Linear and networked polymers formed by the near simultaneous occurrence of etherification and esterification under mild reaction conditions

Despite the large difference in their nucleophilicity, phenoxide and carboxylate anions take part nearly simultaneously in the aliphatic nucleophilic substitution reaction with 1,4‐dibromo‐2‐butene. This leads to the formation of ether (? O? ) and ester (? COO? ) linkages simultaneously under mild reaction conditions when hydroxyl benzoic acids are employed as nucleophiles. The process yields a new class of polymer broadly classified as unsaturated poly(ether ester) which are potentially functionalizable. This methodology has also been extended for preparing networked polymers by making use of 3,5‐dihydroxybenzoic acid as A₃ type monomer. Copyright © 2011 Society of Chemical Industry     

浅谈改善不饱和聚酯涂料气干性的方法

叙述了不饱和聚酯涂料的成膜机理。列举了目前改善不饱和聚酯底漆干性的主要方法,如薄膜遮盖法、石蜡覆盖法、改变树脂中可共聚的单体、添加醋酸丁酸纤维素、在不饱和聚酯中引入气干性基团等。并对其利弊作了简要的分析。     

主链改性聚醚聚氨酯电解质的合成与表征

用以氧亚甲基连接的聚氧乙烯([OCH_2(OCH_2CH_2)_9]_n,简称OM—PEO)与甲苯二异氰酸酯(简称TDI)反应,得到一种新的线型聚醚聚氨酯(简称OM—PEO—PU),产物分子量大于10~5,因而有望在不破坏OM—PEO优良导电率的前提下提高力学性能。     

Polymorphic behavior of gondoic acid and phase behavior of its binary mixtures with asclepic acid and oleic acid

Molecular properties of polymorphic forms of gondoic acid [cis-C_20:1Δ11ω9 (GOA)] have been studied by X-ray diffraction (XRD), differential scanning calorimetry (DSC), optical microscopy, and Raman scattering, in comparison to those of six principal unsaturated fatty acids: oleic acid [cis-C_18:1Δ9ω9 (OA)], erucic acid [cis-C_22:1Δ13ω9 (ERA)], petroselinic acid [cis-C_18:1Δ6ω12 (PSA)], asclepic acid [cis-C_18:1Δ11ω7 (APA)], palmitoleic acid [cis-C_16:1Δ9ω7 (POA)], and elaidic acid [trans-C_18:1Δ9ω9 (ELA)]. In addition, phase behavior of binary mixtures of GOA and APA and OA was examined by XRD and DSC. The polymorphic structures of GOA are quite similar to those of APA, ERA, POA, and partly to OA. In particular, DSC and Raman scattering studies have shown that gondoic acid exhibits conformational disordering on heating at the ω-chain, a chain segment between the double bond and CH₃ group, as a transition from all-trans (γ form) to gauche-rich (α form) conformations. A miscible mixing phase was observed in the mixture of GOA and APA, yet eutectic phases were observed in the GOA and OA mixtures. This is a remarkable contrast because the binary mixture systems of varying combinations of cis-unsaturated fatty acids examined so far exhibited either eutectic nature or molecular compound formation. It is expected that specific molecular interactions between GOA and APA that originate from the equivalence of the length of the Δ-chain, the chain segment between the cis-double bond and COOH group, and also from the presence of the γ-α order-disorder transformation would be operating to form the miscible mixing phase.     

An Experimental Approach for the Characterisation of Rigid Porous Media and Unsaturated Conductivity Relations

A laboratory procedure for the characterisation of rigid, porous media is developed and tested. The overall objective of the characterisation is to provide a basis for the choice of a relevant unsaturated conductivity relation. With the proposed procedure, the porous materials are characterised through hydraulic conductivity measurements, saturation-pressure measurements, porosity measurements and air entry pressure measurements. The measurements were conducted using water and a selected non-aqueous phase liquid (n-decane), and two types of homogeneous, rigid porous media of different origin (fritted glass samples with guaranteed homogeneity by the manufacturer, and chalk). The laboratory method successfully characterised the fritted glass samples as homogeneous on basis of calculated tortuosity values, measured bubble pressures and measured pore-size density curves. The contact angle between the liquid and the solid had negligible impact when comparing the drainage of water with the drainage of n-decane, and also when comparingn -decane drainage in dry porous media withn -decane drainage in media where a film of water separated then -decane from the pore wall. Also, the differences in saturated conductivities between n-decane and water in both samples of chalk and fritted glass were well predicted on basis of differences in density and viscosity of the liquids. The laboratory procedure was furthermore used for characterisation of the pore space available for non-aqueous liquid flow in partially water-saturated porous media. Then -decane conductivities in the fritted glass samples partially saturated with water were considerably lower than the n-decane conductivities in the dry fritted glass samples.     

POP中的颗粒形貌及其影响因素分析

分析了高不挥发物质量分数聚合物聚醚多元醇(POP)中分散相颗粒形态及粒径分布对其黏度的影响,并讨论了分散剂用量、链转移剂用量、乙烯基单体比例对分散颗粒形态及粒径分布的影响.     

聚酯结构对不饱和聚酯基磁性复合材料性能影响

以4种不同结构的不饱和聚酯为黏接剂制备了磁性复合材料,并对复合材料进行力学性能和热性能测试,研究了聚酯结构对此复合材料的性能影响。结果表明,随着单位质量聚酯中双键含量的降低,复合材料的冲击强度先升高后降低,最大为6.1kJ/m2,弯曲性能呈上升趋势,热性能逐渐降低,材料的黏弹性逐渐明显。     

端羟基聚醚型三乙氧基硅烷偶联剂合成工艺研究

以烯丙基聚醚、三乙氧基硅烷为主要原料,氯铂酸为催化剂,通过硅氢加成反应合成端羟基聚醚基三乙氧基硅烷。研究了原料配比、催化剂用量、烯丙基聚醚相对分子质量及反应温度对反应转化率的影响。结果表明当采用相对分子质量为600的烯丙基聚醚,n(APEG)/n(TES)为1.1、催化剂用量为15mg/L及反应温度为70℃时,反应体系转化率可达100%。最后采用红外光谱对产物端羟基聚烷氧基三乙氧基硅烷(HPTES)结构进行表征。     

聚氨酯改性不饱和聚酯木器底漆的研究

为了提高不饱和聚酯木器底漆的低温打磨性,采用聚氨酯对不饱和聚酯进行改性,形成互穿聚合物网络(IPN)结构,通过IPN协同效应,结合聚氨酯涂料和不饱和聚酯涂料的优点,获得干燥速度快,易打磨,性能优异的漆膜,聚氨酯用量为30%～50%时效果最佳。     

含磷低聚醚的合成及聚氨酯阻燃发泡材料的制备

以甲基亚磷酸二甲脂合成了羟基封端的含磷低聚醚,并用邻苯二甲酸酐吡啶法测定了羟值,磷钼蓝法测定了磷含量,凝胶色谱法对其分子最进行了测定,采用红外对其结构进行了表征。并以此制备了阻燃聚氨酯发泡材料,研究了发泡材料的阻燃性能。结果表明,这种含磷的低聚醚能够有效提高聚氯酯泡沫的阻燃性能,且具有较好的水解稳定性。