液体氟弹性体的合成和表征

通过对液体氟弹性体(低分子量氟弹性体)的分子量及其分布、共聚单体组成和微观结构的分析，发现二溴四氟乙烷对于液体氟弹性体的聚合反应具有明显的分子量调节作用，同时研究了液体氟弹性体聚合物的端基组成和序列结构。     

超临界CO2中含氟聚合物的合成及发展

综述了国内外以超临界CO2为介质的含氟聚合物的聚合反应研究,其中涉及氟烷基丙烯酸酯类单体的均聚和共聚,可熔融加工的四氟乙烯聚合物,离子交换树脂等。研究表明超临界CO2具有一般有机溶剂不具备的优点,在含氟聚合物的合成方面有独特的优势。     

含氟热塑性硫化胶

该项发明主要涉及由氟代烃组成的热塑性硫化胶(TPV)，它能解决诸如合成时TPV易粉化、熔融加工性能差和物理机械性能低下，不能承受后硫化加工等问题。解决这些问题无需借助于经化学改性的标准商品化氟弹性体，或不用具有特别硫化点的单体组分生产氟弹性体。该热塑性硫化胶由氟化的聚合物两相组成，它有优异的机械性能、耐热性和耐油性(包括在舍碱的油中)及易熔融加工性。此外，文中还介绍了它的生产过程。业已发现，可以通过应用氟弹性体组分获得两相组成，即二种和更多种氟弹性体的共混物，其中，至少有一种是亚乙烯基二氟／四氟乙烯／丙烯三元共聚的氟弹性体。     

偏氟乙烯与六氟丙烯自由基溶液共聚

本文介绍了由二叔丁基过氧化物作引发剂,在偏氟乙烯(或称1,1-二氟乙烯(VDF))与六氟丙烯(HFP)溶液中进行的自由基共聚,研究了[VDF]o/[HFP]o初始摩尔比从5.0/95.0至85.2/14.8的一系列8个聚合反应。两个共聚单体均在该范围内进行共聚。再者,只有VDF在该条件下可以均聚。这些无规型共聚物的聚合物成分通过19F核磁共振(NMR)光谱进行计算,该测定方法可以将共聚物中各聚合单元进行定量。以Tidwell和Mortimer法对两个共聚单体的竞聚率(ri)进行估算,显示出共聚物中VDF具有较高的结合能力(rHFP=0.12±0.05,rVDF=2.9±0.6,393K)。经计算得到HFP的Alfrey-Price's Q值和e值分别为0.002(由QVDF=0.008)或0.009(由QVDF=0.015)和+1.44(对eVDF=0.40)或+1.54(对eVDF=0.50),说明HFP是一个电子接受单体。本文也测定了这些含氟共聚物的热性能。除了那些高VDF含量的共聚物之外,其他均为无定形物质。每个产品均只出现一个玻璃化温度(Tg)。同时,从已知的Tg定律,估算了HFP均聚物的玻璃化温度。本文将研究结果与通过文献推断得到的数据进行了比较并进行了讨论。     

电子束辐照交联多接枝共聚物与嵌段双接枝共聚物热塑性弹性体

热塑性弹性体（TPE）由弹性和非弹性的链段共聚而成,是一类重要的聚合物材料。选择合理的分子结构、单体、共聚单元质量分数被认为是优化该类聚合物弹性性能的关键因素。最早的热塑性弹性体是一个弹性体嵌段两端被两个硬嵌段所限制的聚合物。在过去的10年中,新的合成技术应用于合成各种具有精确分子结构设计的接枝共聚物,该项技术的成功开发,使得聚合物主链和侧链的分子量,侧链的分布指数,可接枝点数量,     

烯烃多嵌段共聚物的结构、合成及应用

烯烃多嵌段共聚物是一种新型的聚烯烃热塑性弹性体,主要通过催化乙烯和1-辛烯链穿梭聚合制备得到多嵌段含"软段"和"硬段"的聚合物,其独特结构和性能已经成为新材料的研究热点。本文概述了烯烃嵌段多共聚物的结构和制备合成,并指出了烯烃多嵌段共聚物性能和应用前景。     

一种含氟共聚物乳液的制备及其性能

通过制备一种含有全氟壬烯基的含氟共聚物乳液,并考察其性能,研究了含氟单体对共聚物乳液性能的影响。以K2S2O8为引发剂,丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)和全氟壬烯基烯丙基醚(PFNAE)为共聚单体,采用半连续乳液聚合的方法,制备了带蓝色荧光的含氟乳液。用傅里叶红外(FT-IR)、接触角、差示量热扫描(DSC)和热重(TG)分析等手段对制备的PFNAE-BA-MMA共聚物(PBM)结构和性能进行表征。结果表明:引入含氟单体后,聚合物的疏水性、热稳定性、玻璃化温度(Tg)都有提高。水在含氟共聚物上的接触角随含氟单体用量的增加而增大,当PFNAE占单体总质量的25%时,水的接触角为94.9°;当PFNAE占单体总质量的20%时,共聚物在221℃开始分解,429.5℃分解完全,该共聚物Tg为8.5℃。PFNAE-BA-MMA共聚物具有一定的拒水性和良好的热稳定性。     

VDF、PVDF国内外市场及技术进展

VDF是含氟烯烃的重要品种之一，主要用作合成高分子材料的单体。在氟弹性体方面，VDF是最主要的单体，几乎所有的氟弹性体中都含有VDF组分。     

含氟聚丙烯酸酯防水防油剂的合成及性能研究

以全氟辛酸和全氟辛基磺酰氟为原料，合成了六种含氟丙烯酸酯单体，并进行了溶液聚合和乳液聚合。研究了聚合反应中各种因素对产品性能的影响，测试了产品的防水防油性，与国外同类产品性能进行了比较，提出了含氟单体与非氟单体共聚时降低含氟单体用量，从而降低有机氟防水防油剂成本的途径。     

超临界CO_2中CTFE和BVE的共聚合研究

以超临界CO2为反应介质,制备得到三氟氯乙烯(CTFE)和乙烯基正丁基醚(BVE)共聚物,研究了单体配比、反应温度、引发剂用量、单体浓度对聚合反应及聚合物的结构与性能的影响情况。结果表明:通过控制单体配比及其他实验条件,可以得到不同结构、不同氟含量的含氟聚合物;当单体配比中CTFE的比例增大到一定程度(BVE/CTFE质量比<6/10),实验得到的聚合物是交替共聚物。同时实验发现,聚合反应过程中压力的变化与反应的进程是同步的。     

Thermal stability and surface properties of acrylic PSAs modified by hexafluorobutyl acrylate

The article attempted to prepare special acrylic adhesives with preferable adhesion property and better thermal stability by introducing a fluorinated monomer. The FT-IR result showed that fluorinated monomers and acrylic monomers participated in copolymerization successfully. Furthermore, fluorinated groups performed good compatibility with acrylic resins, based on differential scanning calorimetry curve. According to the TG test under different heating rates, the activation energy of PSAs containing different content of fluorinated monomers was calculated to evaluate the effect of hexafluorobutyl acrylate on heat resistance of PSAs. Then, the findings of contact angle test revealed that the fluorinated PSAs also had rather lower surface energy than ordinary PSAs. Finally, the results of peel strength measurements indicated that the fluorinated PSAs demonstrated excellent adhesion property on various materials, especially low surface energy substrates.     

后过渡催化剂催化烯烃与极性单体共聚的研究进展

综述了近年来后过渡金属催化剂催化烯烃与极性单体共聚的研究进展,后过渡金属催化剂催化乙烯与极性单体共聚的反应条件温和。对聚合机理和极性单体的种类进行了探讨,同时还讨论了共聚条件的变化对聚合产物的影响。     

自缩聚开环超支化聚合反应的动力学分析

通过严格的动力学方法推导出阴离子型自缩聚开环超支化共聚合体系(SCROCP)的分布函数及各级统计矩数,进而给出了该共聚体系的二维重量分布函数、数均、重均分子量及多分散指数的解析公式。在SCROCP中的研究成果可推广到阴离子型自缩聚开环均聚体系(SCROP)中,此时活化剂的当量少于单体的当量,有一些单体没有被活化剂激活成引发剂单体,反应体系实际上是按共聚的机理进行的。计算结果表明,当初始单体含量较高时,移除残余单体可以使体系的多分散指数大大降低。     

Synthesis and Properties of Novel Surface Active Monomers Based on Derivatives of 4‐Hydroxybutyric Acid and 6‐Hydroxyhexanoic Acid

Novel surface active maleate and methacrylate monomers based on derivatives of ω‐hydroxy carboxylic acids have been synthesized. The monomers are comprised of hydrophobic alkyl chains and hydrophilic poly(ethylene glycol), quaternary ammonium, sulfonate and carboxylic fragments. Synthesized monomers sufficiently reduce surface tension at the aqueous solution‐air interface. The copolymerization of synthesized monomers with 5‐tert‐butylperoxy‐5‐methyl‐2‐hexene‐3‐yne monomer and N‐vinylpyrrolidone in solvent and emulsion copolymerization of synthesized peroxide containing surface active monomer with styrene have been carried out. The synthesized surface active monomers have been shown to be suitable emulsifiers for obtaining polystyrene colloid dispersions. It has been ascertained that the surface active copolymers obtained can form stable interpolyelectrolyte complexes with oppositely charged polymers.     

Copolymerization behavior of 2-vinyl-5-methyl furan

Summary The title monomer was copolymerized with methyl methacrylate, isobutyl methacrylate n-butyl acrylate. The results of the copolymerization experiments were analyzed using a nonlinear least squares error-invariables method in order to obtain reactivity ratios for each monomer pair. In all cases the 2-vinyl-5-methyl furan proved to be the more reactive monomer, although this monomer is not as reactive as some other vinyl heterocycles have proved to be in copolymerizations with these same or similar comonomers.     

Role of fluorinated monomer for simple demolding in nanoimprint lithography

In this study, we explored the effect of a fluorinated monomer on nanoimprint lithography (NIL) and determined the optimum amount of fluorinated monomer required in the formulation for better NIL. To estimate the role of the fluorinated monomer for demolding, NIL was conducted using copolymers of nonfluorinated silane monomers and fluorinated silane monomers. Epoxy ring‐opening photopolymerization based on the cationic polymerization mechanism was utilized for the NIL process. The physical properties of the photopolymerized copolymeric materials, such as tensile strength, elongation, modulus, and impact strength, as well as surface characteristics such as the contact angle were reported. Aluminum deposition on the nanoimprinted pattern, which is instrumental in fabricating a wire grid polarizer, was also conducted. According to the study results, the use of a copolymer containing 20 mol % of the fluorinated monomer in NIL proved to be the best formulation for easy demolding and for ensuring optimum levels of the physical properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41317.     

明胶接枝共聚的进展

本文是关于明胶接枝共聚问题近年来进展情况的评述,指出了用乙烯基单体对明胶进行接枝改性的目的和意义。简要介绍了反应介质、原料明胶、单体、引发剂,以及接枝率等有关接枝反应的一般问题。分别讨论了明胶浓度、单体浓度、引发剂浓度、反应温度及时问等变量对接枝反应的影响。介绍了明胶接枝产物的分析鉴定方法。列举了可能的接枝反应机理。此外,还指出了当前在明胶接枝共聚的研究工作中尚未解决和需要进一步研究的问题。     

Phase separation structure and interfacial properties of lattice‐patterned liquid crystal–polymer composites prepared from multicomponent prepolymers

Lattice‐patterned liquid crystal (LC)–polymer composites are representative candidates for the practical application of LC materials in high‐quality flexible displays. In this work, multicomponent prepolymers are used for the fabrication of lattice‐patterned LC–polymer composites via photoinduced phase separation. Phase separation behavior between LC and polymer is closely related to the solubility parameter of acrylate monomers in the prepolymers. The lattice structure of polymer walls formed by photoinduced phase separation between LC and polymers is stoichiometrically controlled by the composition of acrylate monomers with various solubility parameters. However, unlike the polymer wall structure, it is impossible to control the LC–polymer wall interfacial properties just by altering the composition of the acrylate monomers. The interfacial properties are found to be predominantly affected by a specific component, a fluorinated acrylate monomer, in the prepolymers, and thus the anchoring energy of polymer walls is controlled by incorporation of the fluorinated acrylate monomer. By selecting an appropriate combination of acrylate monomers in the prepolymers, both the phase separation structure and driving properties of lattice‐patterned LC–polymer composites can be controlled simultaneously. © 2013 Society of Chemical Industry     

茂金属化合物催化极性烯类单体活性聚合的研究进展

综述了CGC催化剂、单茂催化剂、多核茂金属催化剂、桥联茂金属催化剂,非茂金属催化剂催化极性烯类单体均聚合及极性烯类单体与非极性烯类单体共聚合的研究.茂金属催化剂催化极性烯类单体聚合的机理包括配位聚合机理与活性自由基聚合机理.采用茂金属催化体系可以制备极性烯类单体的均聚物及极性烯类单体与非极性烯类单体的共聚物.不仅拓宽了茂金属催化剂的应用范围,而且可开发出具有新性能的极性聚烯烃树脂.     

Polycarboxylate superplasticizers of acrylic acid–isobutylene polyethylene glycol copolymers: monomer reactivity ratios,copolymerization behavior and performance

Acrylic acid–isobutylene polyethylene glycol (AA-TPEG) copolymers are typical of polycarboxylate superplasticizers (PCEs). AA-TPEG copolymers are prepared via free-radical polymerization with potassium persulfate as the initiator. The obtained copolymers were characterized by gel permeation chromatography (GPC) and infrared spectra (FTIR). The GPC method can break through the former limitations of the instruments and receive instantaneous unreacted and instantaneous monomer concentrations and not the initial monomer feeds. Since TPEG monomer is highly bulky, the common calculation methods for determining monomer reactivity ratios in copolymerization based on terminal copolymerization equation are not suitable. However, this study created non-linear least squares curve fitting of terminal copolymerization equation (NLLSQ-T) and penultimate copolymerization equation (NLLSQ-P) methods, which used Python’s NumPy, SciPy, and SymPy libraries to generate code and did numerical computations, bringing greater accuracy of monomer reactivity ratios. The monomer reactivity ratios were calculated with Fineman–Ross, Kelen–Tüdös, YBR, NLLSQ-T, and NLLSQ-P methods and found to be r _AA = 10.888, r′ _AA = 1.131, r _TPEG = 0.012, and r′ _TPEG = 0.042 for AA-TPEG copolymers. Moreover, this study also explored specific copolymerization behavior of similar structure of copolymers with steric hindrance under penultimate copolymerization equation, such as dependence of the mole fractions in the copolymer on the mole fractions of unreacted monomers in solution, variation of copolymer compositions with conversion and sequence length distribution. The fluidity and flow loss of pastes containing PCEs were investigated, and the appropriate PCEs dosages resulted in a better workability of cement pastes.