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生物可降解共聚物聚丁二酸/对苯二甲酸丁二醇酯(PBST)的序列结构及结晶性研究 总被引:13,自引:0,他引:13
制备了高分子量的聚丁二酸丁二醇酯,并通过与对苯二甲酸二甲酯的无规共聚调节其生物可降解性及力学性能,得到了具有优良机械性能和不同生物降解速度的一系列共聚物,并对共聚物序列结构、热力学性能、结晶性进行了研究.结果表明,该共聚物为无规共聚物,PBS和PBT分别结晶.共聚物的结晶熔点符合无规共聚物的Flory方程. 相似文献
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乙烯基单体-N-取代马来酰亚胺共聚物玻璃化温度研究 总被引:5,自引:2,他引:3
用差示扫描量热仪对乙烯基单体/N-取代马来酰亚胺共聚物的玻璃化温度(Tg)进行测定.研究了共聚物组成、序列结构、乙烯基单体和N-取代马来酰亚胺种类对共聚物Tg的影响.提出了含共聚物组成和序列结构的Tg预测方程,该方程不仅适合于无规共聚物,还适合于具有严重交替倾向的共聚物. 相似文献
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合成了一系列苯乙烯.马来酸酐共聚物(SMA)。并对共聚物的结构进行了表征。用土埋法和CO2释放法研究了共聚物的生物降解性。探讨了分子量、组成、环境等因素对生物降解性的影响,发现共聚物的分子量降低。降解率增大;共聚物中马来酸酐含量提高。降解率增大;适宜的环境有利于生物降解。 相似文献
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结构精确的含氟嵌段共聚物具有优异而独特的化学和物理性能,有广阔的应用前景,因此受到广泛的关注.含氟嵌段共聚物可分为两类,一类是侧基含氟嵌段共聚物,另一类是主链含氟嵌段共聚物.活性聚合为嵌段共聚物的合成提供了最为重要的方法,利用它可以合成结构精确、分子量可控、分子量分布窄的嵌段共聚物.根据单体的反应特性选择不同的聚合方法,可以得到不同的含氟嵌段共聚物.本文主要综述了近几年利用各种活性聚合方法合成结构精确的含氟嵌段共聚物方面的进展. 相似文献
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C60与甲基丙烯酸甲酯共聚物的制备及光电导性能的研究 总被引:2,自引:2,他引:0
通过自由基聚合的方法制备了一系列甲基丙烯酸甲酯和C60的共聚物,实验结果表明,增加引发剂的含量可以大大提高共聚物的产率。用元素分析、GPC和DSC等方法对共聚物进行表征。首次尝试研究了不含导电高分子的C60共聚物体系的光电导性能,结果表明,该类共聚物光电导性能良好。 相似文献
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John F. Quinn Leonie Barner Thomas P. Davis San H. Thang Ezio Rizzardo 《Macromolecular rapid communications》2002,23(12):717-721
The primary mechanism for living polymerisation under a source of gamma radiation at low dose rates is shown to be reversible addition‐fragmentation chain transfer. This was demonstrated by showing that the initial transfer step determines the success of the polymerisation. When an inappropriate leaving group is chosen for the RAFT agent, the polymerisation is non‐living. Under a reversible termination mechanism the ‘living’‐ness should be independent of this initial transfer step. 相似文献
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Reverse iodine transfer polymerization (RITP) is a new controlled radical polymerization technique based on the use of molecular iodine I2 as control agent. This paper aims at presenting the basics of RITP and the strategy that we have followed for the development of this process in the past three years, from the validation in homogeneous solution polymerization up to recent results in heterogeneous aqueous polymerization processes. Typical examples of RITP of butyl acrylate in emulsion and RITP of styrene in miniemulsion are discussed. 相似文献
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Rui Chen Ying Wang Linlin Zhu Zhen Zhang 《Journal of polymer science. Part A, Polymer chemistry》2021,59(23):2972-2979
An ultrafast approach for controlled synthesis of well-defined polysulfonamides is established through organocatalytic anionic ring-opening polymerization (ROP) of N-sulfonyl aziridine in the melt. Several different organobases are investigated, and it is found that N,N,N′,N″,N″-pentamethyldiethylenetriamine (PMDETA) catalyzed ROP of 2-methyl-N-tosylaziridine (TsMAz) gives the desired polymer, while 1,4-diazabicyclo[2.2.2]octane (DABCO) and 1,8-diazabicyclo[5.4.0]-undec-7-ene (DBU) initiate the polymerization along with initiator to produce uncontrolled polymers. Using PMDETA as the catalyst, poly(2-methyl-N-tosylaziridine) with molecular weight over 100 kg/mol can be synthesized in less than 90 s. Various initiators, including carboxylic acid, N-sulfonyl amide, unactivated amine, phenol, and thiol, are applicable for this protocol to give the molecular weight and end-group controlled polymers under the open-flask condition. Combining this ultrafast ROP with ring-opening metathesis polymerization (ROMP), a brush copolymer is facile synthesized. This approach allows the ultrafast metal-free synthesis of polysulfonamide and expands the scope of initiators for the ROP of N-sulfonyl aziridines. 相似文献
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Charles Nason John A. Pojman Charles Hoyle 《Journal of polymer science. Part A, Polymer chemistry》2008,46(24):8091-8096
Thermal frontal polymerization is a process in which a localized reaction propagates through an unstirred system by the coupling of the thermal diffusion and the Arrhenius kinetics of an exothermic polymerization. A trithiol was found to affect the front velocity and the time for inducing a front upon exposure to UV light for trimethylolpropane triacrylate polymerization fronts with either kaolin or calcium carbonate filler present. The addition of trithiol and filler both decreased the front velocity. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 8091–8096, 2008 相似文献
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Shohei Inoue 《Journal of polymer science. Part A, Polymer chemistry》2000,38(16):2861-2871
The story of the outset of the concept of immortal polymerization is presented. Immortal polymerization is the polymerization that gives polymers with a narrow molecular distribution, even in the presence of a chain transfer reaction, because of its reversibility, which leads to the revival of the polymers once dead, that is, the immortal nature of the polymers. As a result, immortal polymerization can afford polymers with a controlled molecular weight, the number of polymer molecules being more than that of the initiator. The compound that plays a leading role is metalloporphyrin, in which the metal‐axial ligand bond has an unusually high reactivity. Immortal polymerization can be carried out in the ring‐opening polymerizations of epoxides, episulfides, and lactones by the selection of an appropriate metalloporphyrin as the initiator and a protic compound as the chain transfer agent. Immortal polymerization is an effective method for synthesizing end‐functional polymers and oligomers with narrow molecular weight distributions. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2861–2871, 2000 相似文献
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Kevin M. Burridge Nethmi De Alwis Watuthanthrige Camryn Payne Richard C. Page Dominik Konkolewicz 《Journal of polymer science. Part A, Polymer chemistry》2021,59(21):2530-2536
An enduring question is: what is the simplest and easiest way to obtain tailored polymers? This communication explores a robust photoiniferter polymerization with only two active ingredients that requires no prior deoxygenation and can be performed on the milliliter scale or sub-milliliter scale. Rather than leaving headspace in the polymerization vessel or scaling reactions up to fill the vessel, this approach fills the headspace of the reaction vessel with mineral oil or inert solvents. This approach can also be applied to polar monomers in aqueous media, using oil as the inert solvent, or to hydrophobic monomers with water as the inert solvent. This method removes enough ambient oxygen that the photoiniferter reaction proceeds with no deoxygenation step, and achieves high conversion and good molecular weight control in 10–20 h in both aqueous and organic solvents. Complex polymer architectures such as multiblock copolymers and gradient polymers were successfully synthesized by this approach. 相似文献