PP塑料底材处理剂的研制及应用

以氯化聚丙烯为主要原料,制备了一种环保型的聚丙烯塑料底材表面处理剂。讨论了树脂基料、溶剂、乳化剂的选取及配比等因素对涂层附着力的影响,确定了处理剂的最佳配方。经试验测试,聚丙烯塑料表面经处理剂处理后,其涂层的附着力显著提高。     

The effect of surface energetics and molecular interdiffusion on adhesion in multicomponent polymer systems

The interfacial region of coated plastics is an example of a multicomponent polymer system. Practical adhesion, as determined by the peel test, has been found to be strongly dependent on the composition of the system and the degree of interaction between its components. Several interactions are possible during the coating process of polypropylene (PP)/ethylenepropylene-diene-monomer (EPDM) blends with chlorinated polyolefin (primer) and polyurethane (PUR) paint. Wettability, a necessary but not sufficient condition alone for molecular interdiffusion, was found to be good in all cases. The lack of interfacial adhesion between PP and PUR and between EPDM and PUR was explained by high interfacial tensions calculated from surface energetics, which, in turn, were determined by contact angle and inverse gas chromatography (IGC) measurements. The improvement of interfacial adhesion between PUR and PP by chlorinated polyolefin was explained by acid-base interactions detected by IGC. The creation of surface topography by extraction of low molecular weight fractions during the coating process does not influence the adhesion. Molecular interdiffusion was shown to be facilitated by solvents.     

利用注射成型制造金属板／塑料宏观复合制件的方法

介绍了一种利用注射成型机将金属板成型、塑料注射成型和塑料与金属板的粘接融合为一体的制造金属板／塑料宏观复合制件的新工艺方法。论述了复合成型中塑料与金属板的粘接原理以及金属板表面处理的目的和塑料接枝极性单体的改性处理的作用，并以铝板为例进行了复合成型试验。     

UV-cured fluorinated coatings for plastics: effect of the photoinitiator and of the substrate filler on adhesion

A high-performance fluorinated acrylic coating, containing perfluoropolyether chains, was applied to polyethylene and polypropylene by means of the UV-curing technique. The conditions for a good adhesion onto the plastic substrates were studied. A chemical bonding between the cured network and both the substrates was achieved when the photopolymerization was performed in the presence of benzophenone as a photoinitiator: by hydrogen abstraction from the substrate, polymer radicals were formed and could then initiate the polymerization of the acrylic species; grafting experiments of hydroxyethylacrylate confirmed this mechanism. However, the grafting reaction did not take place when the plastic substrates contained carbon black as a filler, which acted as a radical scavenger. In this case, in fact the adhesion results are not good, similar to those obtained in presence of a cleavage-type photoinitiator.     

Diffusion of an adhesion promoter (chlorinated polypropylene) into polypropylene/ethylene–propylene copolymer (PP/EP) blends: method of quantification

The adhesion between an organic coating and a polymer substrate may depend on the diffusion of organic coating constituents into the substrate. The diffusion of chlorinated polypropylene (CPO) into polymer substrates was quantified by using radiolabelled CPO and monitoring its dissolution subsequent to its application. The CPO was ³H-radiolabelled by reduction with NaB³H₄ in tetrahydrofuran. The characterization of native and labelled CPO by size exclusion chromatography and differential scanning calorimetry showed that the reaction did not degrade the resin. Several substrates and CPO application conditions were used in order to create a wide range of CPO-substrate interfaces. The measurement of the progressive dissolution of radiolabelled CPO showed a clear-cut differentiation between the CPO bound by the substrate and the CPO simply deposited as a film, and provided a minimum estimation of the amount which was retained through macromolecular entanglement or diffusion. A larger amount of bound CPO was found in PP/EP than in PP, in agreement with a broader CPO concentration profile (several μm) at the surface of the former, as observed by ToF-SIMS imaging.     

Recycling of thermoplastic waste: Phase equilibrium in polystyrene-PVC-polyolefin solvent systems

The contribution of plastics to the total amount of waste produced is increasing significantly. Not only do plastics present disposal difficulties, but traditional disposal techniques constitute a waste of valuable resources. A process to recycle plastic waste economically would provide an attractive solution to both problems. Approximately 70 percent of the U.S. plastics production is comprised of only three families of plastics; polyethylene, PVC and polystyrene. Mixtures of these three polymers invariably have poor properties because of their thermodynamic incompatibility, so a recycle scheme will have to achieve separation into nearly pure components. A process is proposed which takes advantage of the thermodynamic incompatibility of polymers in solution to effect such a separation. The equilibration of a simulated waste mix containing 4 parts polyolefin (polyethylene and polypropylene), 1 part polystyrene and I part PVC was investigated in a variety of solvents at total polymer concentrations of up to 15 percent, in the temperature range 115 to 125°C, using differential refractometry. In an 85 percent xylene, 15 percent cyclohexanone solvent, the polyolefins (polypropylene and the various densities of polyethylene) coexisted in a single phase, but the three phases obtained—polyolefin, polystyrene and PVC—routinely contained 99 + percent pure polymer, indicating that excellent separations of the major thermoplastic components of a waste mix can indeed be obtained.     

Studies on polymer blend of nylon 6 and polypropylene or nylon 6 and polystyrene using the reaction of polymer

In the presence of maleic anhydride-grafted polypropylene, marked dispersibility of the polymer blend of isotactic polypropylene and nylon 6 was obtained. This appeared to be caused by the formation of a certain graft polymer between maleic anhydride in polypropylene and terminal amino groups of nylon 6. The same phenomenon was observed when polystyrene and nylon 6 were blended with styrene–methacrylic acid copolymer as the interpolymer. The existence of such a graft polymer was confirmed by solvent extraction, estimation of the amino group of nylon 6, and identification by differential scanning calorimetry. The physical properties, especially mechanical properties of nylon 6–polypropylene polymer blends, were remarkably improved with increase of maleic anhydride added to the polymer blend. On the other hand, the physical properties those of nylon 6–polystyrene polymer blends were very little improved even in the presence of good dispersibility.     

Adhesion phenomena in (co)extrusion coating of paper and paperboard

In extrusion coating, the inadequate adhesion between the polymer coating and the fiber-based paper substrate (paper and paperboard) is both a common and a constant problem. The lack of adhesion between the printing ink, or glue, and the polymer coating is another area where adhesion improvement is needed. The common means of improving adhesion are flame, corona, and ozone treatments. A modem extrusion coating line is equipped with both a pretreatment and a post-treatment unit. From the work presented here, the following observations were made. The higher the applied corona power and the thicker the coating, the higher the surface energy and polarity of the low density polyethylene (PE-LD) surface. When a high corona power was applied to the coating, only the polar component of the surface energy was increased. The surface energy decreased sharply as a function of aging, but remained more or less constant after about 2 weeks' storage time. The contact angles of water on paper correlated well with the oxygen contents (determined by ESCA) and with the applied corona power. The polarities of both paper and paperboard increased as a function of the applied corona power. Corona pretreatment of paper and paperboard improved their adhesion to PE-LD remarkably. The adhesion of the polypropylene (PP) homopolymer is based more on mechanical interlocking than on interfacial bonding. On the other hand, the oxidizing pretreatments of the paper substrates significantly promoted the adhesion of the PP copolymer.     

Barrier properties of plasma-modified polypropylene and polyethyleneterephthalate

Plasma treatment changes the solvent absorption and permeation as well as the swelling properties of polymers. Enchanced solvent absorption and swelling are effects of an improved solvent compatibility. The plasma introduces a large number of different groups at the polymer surface depending on the nature of the plasma. Fluorine-containing plasmas can replace hydrogen atoms of the polymer molecule with fluorine atoms. Moreover, fluorine-containing plasma polymer layers can be formed. All these processes reduce the resulting surface free energy, reduce the diffusion length of solvent molecules, and produce a barrier layer. We have studied the formation of solvent barriers by plasma fluorination and by crosslinking by ultraviolet (UV) radiation. Thin foils of polypropylene (PP) and polyethyleneterephthalate (PET) were used as substrates. CF₄, SF₆, and SOF₂ were applied as sources of fluorine atoms. Hexafluoropropene, tetrafluorethylene, and perfluorohexylethylene form plasma polymer layers on the polymer substrates. Test solvents were n-pentane, tetrachloroethylene, dimethylsulfoxide, and mixtures of n-pentane and methanol. The permeation rate of solvents through plasma-modified polymers was measured gravimetrically. Mass spectrometry was applied to analyze the permeating components of the solvent mixtures. Fluorination of surface layers by plasma-chemical (CF₄, SF₆) means considerably reduces the permeation rate of PP (95% barrier effect) and PET (100%). The preferred permeation of one component of the pentane/methanol mixture is influenced by the polarity of plasma-introduced groups at the polymer surface.     

Reliable surface modification of dental plastic substrates to reduce biofouling with a photoreactive phospholipid polymer

Plastic substrates have been widely applied in clinical settings for dental treatments. These substrates should be strong enough for long‐term implantation in the oral cavity and should be resistant to biofouling. We developed a new photoreactive phospholipid polymer to reduce biofouling on dental plastics via a photochemical reaction. Poly(methyl methacrylate) (PMMA) and poly(ether ether ketone) (PEEK) were used as dental plastics. To determine the antibiofouling properties on the polymer surface, the phospholipid polymer was covalently immobilized on the substrates by UV irradiation. We evaluated the antibiofouling properties by observing the protein adsorption and cell and bacterial adhesion. Significant protein adsorption and cell adhesion appeared on the bare PMMA and PEEK substrates but decreased dramatically after surface modification with the phospholipid polymer. Thus, this photoreactive polymer shows potential for conferring dental plastics with antibiofouling properties. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46512.     

Enhancement of electrical and thermal conductivity of polypropylene by graphene nanoplatelets

One of disadvantages of polymer composites is poor electrical and thermal conductivity. As a first step in this direction, graphene‐modified polypropylene polymer is being developed to improve its electrical and thermal conductivity. Two techniques were investigated: surface coating and extrusion. In the case of coating technique, the percolation threshold was found to be 0.5 wt % of graphene and electrical conductivity of polypropylene increased around 13 log cycles. Coating technique breaks the agglomerations due to magnetic stirring followed by sonication and gives homogeneous graphene‐coated polypropylene pellets. When polymer melts under compression molding, the graphene platelets network formed on the surface of polypropylene pellets as well as through‐the‐thickness of the molded disk, which provide continuous network of graphene. However, in extrusion technique, graphene segregated and did not disperse properly in polypropylene. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45833.     

Atmospheric Pressure Plasma Polymerised Primer to Promote Adhesion of Silicones

By combining a liquid primer and a plasma jet system, a new route to improved adhesion on various substrates has been developed. The liquid primer is introduced as an aerosol into a plasma jet and the resultant active species are deposited as a polymer coating on adjacent surfaces. Careful control of the plasma parameters produced a dry polymerised coating with functional chemistry designed to enhance the adhesion of silicone sealants to two substrates. This paper describes the surface chemistry and adhesion properties of various coatings on both a plastic and a metal substrate. Selected surface analysis techniques were coupled to both wet and dry adhesion testing to characterise the factors that control adhesion within the system. Mechanical testing indicates that adhesion was improved by several orders of magnitude.     

Product design with glass fiber reinforced polymer blends,with potential applications in recycling

This paper addresses the issue of compositional variation in multiphase, multi-component polymer mixtures equivalent to those found in commingled waste streams, such as those obtained from reclamation/recycling operations of post-consumer containers. By using virgin resins, the effects of variations in the composition of matrices containing high density polyethylene (HDPE) as the major phase on the properties of composites containing varying amounts of glass fiber and different adhesion promoters are studied. The results obtained on injection molded thin-section parts indicate that it is possible, through the addition of glass fibers and in the presence of suitable adhesion promoters, to obtain enhanced and reproducible properties with relatively little dependence on matrix composition. Preliminary structural and flow analyses were performed with commercial software on different types of plastic parts that could be eventually molded from actual mixed waste plastics suitably modified through glass reinforcement. Experimentally generated rheological and mechanical property data on HDPE based blends containing 20 wt% glass fibers and different adhesion promoters were used for the simulation. Issues concerned with injection molding and product performance of glass-fiber reinforced blends are discussed.     

Optical and surface properties of whey protein isolate coatings on plastic films as influenced by substrate,protein concentration,and plasticizer type

Composite film structures of common plastic polymers including polypropylene (PP) or poly(vinyl chloride) (PVC) with whey protein isolate (WPI) coatings may be obtained by a casting method. Optical and surface properties of the resulting WPI‐coated plastic films, as affected by protein concentration and plasticizer type, were investigated to examine the biopolymer coating effects on surface modification with polymeric substrates of opposite polarity. The measured properties involved specular gloss, color, contact angle, and critical surface energy. Regardless of the substrates, WPI‐coated films possessed excellent gloss and no color, as well as good adhesion between the coating and the substrate when an appropriate plasticizer was added to the coating formulations. The protein concentration did not significantly affect gloss of WPI‐coated plastic films. Among five plasticizers applied, sucrose conferred the most highly reflective and homogeneous surfaces to the coated films. The WPI coatings were very transparent and the coated films with various protein concentrations and plasticizers showed no noticeable changes in color. Experimental results suggest that WPI coatings formulated with a proper plasticizer can improve the visual characteristics of the polymeric substrate and enhance water wettability of the coated plastic films. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 335–343, 2004     

Vapor phase photografting of methyl methacrylate on polymer films: Accelerating effects of solvent mixed with monomer

The effects of solvent mixed with monomer on benzopheneone-sensitized photografting of methyl methacrylate on polymer films were investigated in vapor phase at 60°C. The grafting on nylon 6 film was promoted by adding a pertinent quantity of solvent, such as phenol, m-cresol, benzyl alcohol, and formic acid, to the monomer. The similar effects accelerating the grafting on polyester film were observed for solvent, such as m-cresol, phenol, o-chlorophenol, and nitrobenzene. Such an accelerating function of the solvents is supposed to originate in the swelling of the film substrates due to solvents. On the other hand, solvents such as n-decane, decalin, and p-xylene retarded the grafting on low density polyethylene and polypropylene films. The differences in the solvent effects by the types of film substrates are discussed in terms of photoinduced radicals on the substrates containing solvents.     

PP塑料表面涂料的研制

用氯化聚丙烯(CPP)、附着力促进剂(C)、热塑性丙烯酸树脂(BS)等原料制出PP塑料用涂料,并对所用的溶剂、反应过程、操作条件和结果作了较为详细的叙述。     

Interfacial factors in corrosion protection: an EIS study of model systems

The effects of the liquid–coating interface and coating–metal interfaces on corrosion protection of a coated aluminum sheet (Alclad 7075-T6) were investigated using electrochemical impedance spectroscopy (EIS) of selected model systems. Parylene C was deposited on a solvent-cleaned aluminum sheet to prepare the coated aluminum sheet. Parylene C does not adhere well to most smooth surfaces: a freestanding film can easily be peeled off the substrate, although it does not peel off by itself during EIS measurements. When an ultra-thin layer of plasma polymer (ca. 50 nm) is deposited on the substrate, however, Parylene C adheres very strongly to the sheet. The top surface of Parylene C coating was modified via deposition of an ultra-thin layer of either a very hydrophobic or a very hydrophilic plasma polymer. The EIS Bode plot for the first run showed a typical good barrier coating regardless of the nature of the two interfaces under consideration. However, it was found that the impedance value in the lower frequency region decreases with increased immersion time, and the time-dependent change is greatly influenced by the nature of the two interfaces. A hydrophilic top surface increased the rate of time-dependent change, while good adhesion of Parylene C to the metal decreased the extent of time-dependent change. With a hydrophobic top surface and good adhesion to the substrate, EIS characteristics of a Parylene C coated sheet remained unaffected for 18 days (the longest time employed in this study). The decrease in impedance in the low frequency region converges to the Bode plot for a freestanding Parylene C film. The early decline of EIS characteristics can be correlated to the (pre-corrosion) micro-delamination of the coating.     

聚丙烯塑料涂料的制备与性能研究

利用接枝共聚反应合成了在聚丙稀塑料表面具有优异附着力的氯化聚丙烯改性树脂,对该树脂的结构、性能进行了讨论,同时对该树脂在聚两烯表面的附着机理进行了探讨。利用该氯化聚丙烯改性树脂配制的底面合一涂料,具有较好的综合性能,适合汽车等聚丙烯塑料件的涂装。     

A novel mucoadhesive polymer prepared by template polymerization of acrylic acid in the presence of poloxamer

A new mucoadhesive polymer was prepared by template polymerization of acrylic acid using poloxamer as a template polymer. FTIR results showed that the interpolymer complex was formed by hydrogen bonding between the carboxyl group of poly(acrylic acid) (PAA) and the ether group of poloxamer. The extent of hydrogen bonding in the PAA/poloxamer interpolymer complex increased as the ratio of PAA/poloxamer decreased. The T_g of PAA/poloxamer interpolymer complexes was matched well with the T_g calculated by Gordon‐Taylor's equation than that of their blends. This result suggests that the PAA and poloxamer in the interpolymer complexes are more compatible than their blends. The dissolution rate of PAA/poloxamer interpolymer complexes was much slower than that of their blends, and was dependent on the pH of the medium and the ratio of PAA/poloxamer. The adhesive bond strength of PAA/poloxamer interpolymer complexes to a plastic (polypropylene) plate was greater than their blends or a commercial product, Carbopol 971P NF. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1525–1530, 2001     

Dissolution of polypropylene in organic solvents: 1. Partial dissolution

The dissolution of polypropylene in organic solvents has been investigated in detail. The complete study will provide an interesting comparison with the literature concerning the dissolution of amorphous polymers. Under appropriate conditions polypropylene dissolves at a steady rate, but there is a preliminary induction period. The results reported here concern this period, and provide the foundation for later parts of the work. It was necessary to study solvent sorption by polymer as well as the partial or fractional dissolution characteristic of the induction period. The Hildebrand solubility parameter proved useful in understanding the behaviour of polypropylene soaked in various solvents over a range of temperatures. Factors controlling the partial dissolution have been identified and analysed.