UV固化丙烯酸酯化有机硅及杂化材料的研究与应用

丙烯酸酯化有机硅及杂化材料因兼具有机硅材料的优异性能和光固化的高效、节能及环保等特点而得到广泛的应用。文章综述了光敏性丙烯酸酯化有机硅单体的种类、结构特点及其制备方法,分析了紫外光（UV）固化后聚合物及其杂化材料的性能,介绍了它们的研究与应用现状及其发展前景。     

Barrier Properties OF Inorganic-Organic Polymers: Influence of Starting Compounds,Curing Conditions and Storage-Scaling-Up to Industrial Application—

With a new kind of barrier coating material, namely inorganic-organic polymers, it is possible to obtain high-barrier properties for oxygen, water vapor, and flavor permeation. These hybrid polymers can be synthesized by the sol-gel technique. Network forming reactions and degrees of condensation in the coating sols as well as in the cured coating materials were characterized using ²⁹Si, ¹³C-NMR and FT-Raman spectroscopy. The oxygen barrier properties of the hybrid polymers were found to be strongly influenced by the inorganic and also by the organic network density. In order to scale-up the excellent laboratory results to pilot plant and production dimensions additional efforts were necessary. For optimization of the barrier coating compositions the influence of the starting compounds on the resulting barrier properties had to be investigated. A constant quality of the coating sols during the industrial processing had to be guaranteed so as to obtain reproducible barrier properties. The influence of storage conditions on chemical reactions in the coating sols, indicated by changes of viscosity, was investigated. Since the curing times of the laboratory system were not transferable to the high speed of the production roll coating process more effective curing methods had to be found. The influence of the storage time of the cured coating materials on the oxygen barrier properties was investigated. Even by storing at ambient temperature further improvement of the oxygen barrier properties was obtained. Only by optimizing all of the above mentioned parameters can the excellent barrier properties result in marketable products.     

溶胶-凝胶法制备光固化聚氨酯丙烯酸酯杂化材料的研究

以溶胶-凝肢法制备的硅溶胶为无机相,聚氨酯丙烯酸酯为有机相,以γ-甲基丙烽酰氧丙基三甲氧基硅烷(TMSPM)为两相间的偶联剂,制得了光固化杂化材料。研究了未固化的杂化体系的稳定性问题,并对其进行了结构表征和性能研究。无机相与有机相通过共价键相连。使得杂化体系光固化膜高硬度的获得并没有以柔韧性的损失为代价。在无机物含量较低时,聚氨酯丙烯酸酯／二氧化硅杂化体系先固化膜的耐磨性略有提高。     

Effect of monomer structures and preparation methods on the morphology and properties of UV cured organic–inorganic hybrid films

The effects of preparation methods and monomer chemical structures on the microstructure, morphology, and properties of the hybrid films were studied. 7DBPA‐3S was synthesized by the sol–gel reaction of precondensed silica particles with alkoxysilane‐modified polymers DBPA. DBP‐POBG3T3 was prepared by the radiation curing of comb‐like UV curable alkoxysilanes POBG3T3 with UV curable polymer DBP, followed by the sol–gel reaction of alkoxysilanes. The DBP‐POBG3T3 film consisted of polymer matrix and large tethered aggregates with tiny silica connected by organic chains. On the contrary, silica nanoparticles were well‐dispersed in the 7DBPA‐3S hybrid film. The TEM, energy dispersive X‐ray Si‐mapping and P‐mapping images are good experimental approaches to characterize the texture of the tethered aggregates. The 7DBPA‐3S hybrid composite with well‐dispersed silica nanoparticles exhibited smoother surface, higher transparency, and better thermal stability than the DBP‐POBG3T3 composite did. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1152–1165, 2007     

Development of Passive and Active Barrier Coatings on the Basis of Inorganic–Organic Polymers

Summary. With a new kind of barrier coating material, namely inorganic–organic polymers, it is possible to obtain excellent barrier properties against oxygen, water vapor, and flavor permeation. These hybrid polymers can be synthesized by the sol–gel technique. If extremely low permeation values are needed, the combination of hybrid polymer coatings with thin inorganic oxidic layers (SiO_x, AlO_x) is very effective and leads to permeation values for oxygen and water vapor below 10⁻³ cm³/m² · d · bar or g/m² · d. These passive barrier layers can be further improved by the combination with active oxygen barrier layers which have been developed for the food packaging industry. This approach makes these multilayer laminates promising candidates for special applications in the food packaging industry as well as for sophisticated applications in technical areas: the encapsulation of sensitive organic devices like solar cells, organic light emitting diodes, or polymer electronic systems.     

Grafting of cellulose by ring-opening polymerisation – A review

In this review, homogeneous and heterogeneous grafting from cellulose and cellulose derivatives by ring-opening polymerisation (ROP) are reported. Cellulose is biorenewable and biodegradable as well as a stiff material with a relatively low specific weight, foreseen to be an excellent replacement for synthetic materials. By utilising ROP of monomers such as ε-caprolactone or l-lactide from cellulose, composite materials with new and/or improved properties can be obtained. Grafting of solid cellulose substrates, such as cotton, microfibrillated cellulose (MFC) or cellulose nanocrystals, renders cellulose that can easily be dispersed into polymer matrices and may be used as reinforcing elements to improve mechanical and/or barrier properties of biocomposites. A surface grafted polymer can also tailor the interfacial properties between a matrix and the fibrillar structure of cellulose. When derivatives of cellulose are grafted with polymers in homogenous media, amphiphilic materials with interesting properties can be achieved, anticipated to be utilised for applications such as encapsulation and release.     

Inorganic-Organic Polymers with Barrier Properties for Water Vapor,Oxygen and Flavors

With a new kind of barrier coating material, inorganic-organic polymers, it is possible to obtain high-barrier properties with respect to the permeation rates of oxygen, water vapor and volatile organic compounds.The hybrid polymers are accessible via the sol-gel technique. The inorganic network is formed as a result of controlled hydrolysis and condensation of alkoxysilanes, organoalkoxysilanes, acryloxysilanes or metal alcoholates. The organic network results from subsequent thermal or UV-induced polymerization of organo-functional groups.Due to the control of the inorganic and organic network densities and the insertion of specific functional groups to control the polarity of the resulting material, it was possible to develop high-barrier coatings with excellent adhesion properties on a wide variety of polymer films.These high-barrier coatings are also suitable as adhesives which can be used in laminates. The properties of the processable multilayer structures are preserved to a much higher extent than with other comparable, commercially available materials even under high mechanical and thermal stress and storage in humidity.     

可紫外光固化的超支化聚硅氧烷合成及固化研究

同线型聚硅氧烷聚合物相比，超支化聚硅氧烷聚合物具有低粘度、高反应活性和良好的相容性等特点，其中以制备超支化的聚硅氧烷基硅氧烷和聚烷氧基硅氧烷为主．对于超支化聚硅氧烷主要是以ABx（X=2～6）（其中A为双键，B为硅氢键）型单体为原料，在氯铂酸或Pt／C的催化下，通过硅氢加成反应一步制备，最终聚合物的端基（B）为硅氢键，而双键则完全反应，此外也可通过含不同数目烷氧基硅烷的水解缩合制备超支化聚硅氧烷．     

Oxygen Inhibition and Coating Thickness Effects on Uv Radiation Curing of Weatherfast Clearcoats Studied by Photo-DSC

Radiation curing is an environmentally-friendly technology. Furthermore, radiation curing is a faster, energy saving and more efficient industrial process than the heat-curable process. One of the most important requirements for the widespread application of UV curable coatings in the coating industry is that they are stable vs. atmospheric degradation. Today's state of the art in oxidative drying and thermosetting coatings is the use of light stabilizers to protect polymers vs. the damage of outdoor exposure. Oxygen has a detrimental effect on the cure response of free radical systems, especially in thin-film coatings. Differential photocalorimetry (photo-DSC) was used to investigate the oxygen effect and the use of light stabilizers on UV curing of photocurable formulations based on acrylate materials. Coating thickness influence was also considered. This revised version was published online in August 2006 with corrections to the Cover Date.     

原位探测防污高分子材料与液体界面的分子结构

Marine organisms such as plants, algae or small animals can adhere to surfaces of materials that are submerged in ocean. The accumulation of these organisms on surfaces is a marine biofouling process that has considerable adverse effects. Marine biofouling on ship hulls can cause severe fuel consumption increase. Investigations on antifouling polymers are therefore becoming important research topics for marine vessel operations. Antifouling polymers can be applied as coating layers on the ship hull, protecting it against the settlement and growth of sea organisms. Polyethylene glycol (PEG) is a hydrophilic polymer that can effectively resist the accumulation of marine organisms. PEG-based antifouling coatings have therefore been extensively researched and developed. However, the inferior stability of PEG makes it subject to degradation, rendering it ineffective for long-term services. Zwitterionic polymers have also emerged as promising antifouling materials in recent years. These polymers consist of both positively charged and negatively charged functional groups. Various zwitterionic polymers have been demonstrated to exhibit exceptional antifouling properties. Previously, surface characterizations of zwitterionic polymers have revealed that strong surface hydration is critical for their antifouling properties. In addition to these hydrophilic polymers, amphiphilic materials have also been developed as potential antifouling coatings. Both hydrophobic and hydrophilic functional groups are incorporated into the backbones or sidechains of these polymers. It has been demonstrated that the antifouling performance can be enhanced by precisely controlling the sequence of the hydrophobic-hydrophilic functionalities. Since biofouling generally occurs at the outer surface of the coatings, the antifouling properties of these coatings are closely related to their surface characteristics in water. Therefore, understanding of the surface molecular structures of antifouling materials is imperative for their future developments. In this review, we will summarize our recent advancements of antifouling material surface analysis using sum frequency generation (SFG) vibrational spectroscopy. SFG is a surface-sensitive technique which can provide molecular information of water and polymer structures at interfaces in situ in real time. The antifouling polymers we will review include zwitterionic polymer brushes, mixed charged polymers, and amphiphilic polypeptoids. Interfacial hydration studies of these polymers by SFG will be presented. The salt effect on antifouling polymer surface hydration will also be discussed. In addition, the interactions between antifouling materials and protein molecules as well as algae will be reviewed. The above research clearly established strong correlations between strong surface hydration and good antifouling properties. It also demonstrated that SFG is a powerful technique to provide molecular level understanding of polymer antifouling mechanisms.     

Progress in Synthetic Polymers Based on Natural Amino Acids

α-Amino acids are one type of the main building blocks of living systems, being the primary components of all naturally occurring peptides and proteins. They are the simplest optically active compound in the nature and have multiple functional groups, which enable them to be transformed into a wide variety of optically active substances. The resulting materials show a wide variety of functions such as electron transfer, information transfer, photo reactivity and selective catalytic function, which cannot be imitated by synthetic compounds. Functional macromolecular materials using biological chiral resources such as amino acids have been drawing much interest due to their biocompatibility and biodegradability easing the ecological trouble because amino acid residues can be targeted for cleaving by different enzymes. Also, this type of polymer contains nitrogen, which the organism needs for their growth and shows excellent hydrophilic character, reasonably high melting points and good materials properties even at relatively low molecular weights. However, polymers composed of amino acids alone have limited thermal stability and are insoluble in many common organic solvents, which make these materials difficult to fabricate and utilize. Preparation of hybrid systems between conventional synthetic polymers and linear sequences of amino acids are interesting because amino acid segments possess unique properties, such as directional polarity, chirality and their capability to undergo specific noncovalent interactions. These properties can potentially be used for designing novel hierarchical superstructures with tunable material properties for a wide variety of applications. Herein, the synthesis and properties of synthetic macromolecules having natural amino acids are reviewed in details up to now with excluding polypeptides.     

Eco-friendly elastomeric composites containing Sencha and Gun Powder green tea extracts

A permanent increase in the demand for polymers is closely related to the issue of their degradation. Typically, aromatic amines or phenol derivatives are used to protect materials against ageing. In our studies, we propose to use natural pro-ecological substances, such as polyphenols extracted from green tea leaves, to protect elastomers against ageing. Several extracts from Sencha and Gun Powder green tea leaves were incorporated into ethylene-propylene rubbers (EPM, Dutral CO-054). The vulcanizates of EPM samples containing the anti-oxidants under investigation were then subjected to UV radiations and climatic and thermal ageing processes. The changes in deformation energy, colour, and crosslinking density of the EPM vulcanizates were then measured before and after each ageing process. Based on the investigations performed, it is has been found that both the Sencha and Gun Powder green tea extracts display anti-oxidative properties that can protect EPM rubbers against the action of climatic factors.     

由聚合物门控的介孔二氧化硅基刺激响应性药物递送系统

本文主要介绍了以聚合物体系作为门控构筑的基于介孔二氧化硅纳米粒子的刺激响应性药物控释体系, 并根据聚合物类别将门控体系分为聚合物刷、 聚合物交联网络和聚合物包裹层三类. 根据聚合物“阀门”与无机纳米粒子的共价或非共价连接方式, 综述了这些杂化材料在不同外界刺激作用下的药物控制释放行为, 并给出该领域所面临的机遇和挑战.     

聚合物在受限层空间中的形态结构演变及相关性能研究进展

自然界中的层状有序结构如强韧的贝壳、树木等,往往带来优异的性能或特殊的功能。作为仿生材料学在高分子加工成型技术中的应用,聚合物微纳层共挤出技术是通过特殊的流道设计对聚合物熔体进行多次强制分割叠加,来制备高性能交替多层聚合物材料的新方法。层倍增器单元对熔体的多重力场作用,为多相多组分体系形态的原位调控提供了可能。而通过两相交替层状排布形成的受限层空间和丰富的层界面不仅赋予了材料独特的力学、光电、阻隔等性能,还为聚合物结晶调控提供了理想的研究模型。本文简要综述了近年来在层倍增过程中聚合物的形态结构演变及其对相关性能影响方面的研究进展。     

The maleimide modified epoxy resins for the preparation of UV‐curable hybrid coatings

In the present study, maleimide‐modified epoxide resin containing UV‐curable hybrid coating materials were prepared and coated on polycarbonate substrates in order to improve their surface properties. UV‐curable, bismaleimide‐modified aliphatic epoxy resin was prepared from N‐(p‐carboxyphenyl) maleimide (p‐CPMI) and cycloaliphatic epoxy (Cyracure‐6107) resin. The structure of the bismaleimide modified aliphatic epoxy resin was analyzed by FTIR and the characteristic absorption band for maleimide ring was clearly observed at 3100 cm^?1. Silica sol was prepared from tetraethylorthosilicate (TEOS) and methacryloxy propyl trimethoxysilane (MAPTMS) by sol–gel method. The coating formulations with different compositions were prepared from UV‐curable bismaleimide‐based epoxy oligomer and sol–gel mixture. The molecular structure of the hybrid coating material was analyzed by ²⁹Si‐CP/MAS NMR spectroscopy techniques. In the ²⁹Si CP/MAS NMR spectrum of the hybrid coating, mainly two kinds of signals were observed at ?68 and ?110 ppm that correspond to T³ and Q⁴ peaks, respectively. This result shows that a fully condensed structure was obtained. The thermal and morphological properties of these coatings materials were investigated by using TGA and SEM techniques. Hardness and abrasion resistance properties of coating materials were examined and both were found to increase with sol–gel precursor content of the coating. The photopolymerization kinetics was investigated by using RT‐IR. 70% conversion was attained with the addition of 15 wt% of BMI resin into the acrylate‐based coating formulation. It was found that the UV‐curable organic–inorganic hybrid coatings improved the surface properties of polycarbonate. Copyright © 2009 John Wiley & Sons, Ltd.     

Bulk plastic materials obtained from processing raw powders of renewable natural polymers via back pressure equal channel angular consolidation (BP-ECAC)

Renewable natural polymers wheat starch (WS) and wheat gluten (WG) were successfully processed into plastic bulk materials using back pressure equal channel angular consolidation (BP-ECAC) without using any additional plasticizers at relatively low temperatures. The strong shear deformation occurred during the process caused an effective deformation of WS or WG granular structures and resulted in an efficient gelatinization of starch or plasticization of gluten with the natural moisture content. Sufficient chain entanglement was formed in both WS and WG materials for achieving strong cohesion among the macromolecule matrixes. The mechanical strength of the obtained plastic materials was comparable to that of conventional polymers but stronger than the strength of thermoplastic WS or plasticized WG. The processing temperature played an important role in determination of morphologies and properties of the plastic materials. Increasing processing temperature would cause more effective gelatinization or plasticization of the natural polymers, enhance the interactions among different components in the systems, and form materials with improved mechanical properties. Thermal cross-linking might play a positive role in the improvement of mechanical properties when processing temperature was increased. However, thermal decomposition could also occur under such severe shearing especially at high temperatures. The optimum temperature for conducting such process was around 100-120 °C for WS and WG. The BP-ECAC method provides a potential to manufacture natural polymer based plastic materials efficiently on an industrial scale for various applications.     

Polystyrene-graft-polyglycerol resins: a new type of high-loading hybrid support for organic synthesis

The preparation of a dendritic graft polymer by a very efficient synthesis of polyglycerol directly on a polystyrene resin is presented. This one-step process can be performed on a multigram scale to provide a chemically stable polymeric support. The resulting hybrid polymers were fully characterized by diverse analytical methods (NMR, IR, ESEM, UV detection of cleaved protecting groups, and mass-spectrometric methods). They combine a high loading capacity (up to 4.3 mmol g(-1)) with good swelling properties in a wide range of solvents (including water), which is the major drawback for many existing solid phase supports. In comparison to the widely employed PEGylated resins, these hybrid materials offer a 10-fold higher loading capacity. Their suitability as supports for organic synthesis and for the immobilization of reagents has been demonstrated. These materials also swell in water, and consequently, it should be possible to use these new hybrid materials for synthesis in protic solvents.     

Some Factors Governing the Coating of Organic Polymers by Sol-Gel Derived Hybrid Materials

Organic-inorganic hybrid materials can exhibit some properties of organic polymers, such as toughness and elasticity, and/or that of ceramics, such as chemical stability and hardness. In this review, we discuss the main factors that should be considered when coating a polymeric substrate with a sol-gel derived organic-inorganic hybrid material. The effects of the solution characteristics, the polymer substrate chemistry and preparation, the application process and materials characteristics are considered. Examples of commercial and published systems are discussed. We find that due to the wide diversity of the systems investigated, it is difficult to be specific in recommending guidelines applicable to all systems. However, some general considerations can be made that should be useful in the design of functional hybrid coatings aimed at improving the characteristics of polymeric surfaces.     

Sol–gel derived organic–inorganic hybrid materials: synthesis,characterizations and applications

Organic/inorganic hybrid materials prepared by the sol–gel approach have rapidly become a fascinating new field of research in materials science. The explosion of activity in this area in the past decade has made tremendous progress in both the fundamental understanding of the sol–gel process and the development and applications of new organic/inorganic hybrid materials. Polymer-inorganic nanocomposite present an interesting approach to improve the separation properties of polymer material because they possess properties of both organic and inorganic such as good permeability, selectivity, mechanical strength, and thermal and chemical stability. Composite material derived by combining the sol–gel approach and organic polymers synthesis of hybrid material were the focus area of review It has also been demonstrated in this review that a more complete understanding of their structure–property behavior can be gained by employing many of the standard tools that are utilized for developing similar structure–property relationships of organic polymers. This review article is introductory in nature and gives introduction to composite materials/nanocomposite, their applications and the methods commonly employed for their synthesis and characterization. A brief literature survey on the polysaccharide templated and polysaccharide/protein dual templated synthesis of silica composite materials is also presented in this review article.     

Real Time Monitoring of Morphologic and Mechanical Properties of Polymer Nanocomposites During Extrusion by near Infrared and Ultrasonic Spectroscopy

Extrusion is one of the most applied technologies for the processing of polymer nanocomposites for applications in automotive, electrical and packaging industrial sectors. These nanostructured materials have advantages in comparison to traditional polymer materials, so that properties like tensile strength and modulus, barrier and surface properties, electrical properties and flame retardancy will be improved. There is a need to control amount and dispersion of the nanofillers in the polymer matrix during melt processing and to control the influence of the processing conditions on the nanocomposite formation. For an adequate real time characterization it is necessary to measure directly in the extruder. Spectroscopic methods and Ultrasonic measurements are outstanding methods for this kind of in-line monitoring. This paper deals with the real time determination of the dispersion and the impact strength of polymer nanocomposites in the melt during extrusion by Ultrasonic measurements and NIR spectroscopy. These in-line measurements were correlated with off-line rheological measurements, transmission electron microscopy and mechanical test measurements by multivariate data analysis. The polymers used are polypropylene and polyamide 6. As nanofillers we used different modified layered silicates. We determined the degree of exfoliation as an indicator for the dispersion of the nanofiller in the polymer matrix for different layered silicates and at different process conditions.