UV-curing of hyperbranched polyurethane acrylate-polyurethane diacrylate/SiO_2 dispersion and TGA/FTIR study of cured films

UV-curable hyperbranched polyurethane acrylate-polyurethane diacrylate/SiO2 dispersion （HBPUA-PUDA/SiO2） was prepared with isophorone diisocyanate （IPDI）, hyperbranched polyester Boltorn H20 （H20）, hydroxy-ethyl acrylate （HEA）, polyethyleneglycol （PEG-200）and nano-SiO2. The UV curing kinetics of the films was investigated by FTIR. The results show that the curing speed of the films increases with the adding of nano-SiO2 and decreases with the adding of PUDA due to the slower chain movement. The thermal stability of the HBPUA-PUDA/SiO2 films was studied by using thermogravimetric analysis coupled with Fourier transform infrared spectroscopy （TGA/FTIR）. The results show that all films exhibit two degradation stages located at about 320 and 440℃ corresponding to the degradation for hard segments of urethane-acrylate and the degradation for soft segment and polyester core. In addition, the results from the analysis of TGA/FTIR also indicate that the decomposition temperature of HBPUA-PUDA/SiO2 film is 15℃ higher than that obtained for pure polymer. The degradation mechanism was proposed according to TGA/FTIR results.

Synthesis of A Novel UV-curable Oligmer 1,4-cyclohexanedimethanol Glycidyl Ether Acrylate and Study on Its UV-curing Properties

A novel UV-curable oligmer 1,4-cyclohexanedimethanol glycidyl ether acrylate（CHDMGEA） was synthesized by utilizing 1,4-cyclohexanedimethanol glycidyl ether（CHDMGE） and acrylic acid（AA） as starting materials, triphenyl phosphine as catalyst and p-hydroxyanisole as inhibitor. The optimum synthetic conditions were that the concentration of triphenyl phosphine was 0.90% of reactants by weight, the concentration of p-hydroxyanisole was 0.20% of reactants by weight, the reaction temperature was 90-100 ℃, and the molar ratio of CHDMGE to AA was 0.5：1.1. The experimental results show that CHDMGEA is a kind of good UV-curable oligmer. The impact resistance of the UV-cured films with CHDMGEA as oligmer to prepare UV-curing coating was superior to that of the UV-cured films with bisphenol A diglycidyl ether diacrylate（BPGEA） as oligmer to prepare UV-curing coating.

The application of reed-vibration mechanical spectroscopy for liquids to detect chemical reactions of an acrylic structural adhesive

There remain a number of unsolved problems about chemical reactions, and it is significant to explore new detection methods because they always offer some unique information about reactions from new points of view. For the first time, the solidification course of a modified two-component acrylic structural adhesive is measured by using reed-vibration mechanical spectroscopy for liquids （RMS-L） in this work, and results show that there are four sequential processes of mechanical spectra with time. The in-depth analyses indicate that RMS-L can detect in real-time the generation and disappearance of active free radicals, as well as the chemical cross-link processes in the adhesive. This kind of real-time detection will undoubtedly facilitate the study of the chemical reaction dynamics controlled by free radicals.

Synthesis of a Novel UV-curable Prepolymer Polypropyleneglycol Diglycidyl Ether Diacrylate

A novel UV-curable prepolymer polypropyleneglycol diglycidyl ether diacrylate （PPGGEA） was synthesized by utilizing polypropyleneglycol diglycidyl ether （PPGGE） and acrylic acid （AA） as starting materials, N, N-dimethylbenzylamine as catalyst and p-hydroxyanisole as inhibitor. The optimum synthetic conditions were in the following： the concentration of N, N-dimethylbenzylamine was 0.80 wt% of reactants, the concentration of p-hydroxyanisole was 0.3 wt% of reactants, the reaction temperature was 90-110 ~C, and the molar ratio of PPGGE to AA was 1：2.2. Meanwhile, 1-hydroxycyclohexyl phenyl ketone of a UV-cured initiator was added to the synthesized PPGGEA to prepare a kind of UV-cured coating. The mechanical properties of the UV-cured films were determined, giving 29.99 MPa of tensile strength, 834.27 MPa of the Young＇s modulus and 5.66% of elongation at tear.

Synthesis of a Novel UV-curable Prepolymer Hexanediol Diglycidyl Ether Diacrylate and Its Cured Film Tensile Property

A novel UV-curable prepolymer hexanediol diglycidyl ether diacrylate （HDGEA） was synthesized by utilizing hexanediol diglycidyl ether （HDGE） and acrylic acid （AA） as starting materials, N, N-dimethylbenzylamine as catalyst and p-hydroxyanisole as inhibitor. The optimal synthetic conditions were that the concentration of N, N-dimethylbenzylamine was 0.80 wt% of reactants, the concentration of p-hydroxyanisole was 0.3 wt% of reactants, the reaction temperature was 90-110 ℃, and the molar ratio of HDGE to AA was 1︰2.2. Meanwhile, 1-hydroxycyclohexyl phenyl ketone of a UV-curing initiator was added to the synthesized HDGEA to prepare a kind of UV-curing coating. The mechanical properties of the UV-cured films were determined, giving 31.87 MPa of tensile strength, 871.88 MPa of Young＇s modulus and 6.77% of elongation at tear.

Synthesis of a Novel UV-Curable Diluent Benzyl Glycidyl Ether Acrylate and Its Application

A novel UV-curable diluent benzyl glycidyl ether acrylate(BGEA) was synthesized by utilizing benzyl glycidyl ether(BGE) and acrylic acid(AA) as starting materials,N,N-dimethylbenzylamine as catalyst and p-hydroxyanisole as inhibitor.The optimum synthetic conditions were that the concentration of N,N-dimethylbenzylamine was 0.90% of reactants by weight,the concentration of p-hydroxyanisole was 0.20% of reactants by weight,the reaction temperature was 90-100℃,and the molar ratio of BGE to AA was 1.00:1.10.The experiment shows that BGEA is a kind of good diluent.The mechanical properties of the UV-cured films with BGEA as diluent to prepare UV-curing coating were superior to that of the UV-cured films with butyl acrylate as diluent to prepare UV-curing coating.

Synthesis of a novel UV-curable prepolymer neopentyl glycol diglycidyl ether diacrylate and its cured film tensile property

A novel UV-curable prepolymer neopentyl glycol diglycidyl ether diacrylate (NPGGEA) was synthesized by using neopentyl glycol diglycidyl ether (NPGGE) and acrylic acid (AA) as starting materials, N, N-dimethylbenzylamine as catalyst and p-hydroxyanisole as inhibitor. The optimum synthetic conditions were taken as follows: The concentration of N,N-dimethylbenzylamine, 0.80% of reactants; the concentration of p-hydroxyanisole, 0.3% of reactants; the reaction temperature, 90-110 ; the molar ratio of NPGGE to AA, 1:2.2. Meanwhile, 1-hydroxycyclohexyl phenyl ketone of a UV-cured initiator was added to the synthesized NPGGEA to prepare a kind of UV-cured coating. Mechanical properties of the UV-cured films were determined, giving 28.75 MPa of tensile strength, 923.82 MPa of Young’s modulus and 5.51% of elongation at tear.

EFFECT OF ARTIFICIAL WEATHERING AND TEMPERATURE CYCLING ON THE ADHESION STRENGTH OF WATERBORNE ACRYLATE COATING SYSTEMS USED FOR WOODEN WINDOWS

The adhesion of coatings to wood is important for their long-term performance.In this study,the adhesion strength of water-based acrylate coatings used for wooden windows after exposure to artificial weathering(AW)and temperature cycling(TC)was investigated.The analysis of the adhesion quality of coatings was performed via a pull-off test and failure characteristics.The 3-layered and 4-layered white and brown acrylate dispersions from six different producers were compared and the effect of coating thickness on adhesion strength was investigated.The adhesion strength values proved to be very variable.After AW,the adhesion strength and its variability increased for all the samples.TC had no statistically significant effect on the adhesion strength values.White coating systems were initially characterized by lower adhesion strength,but after AW and TC,they reached higher adhesion strength values than brown ones.The overall highest adhesion after AW and TC was recorded for the coatings based on alkyd-acrylate hybrid basis(Producer 3),while the lowest adhesion variability after AW was measured for one type of tested acrylate coating(Producer 4).The effect of different layering on adhesion strength was not demonstrated in this study.

Effect of Phyllanthus emblica Linn.on Candida adhesion to oral epithelium and denture acrylic

Objective:To investigate the effect of Phyllanthus emblica(P.emblica) Linn,ethanolic extract on the adhesion of Candida albicans(C.albicans) to human buccal epithelial cells(BECs) and denture acrylic surfaces.Methods:Human BECs and transparent acrylic strips were pretreated with ethanolic extract solution of P.emblica fruits at concentration ranged from 18.7 to 300 mg/mL.After washing BECs and the strips were inoculated with three strains of C.albicans (ATCC 10281 and two clinical isolates)(10~7 cells/mL).Normal saline solution(NSS) and 0.2% chlorhexidine gluconate were used as negative and positive controls,respectively.BECs were harvested on 12μm-polycarbonate filters(Millipore,USA).The membrane filters and the strips were stained with Gram stain.Adherent yeast cells on 100 randomly selected epithelial cells and 20 randomly selected fields on each strip were counted under microscope.The statistical significance was calculated by Kruskal-Wallis and Tukey tests at a significant level of P【0.05. Results:Significant lower numbers of all strains of yeasts adhering to BECs and acrylic strips were observed after exposure to 75-300 mg/mL of plant extract compared with NSS.Conclusions: The present study demonstrates that P.emblica ethanolic extract interferes with the adhesion of C. albicans to BECs and denture acrylic surfaces in vitro.

MODIFIED ULTRAVIOLET-CURABLE WATER DISPERSIBLE POLYURETHANE-ACRYLATES

Three kinds of UV-curable self-emulsified polyurethane-acrylate (PUA) prepolymer, i.e., conventional, chain extended and grafted PUAs, were prepared. The relatively small particle size of the PUA dispersions indicates that the PUA prepolymers exhibit sufficient aqueous dispersibility. The PUA prepolymers can substantially lower the interfacial tension of water. Chain-extended PUA dispersions exhibit pseudoplastic behavior and thixotropy to a greater extent than do their conventional counterpart. The chain-extended and grafted PUA photocure to higher conversion than do the conventional PU equivalent. The results of DSC measurement suggest that there exists phase mixing between the hard and the soft segment phases for the PUAs based on PEG 400 that is the comparatively short soft segment in the prepolymer. For the PUA prepolymers based on PEG having higher M-n values, chain-extending and grafting could impede the phase separation between the hard and the soft segment domains. The adhesion, impact strength and flexibility of the photocured films were tested.

Effect of Structural Units on the Adhesion of Acrylic Copolymers to Fibers for Warp Sizing

Radical copolymerization of acrylic acid(AA)with acrylamide(AM)or acrylamide/acrylonitrile(AM/AN)was initiated with ammonium persulfate as initiator to produce acrylic copolymers such as bicopolymer poly(AM-co-AA)and tercopolymer poly(AM-co-AN-co-AA)for revealing the effects of the structural units of the copolymers on the adhesion of the copolymers to polyester or cotton fibers for warp sizing.The adhesion was evaluated in terms of tensile strength and work-to-break of a roving impregnated with the copolymer solution.It was found that the adhesion strongly depended on type and amount of the units incorporated into the copolymeric chains.Whether the fiber is cotton or polyester,the adhesion of the bicopolymer poly(AM-co-AA)is greater than that of polyacrylic acid or polyacyamide.Excessively increasing the amount of AM or AA unit in poly(AM-co-AA)lowers the adhesion.To enhance the adhesion of the bicopolymer,a favorable mole ratio of AM to AA is 70/30.Based on this mole ratio,incorporation of acrylonitrile units into poly(AM-co-AA)to form tercopolymer enhances the adhesion.

SEED SEMICONTINUOUS EMULSION MULTI-COPOLYMERIZATION OF (METH) ACRYLATES WITH HIGH-SOLID CONTENT: EFFECT OF THE OPERATION CONDITIONS

The seeded semicontinuous emulsion multi-copolymerization of butyl acrylate (BA), 2-ethylhexyl acrylate (2EHA), methyl methacrylate (MMA), 2-hydroxyl propyl acrylate (HOPA) and acrylic acid (AA) was used to prepare the acrylic latexes with high-solid content. The effects of monomer emulsion feed rates (R(a)) and (R/E)(E) values, the ratio of emulsifier amount between the initial charge (R) and the addition monomer emulsion (E), on the polymerization reaction features, the viscosities, surface tensions,particle sizes and particle sizes distributions of latexes, T-g and the insoluble fractions of films, the 180 degrees peel strength, tack and holding power of pressure-sensitive adhesive (PSA) tapes, prepared from the latexes, were studied. Experimental study shows that the grafting and crosslinking fraction in the PSA tapes must be controlled within a suitable range to keep the balance of the 180 degrees peel strength, tack and holding power.

A New Liposomal-Drug-in-Adhesive Patch for Transdermal Delivery of Sodium Diclofenac

Liposomes are known to have considerable potential as drug carriers such as liposomal suspension, freeze dried and cream-based systems among many other liposomal formulations. In this study a new drug-in-adhesive patch was fabricated using liposome-based nanocarrier. Transfersomes as ultra-deformable liposomes are based on phosphatidylcholin 95% (phospholipon 90G) and phosphatidylcholin 50% (phosal 50PG) were prepared and further optimized in a final acrylic patch system for effective adhesion. The prepared liposomes were added to an acrylic adhesive to obtain a new hybrid transdermal patch termed as “lipo-drug-in-adhesive” patch system. The sodium diclofenac was selected as a model drug and the permeation of the drug across rat skin was evaluated (P > 0.05), using the lipo-drug-in-adhesive patch system with various percentages of transfersomes (4% - 8%w/w) and constant concentration of the drug (2% w/w). The peel strength and tack value of samples were also examined and quantified. The maximum flux of sodium diclofenac was observed in samples containing 8% (w/w) phosphatidylcholin 50%. The peel strength and tack value in samples containing phosphatidylcholin 50% were lower than those samples containing phosphatidylcholin 95%. It was observed that with increased amount of liposome in drug-in-adhesive patch system, the rate of skin permeation of the drug was also increased. It can be concluded that the developed lipo-drug-in-adhesive patch system enhances the drug release potential of transdermal delivering systems.

Synthesis and Performances of Poly(2-ethylhexyl acrylate-co-acrylic acid) Used for Warp Sizing

A series of poly （ 2-ethylhexyl acrylate-co-acrylic acid ） s （ P （2-EHA-co-AA） ）s with different mole contents of 2-ethylhexyl acrylate （ 2-EHA ） were synthesized through free radical copolymerization in ethanol for investigating the influences of copolymer composition upon the performance such as apparent viscosity, film behaviors, and adhesion to fibers for warp sizing. The content of 2-EHA was varied from 80 % to 40 %. The adhesion was estimated by measuring tensile strength and work-to-break of impregnated roving. The film behaviors were evaluated in terms of breaking strength, breaking elongation, work-to-break, and flex- fatigue resistance. It was observed that the viscosity, adhesion, and film behaviors of the copolymers strongly depended on the content of 2-EHA. Excessively increasing or decreasing the content of 2-EHA units incorporated into the copolymeric chains reduces the serviceability of P（2-EHA-co-AA） in warp sizing. The adhesion and film behaviors of the copolymcr reach their maximal values at mole content of 50 % simultaneously. Therefore, the copolymer used as sizing agent should be synthesized under equal mole of 2-EHA and AA in monomer formulation.

Efficacy and Safety of the Skin Adhesive EpinexusTM in Surgical Patients

This single-center, randomized, and controlled intervention study compared an acrylate skin adhesive, EpinexusTM (Mitsui Chemicals, Inc., Tokyo) with Dermabond AdvancedR (Ethicon, Inc., Somerville, New Jersey). The primary endpoint was cosmetic outcome at 52 weeks after treatment (Manchester Scar Scale), and the secondary endpoints were cosmetic outcome at 4 and 26 weeks after treatment (Manchester Scar Scale), wound closure, and usability. We evaluated 59 patients (29 cases and 30 controls). Failures and adverse events were also evaluated, and 8 adverse events (5 cases and 3 controls) were reported (epidermolysis, n = 4;contact dermatitis, n = 1;eczema, n = 1;and surgical wound dehiscence, n = 2). No difference was observed between groups in cosmetic outcome at 52 and 24 weeks;however, at 4 weeks, cases showed better cosmetic outcome compared with controls. With regard to usability, the treatment duration and application time were significantly longer with EpinexusTM, and ease of application was significantly better with Dermabond AdvancedR.

Synthesis of A Novel Photosensitive Prepolymer with Trimethylolpropane Triglycidylether and Acrylic Acid as Starting Materials

A novel photosensitive prepolymer of trimethylolpropane triglycidylether triacrylate was synthesized by utilizing trimethylolpropane triglycidylether and acrylic acid as two starting materials, triphenyl phosphine as catalyst and p-hydroxyanisole as inhibitor. The optimum synthesis conditions were that the concentration of triphenyl phosphine was 0.85wt% of reactants, the concentration of p-hydroxyanisole was 0.3wt% of reactants, and the reaction temperature was at 90-110 ℃. Benzil dimethyl ketal of a UV-cured initiator was added to the synthesized trimethylolpropane triglycidylether triacrylate to prepare a kind of UV-cured coating. The mechanical properties of the UV-cured films were determined, giving 28.43 MPa of tensile strength, 965.59MPa of (Young's) modulus and 4.10% of elongation at tear.

FPC用改性丙烯酸酯胶粘剂的固化研究

改性丙烯酸酯类胶粘剂应用于挠性印制电路板(FPC)及其基材时,其固化程度对性能有着决定性的影响。本文以自制的环氧树脂改性的丙烯酸酯类胶粘剂为例,通过动态差示扫描量热仪(DSC)从理论上分析其非等温固化的动力学行为,以研究其在室温时的储存稳定性和高温固化的工艺条件。然后通过傅里叶变换红外光谱仪(FT-IR)研究其在室温以及125~300℃温度范围内的固化反应历程,以保证该胶粘剂应用于FPC的热固性胶膜/片的固化性能或效果。研究结果表明:(1)通过非等温DSC测试,确定了改性丙烯酸酯胶粘剂的固化动力学方程,由此推算其在10~50℃的常规储存温度下的反应速率常数K值低至10^(-5) min^(-1)级别及以下,具有优异的B阶稳定性;同时在180℃及以上的K值达到10^(-1) min^(-1)级别,可以满足其高温烘烤迅速固化的使用要求。(2)由动态DSC测试得到的三种特征温度,进而推算本胶膜的理论固化温度为182℃,且在此温度下实现100%固化需时约100 min,并通过DSC测试进行了验证。(3)通过FT-IR对比验证了以上高温固化的反应历程,其在200℃处理后环氧基基本反应完全,这与以上分析的结果一致。

丙烯酸酯胶黏剂的刺激性及其防护

研究了第二代丙烯酸酯胶黏剂(SGA)对皮肤的刺激性,特别关注了其与变态反应性皮肤病的关系。实验探讨了不同材质手套对SGA的阻隔效果,发现一次性天然橡胶手套在接触胶黏剂后易发生溶胀,而加套一层一次性PE手套则能有效阻止胶黏剂的渗透和致敏成分透过。

水利工程用环氧树脂改性聚氨酯丙烯酸酯性能研究

水利工程金属结构和水工建筑物常遭受腐蚀、高速含沙水流磨蚀破坏,需对其进行便捷有效的防护。利用环氧树脂对聚氨酯丙烯酸酯(PUA)进行改性提高PUA与基体黏结性能,采用紫外光(UV)固化技术制备PUA涂层。研究了环氧树脂改性PUA的化学结构及环氧树脂用量对PUA的力学性能、热稳定性能、耐溶剂性能和抗冲磨性能的影响。结果表明,环氧树脂改性PUA的拉伸强度随着环氧树脂用量增加,呈下降趋势,当加入5%时,PUA拉伸强度为103.0 MPa,材料呈强而脆的特性。环氧树脂加入提升了PUA的拉伸剪切强度,由0.25 MPa增至1.60 MPa。同时,环氧树脂改性PUA具有良好的耐水性能、耐溶剂性能、抗冲磨性能,5%环氧树脂改性PUA抗冲磨强度为800 h/(kg·m^(2))。

3M^(TM) Acrylic Foam Tape 5363在轨道车辆按钮开关上的脱胶分析及工艺优化

随着中国轨道交通的发展,越来越多的轨交产品走出国门、走向世界,其中以地铁门系统最具特点。按钮开关作为门系统上的关键电子产品之一,有控制开、关门的作用,在国外被广泛采用到门系统上。其中设有盲文的按钮开关,因充分考虑特殊人群出行,深受国外客户的青睐。按钮开关盲文盖板粘接的可靠性就显得至关重要,要考虑列车不同的运行环境及各种外界因素,否则就会因为粘接不好,导致盲文盖板翘边或者脱落,引起客户的投诉和不满。企业不得不进行国外整改返修,耗费巨大的人力物力成本,也为公司带来巨大的质量损失。针对盲文盖板出现的粘接问题,对工艺路线进行总结优化,从源头上解决问题。