结构可控含氟共聚物的合成及其应用研究新进展

近年来,含氟聚合物以其优异的耐热性、耐氧化性、耐候性、耐腐蚀性以及低介电常数、低表面能等特点,在疏水材料、抗污材料、表面活性剂、造影剂等领域具有广泛的应用前景,受到研究者的密切关注,各种拓扑结构的含氟共聚物被设计合成出来并在相关领域得到应用。本文首先简要介绍了含氟聚合物的性质和研究现状,然后详细叙述了可逆加成-断裂链转移聚合（RAFT）、原子转移自由基聚合（ATRP）、碘转移自由基聚合（ITP）、单电子转移活性聚合（SET-LRP）、氮氧稳定自由基聚合（NMP）以及活性阴离子聚合（LAP）等聚合方法在结构可控含氟共聚物合成中的研究新进展,并对其聚合机理、优缺点以及所得共聚物的性质和应用进行了总结,最后对结构可控含氟共聚物的设计、合成及实际应用前景进行了展望,提出发展绿色环保功能性含氟聚合物将是未来的主要研究热点。     

AB,BAB and (AB)3 poly(ε‐caprolactone)‐based block copolymers with functionalized poly(meth)acrylate segments

Linear and star‐shaped poly(ε‐caprolactone) (PCL) block copolymers containing poly(meth)acrylate segments with glycidyl, 2‐(trimethylsilyloxy)ethyl and tert‐butyl pendant groups were synthesized using mono‐, di‐ and trifunctional PCL macroinitiators and appropriate (meth)acrylate monomers by controlled radical polymerization. The well‐defined structures with narrow molecular weight distributions indicate the coexistence of semi‐crystalline PCL and amorphous poly(meth)acrylic phases. The hydrophobic nature of the block copolymers can be easily converted to amphiphilic, which with biodegradable and biocompatible PCL segments are promising as polymeric carriers in drug delivery systems. © 2012 Society of Chemical Industry     

丙烯酸酯光致抗蚀干膜制备

研究了 (甲基 )丙烯酸酯各组份对成膜树脂及抗蚀干膜性能的影响 ,并就曝光时间、光敏引发剂品种、活性单体对干膜性能的影响也进行了讨论。     

Novel reworkable resins: thermo‐ and photo‐curable di(meth)acrylates

The aim of the study reported in this paper was to develop new di(meth)acrylates having aromatic units and thermally degradable units in their molecules. It was also the aim to clarify the photo‐curing and degradation properties of the new monomers. Di(meth)acrylates having aromatic units and thermally degradable units were synthesized. As thermally cleavable linkages, tertiary ester moieties were incorporated into the di(meth)acrylates. Three types of processes for curing and degradation of the cured resins were studied: thermal curing and thermal degradation; thermal curing and photodegradation; and photo‐curing and thermal degradation. In the thermal curing and photodegradation process, di(meth)acrylate films containing a thermally induced radical initiator and a photoacid generator (PAG) became insoluble in solvents on heating. The cured films became soluble in solvents after ultraviolet irradiation followed by baking. The re‐dissolution behaviors were strongly affected by the structures of the PAGs. A mechanism for the photo‐ or thermo‐curing and photoassisted thermal degradation was studied using Fourier transform infrared, ¹H NMR, thermogravimetric, mass spectrometric and size exclusion chromatographic analyses. Copyright © 2009 Society of Chemical Industry     

(甲基)丙烯酸烷基酯的负离子聚合Ⅰ.聚合特点及适用的单官能团引发剂体系

综合分析了近年来有关(甲基)丙烯酸烷基酯负离子聚合所取得的成就,包括该类单体对负离子聚合的重要意义、聚合难点和解决办法.介绍了聚合特点和单官能团引发剂体系.     

Methyl acrylate polymers as suitable materials for the conservation of stone: performance improvements through atom transfer radical polymerization

Acrylic polymers are a suitable category of materials for application in building stone conservation mainly due to their peculiarities (i.e., easy to apply, low cost, good adhesive and cohesive properties, and high solubility in many organic solvents). The performances of polyacrylates have been improved through atom transfer radical polymerization (ATRP). Polymers were obtained with low polydispersity, controlled molecular weight, and showing better stability to UV irradiation than products obtained by radical polymerization. New poly(methyl acrylate-co-perfluoropolyethers) were also prepared via ATRP, using a perfluoropolyether derivative as initiator, showing the possibility of synthesizing copolymers between acrylates and perfluoropolyethers in common solvents. Protective efficiency of poly(methyl acrylate-co-perfluoropolyether) was close to that of commercially available products.     

Molecular design of damping rubber based on polyacrylate‐containing silicone

A series of damping rubbers based on poly(meth)acrylate and poly(meth)acrylate‐containing silicone rubbers has been prepared. The dynamical mechanical properties were evaluated by using a dynamic mechanical viscoelastometer (DMA). A detailed investigation is reported on the relationship of the damping capability of the poly(meth)acrylate rubbers with their composition and macromolecular architecture. Also discussed is the effect of two kinds of silicone elastomers on the damping performance of the polyacrylate‐containing silicone rubber. The results indicate that, in vulcanized rubber systems, both statistical copolymerization for multiple monomers and blending between immiscible polymers with close T_gs facilitate broadening the glass transition peaks. Furthermore, the molecular design is quite an effective approach in which the multiple monomers whose polymers have a ladder‐changing T_g are used to synthesize the damping rubber with the broad effective functional area. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 746–751, 2002     

含硅(甲基)丙烯酸酯在涂料工业中的研究和应用进展

综述了含硅(甲基)丙烯酸酯单体的种类、制备方法、聚合物的表面性能及其在表面处理、涂料和紫外光固化、电子束固化领域中的研究和应用进展。     

Biocompatible and bioadhesive hydrogels based on 2-hydroxyethyl methacrylate, monofunctional poly(alkylene glycol)s and itaconic acid

Summary Novel poly(Bisomer/HEMA/IA) hydrogels were prepared by radical copolymerization of poly(alkylene glycol) (meth)acrylates, i.e. short chains Bisomers, 2-hydroxyethyl methacrylate (HEMA) and itaconic acid (IA) in a mixture of water/ethanol as solvent. These hydrogels were characterized in terms of swelling in conditions similar to the biological fluids (pH range 2.20–7.40 buffer solutions), compression-strain measurements, thermal properties and morphology. The influence of the type of Bisomer and of the itaconic acid on swelling and mechanical properties, as well as on morphology and thermal behavior of the resulting hydrogels, were investigated. The in vitro study of biocompatibility, carried out with the hydrogels containing different types of Bisomers, showed no evidence of cell toxicity nor any considerable hemolytic activity. All hydrogels showed satisfactory bioadhesive properties, so these materials have potential as drug carriers or biological glue and sealants.     

Synthesis of amphiphilic PVC‐b‐poly(hydroxypropyl acrylate) (PHPA)‐b‐PVC block copolymers with low PHPA contents and different molecular weights by (Single Electron Transfer)—(Degenerative Chain Transfer) living radical polymerization

The aim of this work was to synthesize new amphiphilic block copolymers, based on poly(vinyl chloride) (PVC) and containing poly(hydroxypropyl acrylate) (PHPA), by using the controlled/“living” radical polymerization (CLRP) method. Various block copolymers containing a small proportion of PHPA were prepared, each having a different molecular weight. The technique used was the same as that employed in the production of commercial PVC made by free‐radical polymerization. The materials were characterized in terms of their molecular structure, morphology, particle size, and surface and thermal properties. The CLRP preparation of block copolymers that are based on PVC and have low contents of other monomer units opens the possibility of synthesizing new materials whose properties are close to those of PVC but have new properties that may considerably enhance their performance. The incorporation of small amounts of PHPA into PVC block copolymers provided greater surface hydrophilicity and improved thermal stability while maintaining relevant processing properties, such as particle size and average molecular weight, so that they close to those of conventional PVC homopolymers. J. VINYL ADDIT. TECHNOL., 19:157‐167, 2013. © 2013 Society of Plastics Engineers     

Thermoresponsive poly(oligo ethylene glycol acrylates)

Thermoresponsive polymers have been the subject of numerous publications and research topics in the last few decades mostly driven by their easily controllable temperature stimulus and high potential for in vitro and in vivo applications. P(NIPAAm) is the most studied amongst these polymers, but recently other types of polymers are increasingly being investigated for their thermoresponsive behavior. In particular, polymers bearing a short oligo ethylene glycol (OEG) side chain have been shown to combine the biocompatibility of polyethylene glycol (PEG) with a versatile and controllable LCST behavior. These polymers can be synthesized via controlled radical polymerization techniques from various monomers consisting of an OEG chain and a polymerizable group like a (meth)acrylate, styrene or acrylamide. OEG acrylates offer significant advantages over, e.g., OEG methacrylates as the lower hydrophilicity of the backbone facilitates thermoresponsive behavior with smaller, more defined side chains. Furthermore, PEG acrylates can be polymerized using all major controlled radical polymerization techniques, unlike OEG methacrylates. This review will focus on OEG acrylate based (co)polymers and will provide a comprehensive overview of their reported thermoresponsive properties. The combination and comparison of this data will not only highlight the potential of these monomers, but will also serve as a starting point for future studies.     

Block, blocky gradient and random copolymers of 2-ethylhexyl acrylate and acrylic acid by atom transfer radical polymerization

The controlled synthesis of low-T_g poly(2-ethylhexyl acrylate) (P2EHA) and derived random, block and blocky gradient copolymers via atom transfer radical polymerization (ATRP) is described. After optimizing the reaction conditions for the homopolymerization of 2EHA via ATRP, the synthesis of a variety of copolymers with poly(t-butyl acrylate) (PtBuA) was investigated. First, AB-block copolymers were targeted, starting from P2EHA and PtBuA as macroinitiators. Second, random copolymers of tBuA and 2EHA with different monomer ratios were synthesized. Finally, the synthesis of “blocky” gradient copolymers via a one-pot procedure was investigated, starting with the homopolymerization of tBuA, followed by the addition of 2EHA. The hydrolysis of the PtBuA-segments to poly(acrylic acid) (PAA), which was carried out with methanesulfonic acid, resulted in block, blocky gradient and random copolymers consisting of PAA and P2EHA. Solubility testing of the copolymers in slightly basic water (pH ∼ 9) demonstrated that the gradient structure significantly enhances solubility compared to the block copolymer structures with equal composition. The polymers have been characterized by MALDI-TOF MS, GPC and ¹H NMR.     

The effect of monomer structure on oxygen inhibition of (meth)acrylates photopolymerization

Oxygen inhibition during the free-radical photopolymerization of various monomers containing ether groups was investigated using photo-DSC and real-time FTIR (RTIR). Methacrylates and acrylates containing different number and types of ether groups were selected to determine the effects of ether group concentration and structure on oxygen inhibition. Also, the oxygen sensitivity of the free-radical polymerization of methacrylate and acrylate was compared. Compared to acrylates, methacrylates are much less sensitive to oxygen. Model poly(tetramethylene oxide) and poly(propylene glycol) system were evaluated to determine the effect of ether groups on polymerization kinetics in air. The polymerizations of the (meth)acrylates containing ether groups were found to be relatively insensitive to oxygen inhibition. The reduction of oxygen inhibition occurs by a series of chain transfer/oxygen scavenging reactions.     

Surface Energy and Thermal Stability Studies of Poly(dimethyl siloxane)–Poly(alkyl(meth)acrylate) Copolymers

The correlation between the surface energy and thermal stability of polymers plays an important role in engineering of plastic materials. In this work, microstructural characteristics of copolymers of poly(dimethyl siloxane) with benzyl methacrylate, ethyl methacrylate, and methyl acrylate are correlated with their surface energy and thermal stability. The poly(dimethyl siloxane) segments in the copolymer chains affected the hydrophobic behavior. The surface energy of the synthesized copolymers decreased by increasing segments of alkyl methacrylates. The thermal stability of copolymers suggesting that heat resistance of poly(dimethyl siloxane) copolymers used in this correlation can be improved by adjusting the units of alkyl methacrylates in copolymers.     

High molecular weight diblock and ABA/ABC triblock copolymers of tert‐butyl (meth)acrylate

AB diblock copolymers were prepared by use of poly(tert‐butyl (meth)acrylate) (PtBA/PtBMA) as monofunctional macroinitiator in atom transfer radical polymerization of various (meth)acrylates (methyl, butyl) in the presence of the CuBr/N, N, N′, N′, N″‐pentamethyldiethylenetriamine catalyst system. Then using the diblock copolymer as macroinitiator with a bromine atom at the chain end, ABC and ABA triblock copolymers containing at least one PtBA or PtBMA segment were synthesized via polymerization of the selected (meth)acrylic monomer. Gel permeation chromatography was applied to determine molecular weights and polydispersity indices. The latter, for block copolymers prepared without deactivator addition, were in the range 1.2‐1.6 with a high degree of polymerization (150‐500). The chemical compositions of the block copolymers were characterized with ¹H nuclear magnetic resonance. The kind of combined segments and their lengths influenced the glass transition temperature (T_g) determined by differential scanning calorimetry. Copyright © 2012 Society of Chemical Industry     

Poly(ethylene glycol)-block-poly(butyl acrylate). I. Synthesis

Prepolymers of poly(ethylene oxide) (Pre-PEO) were synthesized by reacting azoisobutyronitrile (AIBN) with poly(ethylene glycol) (PEG), and their structures were characterized by IR and UV. The molecular weight of pre-PEO was related to the feed ratio and reaction time. These prepolymers can be used to prepare block copolymers—poly(ethylene oxide)-block-poly(butyl acrylate) (PEO-b-PBA) by radical polymerization in the presence of butyl acrylate (BA). Solution polymerization was a suitable technique for this step. The yield and the molecular weight of the product were related to the ratio of the prepolymer to BA, the reaction time, and temperature. GPC showed that the molecular weight increased with a higher ratio of BA to pre-PEO. The intrinsic viscosity of the copolymers was only slightly dependent on reaction time, but decreased at higher reaction temperatures, as did the amount of PBA homopolymer. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:1667–1674, 1997     

Study of optically active methacrylates containing 1,1′‐binaphthyl side‐groups polymerized by anionic,group transfer and free radical methods

Optically active and racemic poly(meth)acrylates with pendant 1,1′‐binaphthalene moiety of 2‐methacryloyloxy‐ and 2‐acryloyloxy‐2′‐methoxy‐1,1′‐binaphthalene (MAMBN and AMBN) were synthesized by anionic, group transfer and free radical polymerization methods. Their polymerizability and chiroptical properties are somewhat different, depending on the three types of polymerization methods used. The yields for poly(MAMBN)s are lower than for poly(AMBN)s. The optical rotation of the optically active polymers is identical to that of the corresponding monomers. The values of specific rotation of optically active poly(AMBN)s are much larger than those of optically active poly(MAMBN)s. © 2002 Society of Chemical Industry     

Disparate polymerization facilitates the synthesis of versatile block copolymers from poly(trimethylene carbonate)

A disparate polymerization technique is utilized for preparing versatile block copolymers from poly(trimethylene carbonate) (poly(TMC)). In this study, 4-(chloromethyl)benzyl alcohol (CBA) is used for the disparate polymerization. The hydroxyl group of CBA is involved in ring-opening polymerization and the benzyl chloride group is involved in incorporating dithiocarbamate for pseudo-living radical polymerization. First, TMC is polymerized from the hydroxyl group of CBA by using an organocatalyst. The benzyl chloride group in CBA is modified using a dithiocarbamate, and then vinyl and methacrylate monomers are polymerized by photo-driven pseudo-living radical polymerization. The resulting block copolymers are versatile and the molecular weight distribution is reasonably narrow. In the present study, N-isopropylacrylamide, acrylamide glycolic acid, and 2-hydroxyethyl methacrylate are used for the disparate polymerization. The resulting block copolymers could be well dissolved in water by incorporation of hydrophilic segment into hydrophobic poly(TMC). The solution property is characterized in terms of hydrophobic domain formation and phase transition under ambient conditions. Moreover, enzymatic degradation is evaluated by using a copolymer-coated substrate. The block copolymer synthesis technique is considerably versatile, and the resulting polymer function can be freely designed. The disparate polymerization technique is a promising approach that provides universal materials for integrating biodegradable polyesters and functional polymers.     

One-step synthesis of poly(2-oxazoline)-based amphiphilic block copolymers using a dual initiator for RAFT polymerization and CROP

A range of poly(2-oxazoline) (POx)-based amphiphilic block copolymers were synthesized using 4-cyano-4-(dodecylthiocarbonothioylthio)pentyl-4-methylbenzenesulfonate (CDPS) as a dual initiator for reversible addition-fragmentation chain transfer (RAFT) polymerization and cationic ring-opening polymerization (CROP) in a one-step procedure. Methyl (meth)acrylate, butyl (meth)acrylate, tert-butyl (meth)acrylate, and N-isopropylacrylamide were polymerized for the hydrophobic block, and 2-methyl-2-oxazoline and 2-ethyl-2-oxazoline were used as the hydrophilic block. RAFT polymerization and CROP proceeded independently in a controlled manner and resulted in amphiphilic block copolymers with a narrow molecular weight distribution. CDPS was found to be a useful dual initiator for the one-step synthesis of POx-based amphiphilic block copolymers via a combination of RAFT polymerization and CROP.