Synthesis of comb-type amphiphilic graft copolymers derived from chlorinated poly(ɛ-caprolactone) via click reaction

This work refers to the synthesis of a series of novel chlorinated poly(?-caprolactone) (PCL) for further functionalization of PCL. For this aim, chlorine gas was passed through into the chloroform solution to obtain chlorinated polycaprolactone. The chlorine contents in chlorinated PCL were between 0.9 and 1.6 mol%. The molecular weights of the polymers (M _n) changed from 4853 to 9497 g/mol. As the amount of passing chlorine gas increases, the molecular weight of the chlorinated PCL was found to decrease. Pendant chloride groups of PCL were reacted with sodium azide to prepare PCL with pendant azide groups (PCL-N₃). Poly-(ethylene glycol) methyl ether (mPEG) was reacted with propargyl chloride to achieve alkynyl mPEG (mPEG-alkyn). Click reaction was then carried out by the reaction between PCL-N₃ and mPEG-alkyn to obtain PCL-g-PEG comb-type amphiphilic graft copolymer. Interestingly, SEM images of the PCL-g-PEG comb-type amphiphilic graft copolymers showed the highly microporous structure. The resulting products were characterized by ¹H NMR, FT-IR, gel-permeation chromatography, SEM, surface tension, contact angle and water uptake measurements, differential scanning calorimeter and thermogravimetric analyses techniques.     

Electrothermal fluidized bed chlorination of zircon

Zircon sand, ZrSiO₄, is chlorinated in an electrothermally-heated fluidized bed reactor using calcined petroleum coke as the reducing agent and chlorine as the chlorinating agent. The electrothermally-heated fluidized bed reactor proved to be versatile and effective for the chlorination of zircon sand. The rate of the reaction can be expressed by the formula The reaction was found to be of zero order with respect to the chlorine concentration, which suggests that chlorine is strongly adsorbed on the solid particles; as such, the concentration of chlorine in the gas phase has no effect on the reaction rate. The activation energy for the reaction was found to be 10.55 Kcal/gram mole which is indicative of control by the rate of a surface reaction or adsorption step.     

混合溶剂法生产氯磺化聚乙烯实验初探

将高密度聚乙烯（HDPE）树脂溶于混合溶剂中,以偶氮二异丁腈为引发剂,在装有搅拌的搪玻璃反应釜中用氯气进行氯化,用氯气和二氧化硫的混合气体进行氯磺酰化反应后制得氯磺化聚乙烯（CSM）溶液,经后部凝聚、挤压脱水后生产氯磺化聚乙烯。通过实验过程中的数据积累,掌握实验过程中的一些特殊现象,并且对异常现象加以分析和解决,为下一步装置改造创造条件。     

Immobilization of poly(ethylene oxide) on poly(ethylene terephthalate) using a plasma polymerization process

Poly(ethylene oxide) (PEO) has been covalently immobilized on poly(ethylene terephthalate) (PET) films using a radio frequency glow discharge polymer deposition process, followed by chemical coupling. Amino or hydroxyl groups were introduced onto the surface of the PET by exposing the films to allylamine and allyl alcohol plasmas. These functional groups were activated with cyanuric chloride, and then they were reacted with PEO. ESCA and water contact angle studies were used to characterize the surfaces of these films during the different stages of the reaction. The films containing the higher molecular weight PEO exhibited an increase in the ? C? O? peak of the C_ls ESCA spectrum and an increase in oxygen content on the film surfaces. Increasing the molecular weight of the PEO attached to the PET also resulted in an increased wettability of the films.     

Study of poly(vinyl chloride) blends with solid‐state chlorinated polyethylene

The influence of solid‐state chlorinated polyethylene of various chlorine content and residual crystallinity on the mechanical properties of rigid poly(vinyl chloride) has been studied. The impact strength of poly(vinyl chloride) was found to increase significantly as 10–20 mass% chlorinated polyethylene, containing from 10.2 to 27.3% chlorine content (preferably 21.8% Cl) were added. This dependence corresponded to the higher elasticity and impact strength of the solid‐state chlorinated polyethylene with chlorine content below 30% as well as the microstructure of its chlorinated block fragments. Multicomponent system of high impact strength and good flowability, consisting of poly(vinyl chloride), chlorinated polyethylene, hydroxyl‐terminated polybutadiene, and ethylene–propylene–ethylidenenorbornene terpolymer was also obtained. Regardless of the incompatibility between the polymer components of this blend, the similarity in the chemical nature of poly(vinyl chloride) and chlorinated polyethylene blocks on one hand, and the methylene sequences in the chlorinated polyethylene and elastomers on the other, resulted in the formation of an efficient interfacial layer. The changes in the structure of the blends were established by both calorimetric and microscopic studies. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2602–2613, 2006     

Synthesis and properties of green sustainable carbonate-type nonionics containing polyoxyethylene chains

A series of polyoxyethylene surfactants containing carbonate linkages as biodegradable and chemically recyclable segments was designed and synthesized by a green process. A two-step carbonate exchange reaction was used: dimethyl or diphenyl carbonate was reacted with 1-alkanol, and the product was reacted with poly (ethylene) glycol in the presence of a lipase or chemical catalyst. The obtained carbonate-type nonionics exhibited good surface-active properties such as a low critical micelle concentration value and a surface tension lowering action. They were readily biodegraded by activated sludge, furthermore, could be chemical recycled using a lipase.     

Adhesion modification of polyolefin surfaces with sodium hypochlorite in acidic media

Increased surface adhesiveness of HDPE is achieved by immersing it in an aqueous solution of sodium hypochlorite (bleach) mixed with an acid. This process results in the addition of functionality to the polymer surface vastly altering its adhesive, polarity and surface reactivity. Analysis of the modified polymer surfaces by ESCA has shown that chlorine atoms have been added to the surface. Studies regarding the chlorination of small molecules have also shown that the chlorination process is amenable to a variety of chlorination objectives and offers a route toward the functionalization of a variety of polymeric and non-polymeric substrates. In particular, this treatment renders unpaintable substrates such as HDPE more receptive to application of paints and adhesives. In this paper, we report the results of paint adhesion studies on treated polymer surfaces.     

Modification of Silica Nanoparticles with Miktoarm Polymer Brushes via ATRP

Silica nanoparticles were successfully modified with miktoarm brushes via atom transfer radical polymerization (ATRP) using three different approaches. In the first approach: “graft onto and from”, a poly(tert-butyl acrylate) (PtBA) macroinitiator was grafted onto the surface of a monomer-modified silica nanoparticle. Then, polystyrene (PSt) brush was grafted from the surface-tethered reactive chain end. In the second approach: “two-step reverse ATRP”, the PtBA and poly(n-butyl acrylate) (PBA) brushes were consecutively grafted from initiator-modified silica particles via ATRP. The polymerization was initiated from the silica surface via a two-step controlled thermal decomposition of surface-tethered diazo initiator moieties. In the third method: “diblock first”, a diblock copolymer of poly(tert-butyl acrylate) and poly(glycidyl methacrylate) (PtBA-b-PGMA) was grafted onto amine-modified silica particles. The diblock copolymer was covalently attached to the silica surface via interaction between surface-tethered amine groups and the short reactive block containing glycidyl groups. Next, the polystyrene brushes were grafted from surface-tethered reactive chain end. The materials prepared by three different approaches were characterized using gel permeation chromatography (GPC) and thermogravimetric analysis (TGA). The PtBA brushes were hydrolyzed under acidic conditions to form poly(acrylic acid) (PAA) brushes. The resulting materials were imaged using atomic force microscopy (AFM) and transmission electron microscopy (TEM).     

Miscibility in poly(vinyl chloride)/chlorinated poly(vinyl chloride) blends,and blends of different chlorinated poly(vinyl chlorides)

Blends of poly(vinyl chloride) with chlorinated poly(vinyl chloride) (PVC), and blends of different chlorinated poly(vinyl chlorides) (CPVC) provide an opportunity to examine systematically the effect that small changes in chemical structure have on polymer-polymer miscibility. Phase diagrams of PVC/CPVC blends have been determined for CPVC's containing 62 to 38 percent chlorine. The characteristics of binary blends of CPVC's of different chlorine contents have also been examined using differential calorimetry (DSC) and transmission electron microscopy. Their mutual solubility has been found to be very sensitive to their differences in mole percent CCl₂ groups and degree of chlorination. In metastable binary blends of CPVC's possessing single glass transition temperatures (T_g) the rate of phase separation, as followed by DSC, was found to be relatively slow at temperatures 45 to 65° above the T_g of the blend.     

How do chlorinated poly(olefins) promote adhesion of coatings to poly(propylene)?

The mechanism by which chlorinated poly(olefin) (CPO) primer coatings promote adhesion of paints to poly(propylene) and thermoplastic poly(olefins) (TPO) has been examined by surface characterization techniques including electron spectroscopy for chemical analysis (ESCA), time-of-flight secondary ion mass spectrometry (ToFSIMS) and transmission electron microscopy (TEM). The coatings, their interfacial failures, and taper-cut cross sections were studied, using both waterborne and solventborne CPO primers. The results were then correlated with peel strength and crosshatch adhesion tests. CPO primers do not penetrate deeply into the poly(olefin) substrates, but are quite mobile following application of the topcoat. Solventborne CPO's generally showed adhesive failure at the CPO/poly(olefin) interface when dried at ambient temperatures. Test results are also reported for waterborne CPO adhesion promoters.     

Preparation and characterization of thermo-sensitive microspheres with β-cyclodextrin groups

采用沉淀聚合机理,由一步法和两步法制备聚（N-异丙基丙烯酰胺-甲基丙烯酸缩水甘油酯） [P(NIPAM-co-GMA)]温敏性微球。其中一步法是同时加入所有反应物反应成微球,而两步法是先加NIPAM成微球,再加入GMA,最终均生成P(NIPAM-co-GMA)微球;再将改性的乙二胺代环糊精（EDA-β-CD）通过化学反应引入到P(NIPAM-co-GMA)微球结构中,制备得到聚（N-异丙基丙烯酰胺-甲基丙烯酸-2-羟丙基乙二胺基环糊精） [P(NIPAM-co-GMA/β-CD)]共聚高分子微球。分别用扫描电镜、红外光谱、控温激光粒度仪及光学显微镜对产物的形貌、结构和温敏特性进行了表征。结果表明,两种方法制备的微球均具有良好的单分散性和球形度,均能成功地固载β-环糊精（β-CD）基团,并且都有温度响应特性;但是,同一步法制备的微球相比,两步法制得的微球粒径明显较大,且微球固载有更多的β-CD。     

Photografting of acrylic acid on high density polyethylene powder in vapour phase

A photografting technique was explored as a means of functionalizing high density polyethylene (HDPE) powder. The graft copolymerization reaction of acrylic acid on HDPE powder and the surface structure of grafted HDPE powder were studied in terms of grafting degree and grafting efficiency, and by FTIR and ESCA. The results show that the surface of chemically inert HDPE powder pretreated by an acetone solution of benzophenone (BP) can be graft‐copolymerized with acrylic acid by photografting in the vapour phase. Thereby, the grafting degree is increased but the grafting efficiency is decreased with increasing reaction time. When the BP concentration in pretreatment solution is increased, the grafting degree is increased to a maximum, and is then reduced. The most suitable reaction temperature is 90 °C. Grafting degree can reach the quite high value of 10.6 wt% under the conditions of BP concentration 1.0 wt%, reaction time 1 h and temperature 90 °C. © 2000 Society of Chemical Industry     

氯化原位接枝反应制备羟基官能化CPE力学性能研究

采用气-固相氯化原位接枝来实现对聚乙烯粉末的改性，将氯化和接枝过程合为一体，大大简化了接枝共聚物的合成过程，为含氯聚合物的改性提供了一个新的手段。以高密度聚乙烯（HDPE）为原料．采用氯化原位接枝法合成了以氯化聚乙烯（CPE）为骨架聚合物，丙烯酸-2-羟基乙酯（HEA）为支链的接枝聚合物，反应中不需要加入任何引发剂。探讨了影响接枝聚合物力学性能的因素及变化规律。实验结果表明接枝聚合物的力学性能较CPE有显著的提高。氯化接枝温度、聚合物氯含量以及HEA单体的加入量对CPE—g—HEA的力学性能有很大的影响。     

高氯化聚乙烯在防腐涂料中的应用研究

研究了固相法涂料用高氯化聚乙烯树脂的制备及其在防腐涂料中的应用。结果表明,适当降低原料高密度聚乙烯（ＨＤＰＥ）的分子量,产物高氯化聚乙烯（ＨＣＰＥ）树脂可直接用于涂料配制;调节ＨＤＰＥ的分子量及ＨＣＰＥ的氯含量,涂料粘度可在较大范围内变化。ＨＣＰＥ涂料的性能远优于过氯乙烯涂料而与氯化橡胶涂料相当,是替代氯化橡胶涂料的理想物质。     

Preparation of chlorinated poly(propylene carbonate) and its effects on the mechanical properties of poly(propylene carbonate)/starch blends as a compatibilizer

Polymer Bulletin - Poly(propylene carbonate) (PPC) was chemically modified by chlorine through water phase suspension chlorination reaction, and the product was named as chlorinated poly(propylene...     

Studies on grafting of methacrylic acid on to poly(vinyl chloride) films

The characterization of poly(vinyl chloride-g-methacrylic acid) (PVC-g-MAA) films, prepared by the simultaneous-irradiation technique, was undertaken through swelling measurements, attenuated total reflection infrared spectroscopy (ATRIR), scanning electron microscopy (SEM), electron spectroscopy for chemical analysis (ESCA) and thermogravimetric analysis (TGA). The per cent swelling of grafted PVC in various media increased with the increase in the graft level. A higher per cent swelling was observed in 0-5m NaOH aqueous solution relative to that in distilled water. It is concluded from the ATRIR and ESCA studies that the concentration ratio of oxygen to chlorine atoms on the surface of grafted PVC increased compared with unmodified PVC, indicating grafting of methacrylic acid on to the surface. It was also found that the thermal properties of PVC improved after grafting with methacrylic acid.     

The adhesive properties of chlorinated ultra-high molecular weight polyethylene

Ultra-high molecular weight polyethylene (UHMW-PE) is well known for its abrasion and chemical resistance. Recently we developed a new application for UHMW-PE as a liner in elastomeric hoses. It was found that the adhesion between UHMW-PE and elastomers such as ethylene-propylene-diene monomer (EPDM) and styrene-butadiene rubber (SBR) is sufficient for practical applications, but the adhesion to nitrile rubber (NBR) is poor. In order to improve the adhesion between NBR and the UHMW-PE liner, (nascent) powder chlorinated polyethylenes were used as interlayers between UHMW-PE and NBR. These powder chlorinated polyethylenes are polymers with a dual nature and are composed of highly chlorinated polyethylene segments compatible with NBR and polyethylene segments compatible with UHMW-PE. In order to achieve sufficient adhesion, the chlorine content of the chlorinated blocks should be at least 15 wt%. If these powder chlorinated UHMW-PEs have a chlorine content of 15 wt% in the chlorinated blocks, dilution with polyethylene hardly affects the adhesive properties, which is an advantage in the practical use of these materials as interlayers.     

新型气固相法CPVC制备工艺的研究

以经力化学改性的PVC树脂为原料,通过低温等离子体生成自由基Cl.,在气固流化床中制备CPVC,考察了输入电压、体系压力、氯气流量、反应时间、惰性气体等因素对CPVC氯含量的影响,讨论了反应体系温度的控制,并采用扫描电镜对CPVC产物进行了表征。结果表明:①经过力化学改性后的PVC树脂颗粒粒径有较大程度的减小,比表面积增大,且树脂皮膜和结晶区被破坏,有利于氯化反应;②较佳的制备工艺条件为输入电压900V,常压,氯气流量3L/min,反应时间30min,不加入氩气;③输入电压是影响CPVC氯含量的主要因素;④当CPVC的含氯质量分数超过68%后,反应速率快速下降;⑤试验制得的CPVC呈现疏松的不规则雪片状结构,初级粒子、聚集体、亚颗粒等多层次的结构已经完全消失,皮膜也被彻底破坏,比表面积较大。     

Reduction of perchlorate on rhodium and its specificity to surface crystallographic orientation

Catalytic properties of Rh(100), Rh(111) and polycrystalline rhodium electrodes in the process of perchlorate reduction in aqueous media have been studied. The reduction rates obtained under various conditions, as well as results of ultra-high vacuum (LEED, Auger) surface analyses of emersed Rh(100) surfaces, have provided evidence that surface chloride is the main reduction product. A temperature dependent chloride desorption has also been found via measurements of steady-state reduction currents and through chemical analysis of the electrolytic perchlorate solutions. The data demonstrate that under transient conditions, that is, when surface chloride formation determines the reaction rates, the reduction current decreases in the order: Rh(100) > Rh(poly) > Rh(111). Under steady-state conditions the rate order is: Rh(100) Rh(poly) > Rh(111). The reduction process is pH dependent and, as a prerequisite, requires a contact adsorption of perchlorate on the metal sites. Prospects for using rhodium as a catalyst or catalytic additive in electrocatalysis of inorganic species are discussed.On leave from the Department of Chemistry, Warsaw University, Warsaw, Poland.     

Semi-quantitative ESCA examination of coal and coal ash surfaces

Four North American coals and their ashes were examined using the direct, surface sensitive technique of X-ray photoelectron spectroscopy (ESCA). Two US National Bureau of Standards reference coals (SRM 1632a, SRM 1635) and one ash (SRM 1633a) were used for instrument calibration. These results verified the semi-quantitative nature of ESCA and its previously determined element detection level of ≈ 10^?9 gm cm^?2 of surface (≈0.1 bulk wt%). Thus, major elements and surface concentrated trace elements were detectable for these samples. ESCA detected elements present in the coal and/or ash in different chemical environments, for example sulphur as the sulphide or sulphate and carbon as graphite, carbonyl, carboxyl or hydrocarbon. The results of this preliminary study indicate that ESCA is useful to elucidate element siting within coal; information that is difficult to determine by analytical techniques requiring sample destruction prior to analysis. Several raw coals contained fluorine and chlorine near the one per cent level. Ashing effectively concentrates the mineral fraction of a coal by an order of magnitude resulting in additional elements being detected by ESCA. The resultant detection level of elements in the original coal is thus lowered to ≈0.01 bulk wt% by ashing. It was found that fluorine and sulphur were highly concentrated on several coal ash surfaces possible indicating surface Sorption reactions during combustion. Application of ESCA in coal geochemistry and mineralogy is indicated by this study. ESCA has the potential to measure elements at the minor and possibly trace level and confirm element siting within coal and coal ash. In addition, it may be possible to identify coals from different deposits by their unique broad scan ESCA spectra fingerprints.