长侧链减阻聚烯烃的合成及其抗剪切稳定性的研究

用溶液聚合法,以轻质油为溶剂,一氯二乙基铝/四氯化钛为催化体系,C10-14α-烯烃为单体,合成了一种长侧链聚烯烃类油溶性减阻剂.该聚合物未经脱溶剂处理,减阻率高达45%(添加质量浓度为0.01kg/m3),超过了本体聚合法得到的聚合物(减阻率为40.1%).热重分析表明,聚合物在380℃开始分解,唯一的热失重阶段大约为380℃～450℃.聚合物溶胀前后XRD测试结果显示溶胀前聚合物结构规整性较差,溶胀后使主链和侧链部分展开,规整性提高.最后研究了聚合物溶液的抗剪切稳定性.     

Nucleation effect of inclusion complexes with different polyolefin as guest molecules on the crystallization of polypropylene

The γ‐cyclodextrin (γ‐CD) inclusion complexes (ICs) with four kinds of polyolefin (PO) as guest molecules were prepared. The crystallization behavior of isotactic polypropylene (iPP) blended with the γ‐CD and γ‐CD–PO ICs was investigated by differential scanning calorimetry, polarized optical microscopy, and light scattering. The iPP blended with the ICs was found to exhibit higher crystallization temperature (T_C), smaller spherulites, and faster crystallization rate than those of neat iPP, indicating that the ICs play a role of nucleating agent on the crystallization of iPP and induce accelerated crystallization. The IC with PO having higher T_C as guest molecules showed higher nucleation effect than the IC with PO having lower T_C as guest molecules. The results suggest that the nucleation effect of these ICs was affected by the kinds of the guest molecules. The higher T_C guest molecules could result in higher nucleation effect. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Polymer electrolyte complexes of LiCIO4 and comb polymers of siloxane with oligo-oxyethylene side chains

Polysiloxanes with oligo-oxyethylene side chains of the type —O(CH₂CH₂O)₇CH₃ and —(CH₂)₃O(CH₂CH₂O)_nCH₃ (average n ≈ 7 and 11) were synthesized from poly(hydrogenmethylsiloxane) and characterized by ¹H n.m.r., ²⁹Si n.m.r., i.r. and g.p.c. Cyclic analogues were used as model compounds and synthesized from tetramethylcyclotetrasiloxane. Polymer electrolyte complexes were made from the comb polymers and LiClO₄ by solvent-casting from THF, and their conductivities measured as a function of temperature and studied by differential scanning calorimetry and correlated with their conductivity behaviour. Maximum conductivities close to 10^?4S cm^?1 were achieved at room temperature and at ethylene oxide units to Li⁺ ratios of about 25. Cross-linking or blending with high molecular weight poly(oxyethylene) lowers the conductance somewhat but vastly improves the mechanical properties of the complexes, and the blends with PEO can be cast into thin, flexible and tough films with good conducting properties.     

聚合填充法聚烯烃复合材料的进展

对采用聚合填充法制备聚烯烃系列复合材料的合成技术及材料的结构和性能进行评述。     

环糊精及其包合物的研究与应用

介绍了环糊精及其包合物的合成、结构、包合物形成的热力学与动力学等的研究概况，着重叙述了环糊精的包合作用与环糊精的修饰，描绘了环糊精化学的应用与发展前景。     

The influence of side chains on solubility and photovoltaic performance of dithiophene–thienopyrazine small band gap copolymers

Three small band gap copolymers based on alternating dithiophene and thienopyrazine units were synthesized via Yamamoto coupling and applied in bulk heterojunction solar cells as donor together with PCBM ([6,6]-phenyl C₆₁ butyric acid methyl ester) as acceptor. The polymers have an optical band gap of about 1.3 eV in the solid state and only vary by the chemical nature of the solubilizing side chains. The nature of the side chain has a major effect on solubility and processability of the polymer. Using n-butoxymethyl side chains a soluble, easy to process polymer was obtained that gave the best photovoltaic performance. With short-circuit currents up to 5.2 mA/cm² an efficiency of 0.8% was achieved under estimated standard solar light conditions (AM1.5G, 100 mW/cm²) with spectral response up to 950 nm.     

Interaction of cyclodextrins with side chains of water soluble polymers: A simple model for biological molecular recognition and its utilization for stimuli-responsive systems

This article demonstrates that the interaction of cyclodextrins (CDs) with side chains of water soluble polymers is useful not only as simple models for biological molecular recognition but also as building blocks in nanotechnological applications. In the interaction of CDs with polymer side chains, the selectivity of CDs was enhanced by the steric effect of the polymer main chain and by interaction at multi-sites (i.e., collectivity). Utilizing the interaction of CDs with polymer side chains, stimuli-responsive systems were constructed from simple components.     

Extruded foams prepared from high amylose starch with sodium stearate to form amylose inclusion complexes*

Extruded starch foams were prepared from high amylose corn starch with and without sodium stearate and poly(vinyl alcohol) (PVOH) to determine how the formation of amylose–sodium stearate inclusion complexes and PVOH addition would affect foam properties. X‐ray diffraction and Differential Scanning Calorimetry (DSC) showed that amylose–sodium stearate inclusion complexes were formed by low temperature extrusion and did not dissociate during foam formation by a second extrusion at higher temperatures. In the absence of PVOH, water absorption, and foam shrinkage at 95% RH were decreased because of the hydrophobicity of the complex. PVOH addition increased both the expansion ratio and the shrinkage of the foam, although shrinkage at 95% RH was still less than that observed with uncomplexed amylose. The structural integrity and some tensile properties of stearate‐containing foams were improved by PVOH addition. These results provide the manufacturer of biodegradable starch foams with an inexpensive method for tailoring foam properties for specific end‐use applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43251.     

Graft copolymers with hydrophilic and hydrophobic polyether side chains

Poly(ethylene glycol)methyl ether methacrylate (PEOMA) and oligo(propylene glycol)-4-nonylphenyl ether acrylate (OPOPhNA) were copolymerized by atom transfer radical polymerization (ATRP). Grafting through method was employed in the presence of CuBr/HMTETA or CuBr/PMDETA catalyst/ligand complex in anisole at 70 °C. It yielded a heterografted copolymers containing hydrophilic PEO and hydrophobic OPOPhNA side chains with polymerization degree DP = 68-315 in the presence of PMDETA and DP = 48-195 in the presence HMTETA. Moreover, higher reactivity of PEOMA than OPOPhNA (r_methacrylate > r_acrylate), which was observed during copolymerization, suggested the formation of copolymers with a spontaneous gradient composition starting from the grafted segment of P(PEOMA). The molecular weight distribution (MWD) was increased with DP in the range 1.2-1.6. The X-ray diffraction analysis (WAXS) indicated that larger number of PEO segments generated crystalline properties in the copolymers with amorphous OPOPhNA.     

Thermodynamics of polyolefin blends: small-angle neutron scattering studies with partially deuterated chains

Small-angle neutron scattering is used to evaluate the binary interaction parameter χ in molten blends of polyethylenes having different levels of ethyl branching along the backbone. The labelled chains were partially deuterated to minimize the isotope effect on χ. The present results for equal-volume-fraction binary blends at 150°C can be summarized as χ=0.4×10⁻⁴+0.014ΔX²_br. The first term is from the hydrogen-deuterium isotope effect for chains labelled with about 33% deuterium. The second term is due to chemical composition differences, expressed here as the difference in X_br, the fraction of four-carbon repeat units having an ethyl branch. The observed contributions to χ are in reasonable accord with calculated estimates.     

The gas-phase chemistry of cyclodextrin inclusion complexes

Complexes of cyclodextrins with amino acid analytes are produced in the gas phase and are ideal for the study of molecular recognition. In this Account, we discuss the evidence for the presence of gas-phase inclusion complexes and the nature of the interaction. The use of cyclodextrins as chiral selectors in gas-phase guest-exchange reactions is illustrated, and the nature of the enantioselectivity is discussed. The development of the enantioselective reaction into an analytical method for determining enantiomeric excess is also described.     

Synthesis and characterization of N-phenylmaleimide-methylvinylisocyanate copolymers with polystyrene side chains

Summary N-Substitued maleimide-methylvinylisocyanate copolymers with high glass transition temperature (T_g) was prepared and reacted with 4-hydroxy TEMPO (4-hydroxy-2,2,6,6-tetramethyl piperidinoxy) to yield polymers possessing stable radical at the side chain. The resulting polymers behaved as polymeric counter radicals for the radical polymerization of styrene. Thus, stable free radical mediated polymerization at the side chain was achieved. The resulting graft copolymers were characterized by spectral and thermal analysis. Received: 6 October 1999/Revised version: 7 March 2000/Accepted: 7 March 2000     

Preparation and characterizations of all-biodegradable supramolecular hydrogels through formation of inclusion complexes of amylose

In this study, we found that the hydrogel containing cross-linking points of amylose/PCL graft chain inclusion complexes was obtained by vine-twining polymerization using a water-soluble chitosan-graft-poly(ε-caprolactone) (chitosan-g-PCL). When phosphorylase-catalyzed enzymatic polymerization was performed in the presence of chitosan-g-PCL, the reaction mixture turned into a gel form. The IR spectrum of the sample obtained by lyophilization of the hydrogel indicated that amylose included the PCL graft chains in the intermolecular (chitosan-g-PCL)s to produce cross-linking points. The evaluation of the hydrogels obtained under various conditions was conducted by the shear-viscosity measurement. Because amylose, chitosan, and PCL are known to be enzymatically hydrolyzed, we have investigated enzymatic disruption behaviors of the hydrogels by hydrolysis of these components catalyzed by the corresponding enzymes, i.e., β-amylase, chitosanase, and lipase, respectively. In all cases, the hydrogels were transformed into solution or suspension states, indicating the occurrence of enzymatic disruption of hydrogels. Furthermore, the hydrogel was reproduced when the vine-twining polymerization was carried out in the presence of phosphorylase in the resulting solution by the β-amylase treatment.     

Antibacterial activity of resin-containing triethylenetetramine side chains and/or thiol groups–metal complexes

Four chelating resins containing triethylenetetramine side chains and/or thiol groups were made from macroreticular 2,3-epithiopropyl methacrylate, styrene–divinylbenzene (DVB), or methyl methacrylate–DVB copolymer beads, and then the resins bearing metal ions such as Ag⁺, Cu²⁺, and Zn²⁺ were made. The antibacterial activity of the resins bearing metal ions against Escherichia coli (E. coli) or Staphylococcus aureus (S. aureus) was investigated. The resins containing thiol groups showed the higher adsorption capacity for silver ions than for other metal ions. The resins, which contain both triethylenetetramine side chains and thiol groups, bearing silver ions (RE-TTA-Ag) exhibited high antibacterial activity against bacteria, especially E. coli, without the residual silver ions in water after contacting with bacteria. The activity of the RE-TTA-Ag did not decrease even after reusing several time. © 1996 John Wiley & Sons, Inc.     

侧链结晶PVC的结构和热性能

通过亲核取代反应制备了可侧链结晶的梳型接枝聚氯乙烯(PVC),利用傅里叶变换红外光谱、核磁共振氢谱和凝胶渗透色谱表征了梳型接枝PVC的结构,采用差示扫描量热法研究了接枝率与侧链长度对侧链结晶行为、熔融行为及玻璃化转变温度(tg)的影响。本研究方法可有效地将长链烷基接枝到PVC骨架上,并形成侧链结晶。侧链结晶的熔融焓和熔融温度随接枝率的增大而增大,随侧链的增长而减小。tg随接枝率的增大先降后增,连接含有较长侧链的PVC的tg明显高于不含侧链的PVC。     

Helix formation of charged polypeptides in polyion complexes with weak and strong polyelectrolytes prepared in aqueous alcohols

Using circular dichroism, the helix contents of sodium poly(L -glutamate) (PLGNa) and poly(L -lysine) hydrobromide (PLLHBr) in their weak and strong polyelectrolyte complexes have been estimated in aqueous alcohol solutions. Helix (de)stabilization observed in the systems is compared with earlier results on the PLGNa/PLLHBr polyion complex.     

Corona poling of liquid crystalline polymers with nitroazobenzene side chains

Summary The orientational behavior of liquid crystalline polymers with para-nitro azobenzene as side chains under electric field was studied by UV-visible spectroscopy. The results showed that λ_max of the poled polymer films was around 394nm, compared to that of the unpoled films, the absorption decreased due to poling. The orientational parameters increased linearly with the increase of the electric field. The temporal stability of the poled polymer film is good at room temperature. This kind of materials showed promise application as nonlinear optical component in photorefractive polymers Received: 29 January 1999/Revised version: 19 April 1999/Accepted: 21 April 1999     

Thermotropic aromatic/lactide copolyesters with solubilizing side chains on aromatic rings

Liquid-crystalline polyesters with solubilizing side chains on aromatic rings have been synthesized by melt polycondensation of diacid dichlorides and silylated hydroquinones. Corresponding copolyesters incorporated with lactide units were obtained by addition of oligolactides. The molecular structures of these polymers were verified by spectroscopy techniques. Molecular weights were characterized by gel permeation chromatography. X-ray diffraction studies confirmed that all polyesters are partially crystalline and have self-organized ordered stacking structures. The polyesters can form smectic melts upon heating above the melting temperature. Contact angle measurements and water absorption data of solution cast films showed that the polyesters have relatively high hydrophilicity and decreasing contact angle with increasing amount of lactide moieties.     

含氰基联苯液晶基元侧链的聚酰胺的合成与表征

首先合成了一种含氰基联苯侧基的二胺单体,通过溶液缩聚合成了含氰基联苯液晶基元侧链的聚酰胺。用FTIR和1H NMR对中间体以及二胺单体的结构进行了详细的表征。DSC研究表明,聚酰胺表现出多重相转变行为,结合偏光显微镜的观察,结果表明,此聚酰胺呈现液晶性。进一步的WAXD研究又发现,聚酰胺在20℃附近区域出现多重衍射峰,同时在10℃以下的小角度区出现尖锐的衍射峰,说明形成了一种层状的液晶结构。     

Synthesis and characterization of ion conducting cellulose esters with PEO side chains

Cellulose esters with poly(oxyethylene) (PEO) side chains, denoted COE-1 and HPCOE-1A, were prepared through the homogeneous reactions between cellulose or hydroxypropylcellulose and a PEO monocarboxylic acid in the presence of N,N′-dicyclohexylcarbodiimide and 4-N,N′-dimethylamino-pyridine. The LiCF₃SO₃ complexes of the two polymers were prepared, and the effects of salt concentration on the liquid crystallinity, ionic conductivity and morphology were investigated. It has been found that the two kinds of complexes are both thermotropic liquid crystalline materials and exhibit clearing temperatures, T_c, that increase with increasing salt concentration. The increase in T_c for each system is compensated approximately by a rise in T_g, leaving the liquid crystalline temperature ranges fairly constant. A non-Arrhenius temperature dependence of ionic conductivity is predominant in both systems with the maximum conductivities occurring at [Li]/[O]≈0.07. The environmental scanning electron microscopy reveals a very rough, array-like internal structure for the COE-1 complex at this salt concentration.