光敏有机硅聚氨酯丙烯酸酯预聚体性能的研究

考查了光引发剂、活性单体对光敏有机硅聚氨酯丙烯酸酯预聚体（PSUA）胶膜的耐水性、拉伸强度、伸长率、硬度、柔韧性和热稳定性的影响。结果表明，胶膜具有优良的耐水性，吸水性低于4％。含单官能度单体的PSUA胶膜的接触角大于含多官能度单体的，含有IBOA的体系接触角达103．6°；当选择引发效率高的裂解型光引发剂，用量为0.5％～1％时，胶膜具有较高的接触角。含多官能度单体胶膜的拉伸强度高于含单官能度单体的体系，但伸长率较小。含TMPTA体系的胶膜的硬度最大，为0．575。胶膜具有较好的柔韧性和热稳定性，其柔韧性达到1mm级，在300℃时失重为4.61％。     

Preparation and characterization of printable solder resist inks based on hyperbranched polyester

Two novel solder resist inks containing hyperbranched epoxy resin (HBPE) for thermal curing and hyperbranched epoxy acrylate resin (HBPEA) for UV‐curing were introduced in this work. Different generations of HBPE and HBPEA were synthesized and their chemical structures were determined by FT‐IR. Both curing reactions were monitored under differential scanning calorimetry (DSC) and photo‐DSC. For HBPE, the curing temperature of 7th generation was only 91°C and for HBPEA, the curing duration of 7th generation was under 10 s. The thermal stabilities of cured resins were much more stable than linear resin, as the decomposition temperatures of HBPE and HBPEA were both over 400°C. The ink containing HBPE or HBPEA jetted by piezoelectric printer showed excellent accuracy and consistency of linewidth and the morphologies of cured pattern were observed through a stereo microscope. Other performances of solder masks were tested under China Printed Circuit Association (CPCA) standard (CPCA/JPCA 4306‐2011), which satisfy all requirements of printed circuit board soldering procedure. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41805.     

Synthesis of low viscosity,fast UV curing solder resist based on epoxy resin for ink‐jet printing

A novel photosensitive low viscosity epoxy resin was synthesized by polyethylene glycol (PEG)‐modified bisphenol‐A epoxy resin (E51). The resin was modified by ethylene glycol, diethylene glycol, and different molecule weights (200,300,400) PEGs to optimize the minimum viscosity. FTIR was used to determine molecule structure. Cationic photoinitiator (UVI‐6976) mixed with modified resin (10 wt %), was utilized to boost the resin curing under UV light. The curing degree was beyond 90% within 40 s and the whole process was monitored by photo‐DSC. The modified resin diluted with ethylene glycol diglycidyl ether, was screen printed onto polyimide and polyethylene terephthalate substrate, and the properties of solder mask were up to China printed circuit association standard. The solder resist also meet all requirements under ink‐jet printing technology as the viscosity is under 60 mPa·s and the curing duration is <1 min. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Positive‐working aqueous base developable photosensitive polybenzoxazole precursor/organoclay nanocomposites

Positive‐working aqueous base developable photosensitive polybenzoxazole (PBO) precursor/organoclay nanocomposites have been prepared through the addition of an organoclay to a PBO precursor. The organoclay was formed by a cation exchange reaction between a Na⁺‐montmorillonite clay and an ammonium salt of dodecylamine. The PBO precursor used in this study was a polyhydroxyamide that was prepared from a low‐temperature polymerization of 2′2′‐bis(3‐amino‐4‐hydroxyphenyl) hexafluoropropane and 4,4′‐oxydibenzoyl chloride with an inherent viscosity of 0.3 dL/g. The photosensitive resin/clay formulations were prepared from the precursor with 2,3,4‐tris(1‐oxo‐2‐diazonaphthoquinone‐5‐sulfonyloxy)‐benzophenone photosensitive compound and 3–5 wt % organoclay. The PBO precursor/clay was subsequently thermally cured to PBO/clay at 350°C. Both X‐ray diffraction and transmission electron microscope analyses showed that the organoclay was dispersed in the PBO matrix in a nanometer scale. The thermal expansion coefficient of PBO/clay film, which contained 5 wt % organoclay, was decreased 33% compared to the pure PBO film. The PBO/clay nanocomposite films also displayed higher thermal stability, glass transition temperature, and water resistance than the pure PBO film. The photosensitive PBO precursor/clay nanocomposite showed a line/space pattern with a resolution of 5 μm and its sensitivity and contrast were not affected by the organoclay. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2350–2356, 2005     

Study on benzoxazine-based film adhesive and its adhesion properties with CFPR composites

In this paper, a benzoxazine-based (BZ) adhesive with high temperature resistant was developed by blending benzoxazine monomer and tetrafonctional epoxy monomer as matrix modifier and polyetherimide as toughening agent. The results show that benzoxazine-based film adhesive could be cured at 190 °C, and the cured film adhesive exhibited high temperature resistance and a high glass transition temperature of 224 °C. The 5% weight loss temperature in air was 400 °C and the char yield in nitrogen at 800 °C was 48%. The cured film adhesive has good ablation resistance. The fabricated benzoxazine-based film adhesive has high adhesion reliability, with single-lap shear strength of 23.20, 28.36 and 20.04 MPa at room temperature, 140 and 175 °C respectively. The curing process of the film adhesive matches well with that of carbon fiber reinforced BZ prepreg and the film adhesive has stable adhesion properties. Its biggest advantage is that, during storage and transportation, there is no need of refrigeration. After 60 days of storage for benzoxazine-based film adhesive at room temperature, its process performance and adhesion properties remain unchanged. It is expected that the benzoxazine-based film adhesive can be used in aerospace, high-speed rail and other applications.     

Study on the liquid crystal display mask photo-curing of photosensitive resin reinforced with graphene oxide

Graphene oxide has the characteristics of high specific surface area, high strength, and high modulus. The tensile and compressive properties of the cured resin part can be reinforced after the graphene oxide is mixed into the photosensitive resin. A self-developed liquid crystal display (LCD) mask photo-curing machine is adopted to prepare photosensitive resin parts mixed with graphene oxide. The influence of graphene oxide content on the surface roughness, tensile, and compressive properties of the cured resin is analyzed by the combination of finite element simulation and experiment. It is concluded that the accumulation of graphene oxide is the main reason affecting the tensile and compressive properties of the cured part. By applying ultrasonic vibration and extending the time of magnetic stirring at 80°C, the dispersion uniformity of graphene oxide is improved, the agglomeration of graphene oxide is reduced, and the tensile and compressive strength of cured parts are strengthened.     

Synthesis and characterization of negative‐type polyamic acid ester with 1‐methacryloyloxy‐2‐propanoate group

A negative‐type photosensitive polyamic acid (PAA) was synthesized from cyclobutane‐1,2,3,4‐tetracarboxylic dianhydride and 2‐(methacryloyloxy)ethyl 3,5‐diaminobenzoate in N‐methyl‐2‐pyrrolidinone. Glycidyl methacrylate was added into the PAA solution to yield a photosensitive PAA ester (PAE) by the ring‐opening esterification reaction of the carboxylic acid group in the PAA and glycidyl methacrylate. Esterification reactions were conducted with varying reaction temperatures and times. The typical PAE (PAE‐C3) with a degree of esterification of 20% was used for a photosensitivity study. We investigated the effects of the postexposure baking temperature, amount of photoinitiator, and exposure dose on the photosensitivity of PAE‐C3. Furthermore, a photolithography evaluation was conducted on PAE‐C3 in the presence of 1‐[4‐(phenylthio)phenyl]‐2‐(O‐benzoyloxime)‐1,2‐octanedione as a photoinitiator using a mercury lamp at a 365‐nm wavelength. The resolution of the film with 2.0‐μm thickness was about 8 μm. PAE‐C3 cured at 250°C for 60 min was stable up to around 310°C in a nitrogen atmosphere. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2252–2258, 2006     

Impact of curing condition on pH and alkalinity/acidity of structural wood adhesives

Nine formulations were selected for evaluating the effect of different curing methods on pH and alkalinity or acidity of various structural wood adhesives. These included four phenol–formaldehyde (PF) resins with high pH, one phenol–resorcinol–formaldehyde (PRF) resin with intermediate pH, two melamine–urea–formaldehyde (MUF) resins, and two melamine–formaldehyde (MF) resins with low pH. The four curing methods used in the study were: (1) curing at 102–105°C for 1 h (based on CSA O112.6‐1977), (2) four‐hour curing at 66°C followed by 1‐hour curing at 150°C (based on ASTM D1583‐01), (3) curing at room temperature overnight (based on ASTM D 1583‐01), and (4) cured adhesive squeezed out from glue lines of bonded shear block samples. The effect of the different methods on pH and alkalinity/acidity of the cured adhesive depended strongly on the individual adhesives. For the PF, the alkalinity was different for the different formulations in the liquid form, while in the cured form, the difference in the alkalinity depended on the curing method used. The MF and the MUF were the adhesives most affected by the method used. In particular, the MUF showed much higher cured film pH values when cured by method 2 compared to the other three methods, while both the cured MF and MUF exhibited quite variable acidity values when cured with the different methods. The PRF showed reasonably uniform cured film pH but varying acidity values when cured with the different methods. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis of novolac‐type phenolic resins using glucose as the substitute for formaldehyde

Novel Novolac type phenolic resins were prepared using glucose as the substitute for toxic formaldehyde (a carcinogenic chemical). The resins were synthesized with varying molar ratios of phenol to glucose, catalyzed by strong acid (such as sulfuric acid) at 120–150°C. Analysis of the resins using gel permeation chromatography (GPC) and proton nuclear magnetic resonance (¹H‐NMR) showed that they were broadly distributed oligomers derived from the Fridel‐Crafts condensation of phenol and glucose. Using hexamethylenetetramine (HMTA) as the curing agent, the phenol‐glucose resins could be thermally cured and exhibited exothermic peaks at 130–180°C, typical of thermosetting phenolic resins. The cured resins showed satisfactory thermal stability, e.g., they started to decompose at >280°C with residual carbon yields of above 58% at 600°C. Based on the thermal properties, phenol‐glucose resin with a molar ratio of 1 : 0.5 is promising as it could be cured at a lower temperature (147°C) and exhibited a satisfactorily good thermal stability: it started to decompose at >300°C with a residual carbon yield of >64% at 600°C. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Polyethylene film as concrete curing material in a tropical climate

Concrete specimens were cast at and exposed to three different climatic regions in Ethiopia. The specimens were cured for different length of time, either covered with transparent polyethylene film, or by intermittent watering. At the end of the curing periods the specimens were stored at 20°C and 65% relative humidity until tested for compressive strength. Reference specimens were cast at 20°C and water cured, after 24 hours, for the next 6 days and finally stored at 20°C and 65% relative humidity. After 24 hours, the compressive strength of specimens exposed to the different climatic regions ranged from a high of 322% to a low of 77% of reference specimens, depending on the environmental conditions and type of curing media used. At higher ages, no deficiencies were observed from specimens cast at and exposed covered with polyethylene film. Others showed pronounced deficiencies.     

Synthesis and characterization of a positive‐working,aqueous‐base‐developable photosensitive polyimide precursor

A positive‐working, aqueous‐base‐developable photosensitive polyimide precursor based on poly(amic ester)‐bearing phenolic hydroxyl groups and a diazonaphthoquinone photosensitive compound was developed. The poly(amic ester) was prepared from a direct polymerization of 2,2′‐bis‐(3‐amino‐4‐hydroxyphenyl)hexafluoropropane and bis(n‐butyl)ester of pyromellitic acid in the presence of phenylphosphonic dichloride as an activator. Subsequently, the thermal imidization of the poly(amic ester) precursor at 300°C produced the corresponding polyimide. The inherent viscosity of the precursor polymer was 0.23 dL/g. The cyclized polyimide showed a glass‐transition temperature at 356°C and a 5% weight loss at 474°C in nitrogen. The structures of the precursor polymer and the fully cyclized polymer were characterized by Fourier transform infrared spectroscopy and ¹H‐NMR. The photosensitive polyimide precursor containing 25 wt % diazonaphthoquinone photoactive compound showed a sensitivity of 150 mJ/cm² and a contrast of 1.65 in a 3 μm film with 1.25 wt % tetramethylammonium hydroxide developer. A pattern with a resolution of 10 μm was obtained from this composition. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 352–358, 2002     

Dielectric characterization of relaxation and curing behavior of oriental lacquer

Dielectric analysis was used to investigate the effects of temperature and humidity on the curing behavior of oriental lacquer and to characterize the dielectric properties of the lacquer film. It was found that the oriental lacquer could not cure to its hardened state at relative humidity less than 50% in ambient temperature and that the cure time could be shortened tremendously by increasing the curing temperature. In order to study the dielectric properties of oriental lacquer film, two films were prepared at different curing temperatures. The glass transition and secondary relaxation temperatures of ordinary oriental lacquer film, room temperature cured purified lacquer, were observed at 45 and −40°C, respectively. The high temperature cured purified lacquer film showed a secondary relaxation at around −50°C. The relationship between thermodynamic properties and chemical structures was explored based on the analysis of the dielectric relaxation behavior using Cole–Cole plots and the dielectric relaxation intensity Δϵ. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1804–1810, 2000     

有机硅聚氨酯丙烯酸酯预聚物的合成

以异佛尔酮二异氰酸酯（IPDI）、烷羟基硅油（SD9134）和丙烯酸β-羟乙酯（HEA）为原料,合成了一种UV固化有机硅聚氨酯丙烯酸酯预聚物（PSUA）。探讨了原料、催化剂用量、反应温度等因素对反应的影响。确定最佳反应条件为：以烷羟基硅油SD9134和IPDI为主要原料,DBTDL为催化剂,其加入量为0．05％～0．1％,反应前3步在20～40℃下反应,第4步反应温度不超过70℃,并通过IR和GPC表征了PSUA的结构。     

Effect of curing behaviors on the properties of poly(arylene ether nitrile) end-capped with phthalonitrile

Poly(arylene ether nitrile) (PEN) end-capped with phthalonitrile (PEN-n) was synthesized by incorporating phthalonitrile into the terminals of PEN. The as-prepared flexible PEN-n (after elevated temperature treatment) was characterized by infrared spectroscopy, nuclear magnetic resonance, gel permeation chromatography, and rheological measurements. In addition, the effects of curing behaviors on properties of PEN-n films were studied by thermal, dielectric and mechanical measurements. Differential scanning calorimetry analysis showed that glass transition temperature of PEN-n was improved from 176 to 232°C as the curing temperature and time increased. Thermal gravimetric analysis revealed that initial decomposition temperature of PEN-n cured at 320°C for 2 h was 570°C. Mechanical properties showed that tensile strength of PEN-n uncured and cured at 320°C for 3 h was 85 and 97 MPa, respectively. The dielectric properties showed that the dielectric constant of PEN-n film decreased from 4.0 to 3.1 as the curing time increased and dielectric loss of PEN-n was 0.01 at 100 kHz. This kind of PEN-n film may be used as a good candidate for high-performance polymeric materials. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

A Novel Type of Organo Clay Containing Alkyd-Melamine Formaldehyde Resins

In this study, organo clay-modified alkyd resins were synthesized and these modified alkyd resins were cured with different ratios of melamine formaldehyde resin for the first time. Alkyd resins were blended with 30% and 40% of a commercial melamine-formaldehyde resin. Alkyd-melamine formaldehyde resin films were cured at 140°C for 2 h in an oven. The effect of organo clay addition on the physical and chemical film properties was investigated. These surface coating properties of the resins enhanced with amount of organo clay up to 2–3%. These resins are suitable for manufacturing of high-performance industrial baking enamels.     

Ethynyl aromatic siliconhybridized resin: Synthesis,characterizations, and thermal properties

A novel silicon‐containing resin (ESA resin) was successfully synthesized by the condensation reaction of lithium arylacetylide with chlorosilane in high yields. The resin was characterized by the techniques of FTIR, ¹H‐NMR, ²⁹Si‐NMR, and gel permeation chromatography. Thermal cure process was monitored by DSC and FTIR methods. This resin could melt at around 100°C and thermally cured at 200–250°C with low exothermal enthalpy. Owing to the high aryl groups containing and the complete crosslinking of ethynyl groups, the cured ESA resin exhibited excellent thermal stability and high char yield. The decomposition temperature $T_{d_5}$ of the cured resin was at 510°C, and the residue yield at 900°C was 82.9% in N₂. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Highly reflective polyimide films created by supercritical fluid infusion of a silver additive

Supercritical fluid infusion of a silver-containing additive [1,5-cyclooctadiene silver(I)-1,1,1,5,5,5-hexafluoroacetylacetonate] into a fully cured polyimide was achieved with moderately high-density carbon dioxide at 110°C for the first time. The polyimide was derived from 4,4′-oxydianiline and 3,3′,4,4′-benzophenone tetracarboxylic acid dianhydride. After infusion for approximately 60 min, the resulting film was then recured at 300°C in air. During this time, a silver mirror formed on both film surfaces. The nature of the silver and its distribution within the film and on the film surface were established via microscopy and surface analysis techniques. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 1309–1317, 1997     

Synthesis and characterization of hyperbranched photosensitive polysiloxane urethane acrylate

A novel hyperbranched photosensitive polysiloxane urethane acrylate (HBPSUA) based on hyperbranched polyesters (HBP-OH) has been synthesized. HBP-OH was synthesized from N,N-diethylol-3-amine methylpropionate as AB₂ monomer and trimethylolpropane (TMP) as a core molecule. The structure of the oligomer was characterized by FTIR, GPC and ¹H NMR. The molecular weight of the oligomer is about 10,000 and the viscosity is 4446 cps at room temperature. The HBPSUA possesses good compatibility with most of acrylate monomers. The effect of photoinitiators, monomers and light intensity on the photopolymerization kinetics of the oligomer HBPSUA was investigated by real-time infrared spectroscopy (RT-IR). The results show that HBPSUA can well photopolymerize under UV-irradiation in the presence of photoinitiators. Irgacure 1700 showed the highest initiating efficiency among those tested photoinitiators. The optimal concentration of photoinitiator (Darocur 1173) is determined as 0.05 wt.%. The system of HBPSUA/TPGDA has the high conversion of double bond and polymerization rate, and they are 92.38% and 22.25 s⁻¹, respectively. Compared with linear systems (PSUA), HBPSUA has the higher photopolymerization rate and lower viscosity. The cured film of HBPSUA possesses good flexibility.     

Synthesis and properties of novel poly(coumarin‐amide)s

A novel monomer diacid, 6,6′‐methylenebis(2‐oxo‐2H‐chromene‐3‐carboxylic acid), was synthesized and used in a direct polycondensation reaction with various aromatic diamines in N‐methyl‐2‐pyrrolidone solution containing dissolved LiCl and CaCl₂, using triphenyl phosphite and pyridine as condensing agents to give a series of novel heteroaromatic polyamides containing photosensitive coumarin groups in the main chain. Polyamide properties were investigated by DSC, TGA, GPC, wide‐angle X‐ray scattering, viscosity, and solubility measurements. The copolymers were soluble in aprotic polar solvents, and their inherent viscosities varied between 0.49 and 0.78 dL g^?1. The weight‐average and number‐average molecular weights, measured by gel permeation chromatography, were 27,500–43,900 g mol^?1 and 46,500–66,300 g mol^?1, respectively, and polydispersities in the range of 1.48–1.69. The aromatic polyamides showed glass‐transition temperatures (T_g) ranging from 283 to 329°C and good thermal properties evidenced by no significant weight loss up to 380°C and 10% weight loss recorded above 425°C in air. All the polyamides exhibited an amorphous nature as evidenced by wide‐angle X‐ray diffraction and demonstrated a film forming capability. Water uptake values up to 3.35% were observed at 65% relative humidity. These polymers exhibited strong UV‐vis absorption maxima at 357–369 nm in DMSO solution, and no discernible photoluminescence maxima were detected by exciting with 365 nm. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Preparation and properties of biocomposites composed of epoxidized soybean oil,tannic acid,and microfibrillated cellulose

As a new biobased epoxy resin system, epoxidized soybean oil (ESO) was cured with tannic acid (TA) under various conditions. When the curing conditions were optimized for the improvement of the thermal and mechanical properties, the most balanced properties were obtained when the system was cured at 210°C for 2 h at an epoxy/hydroxyl ratio of 1.0/1.4. The tensile strength and modulus and tan δ peak temperature measured by dynamic mechanical analysis for the ESO–TA cured under the optimized condition were 15.1 MPa, 458 MPa, and 58°C, respectively. Next, we prepared biocomposites of ESO, TA, and microfibrillated cellulose (MFC) with MFC contents from 5 to 11 wt % by mixing an ethanol solution of ESO and TA with MFC and subsequently drying and curing the composites under the optimized conditions. The ESO–TA–MFC composites showed the highest tan δ peak temperature (61°C) and tensile strength (26.3 MPa) at an MFC content of 9 wt %. The tensile modulus of the composites increased with increasing MFC content and reached 1.33 GPa at an MFC content of 11 wt %. Scanning electron microscopy observation revealed that MFC was homogeneously distributed in the matrix for the composite with an MFC content of 9 wt %, whereas some aggregated MFC was observed in the composite with 11 wt % MFC. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011