol have beensynthesized by alkyl glycol initiator in the presence of yttrium tri(2, 6-di-tert-butyl-4-methylphenolate)s (Y(OAr)3) catalyst. They are expected to be used as macroinitiators for thedesign of new polymeric materials.

关键词： Rare earth catalyst block oligomer 2 2-dimethyltrimethylene carbonate ε-caprolactone.

Syntheses and Surface Properties of Polyacrylonitrile-based Copolymer Membranes Containing Sugar Moieties

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Chemical Research in Chinese Universities 2005年第3期21卷 355-359页

作者： HUANGXiao-jun WANLing-shu DAIZheng-wei KOURui-qiang XUZhi-kang instituteofpolymerscience ZhejiangUniversityHangzhou310027P.R.China

To improve the hydrophilicity of polyacrylonitrile-based membranes, sugar moieties were incorporated into acrylonitrile-based copolymers via the radical copolymerization of α-allyl glucoside(AG) with acrylonitrile(AN) with 2,2′-azobis-iso-butyronitrile(AIBN) as the initiator in dimethyl sulphoxide(DMSO). It was found that the yield increased with the increase of the initiator concentration and reaction time, while it decreased with the increase of the monomer molar ratio of AG to AN. Raising the AG proportion in the monomer mixture resulted in the increase of the AG content in the copolymer. M_v of the copolymers decreased with increasing the AG monomer fraction in feed. The copolymers were fabricated into dense membranes and their surface properties were studied by means of the water contact angle measurement and platelet adhesion tests. It was found that the static water contact angle on the membrane decreased significantly from 70° to 33° with the increase of the AG content. The adhesive number of platelets on the membrane surface also decreased significantly with increasing AG content in the copolymers. These results demonstrate that the hydrophilicity and biocompatibility of the acrylonitrile-based copolymer membranes could be improved efficiently by the copolymerization of acrylonitrile with vinyl carbohydrates.

关键词： Polyacrylonitrile Sugar-containing copolymer Surface property Hydrophilicity Platelet adhesion

Ring-opening Polymerization of D,L-Lactide by Lanthanide Tris（2,4,6-trimethylphenolate）： Characteristics and Kinetics

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Chinese Journal of Chemistry 2005年第5期23卷 613-616页

作者：樊玲熊玉兵涂克华沈之荃 instituteofpolymerscience ZhejiangUniversityHangzhouZhejiang310027China

Tris(2,4,6‐trimethylphenolate) lanthanide [Ln(OTMP) 3 ] has been prepared and employed for ring‐opening polymerization of D,L ‐lactide (LA) as single‐component catalysts. The characteristics, kinetics and mechanism were examined. The polymerization is first‐order with respect to monomer and initiator concentration, and the overall activation energy amounts to 62.9 kJ/mol. DSC curve disclosed the random structure of PLA. 1 H NMR spectrum analysis demonstrates that the polymerization of LA proceeded through acyl‐oxygen bond cleavage.

关键词： lanthanide tris(2,4,6‐trimethylphenolate) ring‐opening polymerization D,L‐lactide

Thermal Behavior of Poly(trimethylene-co-ethylene terephthalate)

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Chinese Chemical Letters 2005年第7期16卷 971-974页

作者： YongXU ShengRongYE JinWenQIAN instituteofpolymerscience ZhejiangUniversityHangzhou310027

Poly (trimethylene-co-ethylene terephthalate) with various compositions of diol has been synthesized. The crystallization of copolyesters with high comonomer content was observed by both wide-angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC). It was found that the copolyesters become less crystallizable with the involvement of the comonomer, the crystals of crystallizable copolyesters come from PTT or PET homopolymers. The glass transition temperature (Tg) of the copolyester increases with increasing PET component in the copolyester, and the relationship between Tg and composition obey both Fox equation and additive law, the former is better in describing this relationship.

关键词： Copolyester polytrimethylene terephthalate polyethylene terephthalate thermal beha- vior.

Ultrafast Energy Transfer and Enhanced Two-Photon Absorption in a Novel Porphyrin Side-Chain Polymer

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Chinese Physics Letters 2004年第12期21卷 2521-2524页

作者：王惠黄亚萍邓莉赵福利林位株王坚梁兆熙 StateKeyLaboratoryofPhotoelectronicMaterialsandTechnologies ZhongshanUniversityGuangzhou510275 instituteofpolymerscience ZhongshanUniversityGuangzhou510275

Ultrafast relaxation processes and transient two-photon absorption are studied in a novel porphyrin side-chain polymer, 5-hydroxy-10,15,20-triphenyl-porphyrin-poly(glycidyl methacrylate) (HTPP-PGMA), by using picosecond luminescence spectroscopy and femtosecond pump–probe techniques. HTPP-PGMA exhibits the ultrafast initial luminescence decay (~300ps), which is absent in the conventional porphyrin monomer such as TPP. Enhanced two-photon absorption was observed in HTPP-PGMA; the corresponding Im χ(3) is about 2.8×10−11esu, which is almost one order of magnitude larger than that of the conventional porphyrin monomer (TPP) (~1.3×10−12esu). The ultrafast energy transfer plays an important role in the excited-state relaxation dynamics observed in HTPP-PGMA. The potential application of HTPP-PGMA in optical switching is discussed.

关键词： Excited states

A Novel Approach for the Surface Modification of Polymeric Membrane with Phospholipid Polymer

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Chinese Chemical Letters 2004年第8期15卷 993-996页

作者： QingWenDAI ZhiKangXU JianWU instituteofpolymerscience ZhejiangUniversityHangzhou310027 DepartmentofChemistry ZhejiangUniversity，Hangzhou310027

A new economic and convenient method to modify the surface of microporous polypropylene (PP) membranes with phospholipid polymer was given. The process included the photo-irradiated graft polymerization of N,N-dimethylaminoethyl methacrylate (DMAEMA) and the ring-opening reaction of the grafted polyDMAEMA with 2-alkyloxy-2-oxide-1,3,2-dioxo-phospholanes (AOP). Four AOPs, whose alkyloxy groups consisted of dodecyl, tetradecyl, hexadecyl and octadecyl moieties, were used to convert the grafted polyDMAEMA to phospholipid polymers. FT-IR spectra confirmed the chemical change of membrane surface. Platelets adhesion experiment indicated that PP membrane with excellent blood compatible surface could be fabricated by this method.

关键词： Surface modification phospholipid polymer platelets adhesion.

A Kinetic Evidence for the Nitroxyl Radicals Recycling Mechanism in the Photostabilizing Process of HALS

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Chinese Chemical Letters 2003年第10期14卷 1085-1088页

作者： XiaoXuanLIU XingHongZHANG GuangGuoWU JianWenYANG ZhaoHuaZENG YongLieCHEN DepartmentofChemistry ShantouUniversityShantou515063 instituteofpolymerscience ZhongshanUniversityGuangzhou510275

The photoinduced bulk polymerization of a reactive-hindered amine light stabilizers (r-HALS), 4-acryloyl-2, 2, 6,6-tetramethylpiperidinyl (ATMP), was performed at 80 C by using a DPC technique. An unique periodic exponential attenuation-type oscillating curve was found when the polymerization was carried out in air, but this phenomenon was not found in nitrogen. It is supposed that this unique kinetic performance may be attributed to nitroxyl radicals that are produced in situ from the oxidation of ATMP. ATMP polymer with narrow polydispersity (d = 1.03) can be obtained by photoinduced solution polymerization of ATMP. The signal detected in ESR may be assigned to the nitroxyl radicals in the matrix of ATMP polymer. Since this kind of recycling of nitroxyl radicals is well documented for the photostabilizing mechanism of HALS, the present results may serve as a kinetic evidence for this mechanism.

关键词： Photopolymerization kinetics reactive-HALS (r-HALS) periodic exponential attenuation-type oscillating cycle photostabilizing mechanism nitroxyl radicals (>N-O).