核壳型聚丙烯酸酯乳液的耐水性能研究

采用种子乳液二阶段聚合法,制备了经丙烯酸(AA)/丙烯酰胺(AM)交联、具有核壳结构的甲基丙烯酸甲酯(MMA)/丙烯酸丁酯(BA)/丙烯腈(AN)复合乳液,研究了核壳软硬单体比、AN及壳层中交联单体AM含量对乳胶膜吸水率的影响。结果表明:乳胶膜吸水率主要受壳层软硬单体比例的影响,软硬单体比值越小,乳胶膜的吸水率越低;丙烯酸/丙烯酰胺复合交联剂对乳胶膜吸水率的影响不明显;功能单体丙烯腈可明显降低乳胶膜的吸水率,乳胶膜吸水率随丙烯腈含量的增加而逐渐降低,最低达到9.40%。     

交联剂含量对核壳型聚丙烯酸酯乳液及胶膜性能的影响

以三羟甲基丙烷三甲基丙烯酸酯(TMPTMA)为交联单体,采用半连续种子乳液聚合法,以甲基丙烯酸甲酯(MMA)和丙烯酸丁酯(BA)为主要单体合成了核壳型聚丙烯酸酯乳液,研究了核层TMPTMA含量对乳液及胶膜性能的影响。结果表明,在一定范围内,随着核层TMPTMA含量的增加,乳胶粒子的平均粒径减小,凝聚率增大;胶膜的拉伸强度及断裂伸长率均增大,与水的接触角变小;在反应条件、单体种类及配比相同的情况下,核壳型丙烯酸酯乳胶膜比非核壳型乳胶膜的杨氏模量及拉伸强度明显变大。     

KH-570对硅丙核/壳乳液合成及性能影响的研究

以甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)和丙烯腈(AN)为主要原料,γ-(甲基丙烯酰氧基)丙基三甲氧基硅烷(KH-570)为改性剂,采用半连续种子乳液二阶段聚合法制备出一种核/壳结构型硅丙乳液。研究结果表明:KH-570含量对胶膜吸水率影响较小;胶膜力学性能及其保持率随KH-570含量增加而增大;当w(KH-570)=5%(相对于单体总质量而言)时,乳液及其胶膜的综合性能相对最好,其吸水率、拉伸强度和断裂伸长率分别为6.92%、13.37 MPa和43.98%,吸水48 h后拉伸强度和断裂伸长率分别为12.01 MPa和40.02%,吸水48 h后拉伸强度和断裂伸长率的保持率分别为89.83%和91.41%。     

环氧树脂与丙烯酸酯复合改性水性聚氨酯的合成研究

用环氧树脂E-44和甲基丙烯酸甲酯(MMA)复合改性水性聚氨酯(WPU),丙烯酸羟乙酯(HEA)与MMA发生共聚反应.制得以丙烯酸酯为核,聚氨酯为壳,HEA为核壳之间桥连的核壳交联型PUA复合乳液.这种复合乳液集中了聚氨酯的耐低温、柔软性好、附着力强,丙烯酸酯的耐水和耐候性好,环氧树脂的高模量、高强度、耐化学性好等许多优点.实验研究结果表明:随着环氧树脂E-44和MMA添加量增大,胶膜硬度、拉伸强度和耐水性逐渐提高,胶膜断裂伸长率和乳液的稳定性则随着降低.当环氧E-44含量为4%,MMA含量为20%～30%时综合性能较好.     

乙烯基硅烷改性丙烯酸酯乳液的合成及性能研究

采用种子乳液聚合法制备了经乙烯基三乙氧基硅烷(VTES)改性,具有核壳结构的甲基丙烯酸甲酯(MMA)/丙烯酸丁酯(BA)/丙烯腈(AN)复合耐水硅丙乳液,研究了VTES用量对乳液及乳液胶膜性能的影响。结果表明:乳胶膜吸水率受有机硅VTES的影响很小;随着VTES用量增大,乳胶膜力学性能及其保持率都升高;当VTES用量为5%时,乳液及乳液胶膜的综合性能最好。     

水性聚氨酯改性天然胶乳膜的制备及性能

采用机械法制备水性聚氨酯(WPU)/天然胶乳(NRL)的共混乳液,自然流延并在热空气中硫化制得WPU/NRL硫化胶膜,考察了不同WPU用量下共混乳液的加工性能、胶膜硫化特性和硫化胶膜的力学性能、透气性及耐溶剂性。结果表明:随着WPU用量的增加,共混乳液的黏度上升,表面张力变化较小。WPU/NRL胶膜的正硫化时间缩短,交联密度先增大后减小;硫化胶膜的断裂伸长率降低,拉伸强度和300%定伸应力先增大后减小,硬度增大,当WPU用量为7.5份时,硫化胶膜的拉伸强度达到27.84 MPa。与NRL硫化膜相比,WPU/NRL硫化胶膜的透气性有所降低,耐溶剂性能与致密性得到改善。     

形状记忆水性聚氨酯制备与性能研究

以聚己二酸-1,4-丁二酸酯二醇(PBA)和异佛尔酮二异氰酸酯(IPDI)为主要原料,三羟甲基氨基甲烷(TOAM)为交联单体,采用预聚体分散法合成了形状记忆水性聚氨酯(SMWPU)。探讨了交联单体TOAM用量对乳液和胶膜性能的影响并表征了胶膜的形状记忆性能。结果表明:随着TOAM用量的增加,乳液粘度先增大后减小,粒径先增大后趋于稳定,拉伸强度增大而断裂伸长率降低,硬段表现为非晶态,软段微区结晶度降低,TOAM质量分数为4.5%时,形状回复率可达90.15%。     

TMPTA交联改性水性丙烯酸树脂的制备及性能

以丙烯酸丁酯和甲基丙烯酸甲酯为主要单体,甲基丙烯酸缩水甘油酯和丙烯酸为功能性单体,三羟甲基丙烷三丙烯酸酯(TMPTA)为交联剂,采用乳液聚合法合成了水性丙烯酸树脂。通过测量乳液粒径和黏度,热重分析,机械性能和吸水率测试,考察了TMPTA用量对乳液及其胶膜性能的影响,并用红外光谱表征了胶膜的结构。结果表明,TMPTA的加入可提高胶膜的拉伸强度、硬度、热稳定性和耐水性。当TMPTA用量为6%时,乳液的平均粒径为78.49 nm,黏度为29.77 mPa·s。其胶膜的综合性能最好:交联度96.63%,邵氏硬度44 HA,T剥离强度0.46 kN/m,拉伸强度2.30 MPa,断裂伸长率154.2%,吸水率3.60%,失重率为50%时的分解温度为411℃。     

丙烯酸酯乳液的合成及改性研究

以丙烯酸丁酯(BA)和丙烯酸-2-乙基己酯(2-EHA)为软单体、甲基丙烯酸甲酯(MMA)为硬单体、丙烯酸(AA)为功能单体、甲基丙烯酸羟乙酯(HEMA)为交联单体和十二烷基硫酸钠(SDS)/乳化剂(OP-10)为阴/非离子型复合乳化剂,采用核/壳种子乳液聚合法制备了丙烯酸酯共聚乳液;然后在壳层聚合时寸加入HEMA,并用乙烯基有机硅进行改性,制得硅丙乳液。结果表明:当m(SDS):m(OP-10)=3:2、w(复合乳化剂)=3.4%、w(引发剂)=0.82%、w(HEMA)=3.5%、聚合温度为80℃以及聚合中期加入6.8%乙烯基硅油至壳单体中时,硅丙乳液及其胶膜的稳定性、耐水性和力学性能俱佳。     

采用磺酸型亲水单体作为扩链剂制备水性聚氨酯的研究

以聚醚二元醇(N210)和2,4-甲苯二异氰酸酯(TDI)为原料,以自制的磺酸型亲水单体1,2-二羟基-3-丙磺酸钠(DHPA)作为扩链剂,制备了磺酸型水性聚氨酯(WPU)乳液;研究了R值[即R=n(-NCO)/n(-OH)]、DHPA含量对WPU乳液及其胶膜力学性能的影响,并对产物的结构进行了红外光谱(FT-lR)表征.研究结果表明,随着R值的增大,WPU乳液粘度下降,胶膜的拉伸强度和硬度增大、断裂伸长率和吸水率下降;随着DHPA含量的增加,WPU乳液的稳定性逐渐增强、粒径变小且粒径分布变窄,WPU胶膜的拉伸强度增大、断裂伸长率则呈先增后降的趋势;当R=2.0、wDHPA)=5%时,WPU的综合性能最好.     

Fabrication and characterization of polysiloxane/polyacrylate composite latexes with balanced water vapor permeability and mechanical properties: effect of silane coupling agent

In order to improve the water vapor permeability and mechanical properties of latex films, polysiloxane/polyacrylate (PSi/PA) composite latexes were fabricated via seeded emulsion polymerization of methyl methacrylate and butyl acrylate onto PSi latex particles, and the effects of the silane coupling agent 3-methacryloyloxypropyl trimethoxysilane (MATS) on the morphologies of the latex particles and films, as well as the microphase separation degree, the water vapor permeability and the mechanical properties of the latex films were investigated. Results indicated that MATS was essential for obtaining the PSi/PA composite latex particles with PSi as core and PA as shell and made a great contribution to restrict the phase separation. The PSi/PA core/shell latex films showed similar tensile strength and elongation with pure PA film, while exhibiting promising water vapor permeability. It was found that the influences of MATS content on the water vapor permeability and mechanical properties were opposite, and on the premise of the requirements for mechanical properties, lower MATS content could provide the PSi/PA core/shell latex films with better water vapor permeability.     

Preparation and properties of polydimethylsiloxane/polyacrylate composite latex initiated by 60Co γ‐ray irradiation

In this study, polydimethylsiloxane (PDMS)/polyacrylate composite polymer latex was synthesized via polymerization of the acrylate monomer in the presence of vinyl‐containing PDMS seeded latex. The polymerization was initiated by ⁶⁰Co γ‐ray irradiation. The morphology of the PDMS/polyacrylate composite polymer latex was a core–shell structure with PDMS as the core and polyacrylate as the shell. There was an interpenetration layer between the PDMS core and the polyacrylate shell. The composition of the vinyl‐containing PDMS and the PDMS/polyacrylate composite latex were investigated with NMR and Fourier transform infrared spectroscopy, respectively. The effect of irradiation dose on the seeded emulsion polymerization conversion is discussed. Finally, the mechanical properties of latex film, such as water‐absorption ratio, tensile strength, pendulum hardness, and heat‐decomposed temperature, were tested. The results showed that the mechanical properties of the PDMS/polyacrylate film were remarkably improved when compared to the polyacrylate film. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2732–2736, 2003     

Role of acrylic acid in the synthesis of core‐shell fluorine‐containing polyacrylate latex with spherical and plum blossom‐like morphology

The core‐shell fluorine‐containing polyacrylate latex was successfully synthesized by two‐stage semicontinuous emulsion copolymerization of methyl methacrylate (MMA), butylacrylate (BA), acrylic acid (AA), and dodecafluoroheptyl methacrylate (DFMA). The fluorine‐containing polyacrylate latex was characterized by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta potential, thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC). The effects of AA content on monomer conversion, polymerization stability, particle size, corsslinking degree, carboxyl groups distributions (latex surface, aqueous phase or buried in latex), as well as mechanical properties and water absorption rate of latex film were investigated. The obtained fluorine‐containing polyacrylate latex exhibited core‐shell structure with a particle size of 120–150 nm. The introduction of AA was beneficial for the increase of monomer conversion and the polymerization stability, and had little effects on the mechanical property of latex film. However, the hydrophilicity of AA made the water resistance of latex film get bad. With the increase of AA content, the carboxyl groups preferred to distribute on aqueous phase, and the possibility of homogeneous nucleation increased and more oligomers particles were formed. Moreover, the oligomers would distribute to the latex and continued to grow up, making the latex morphology changed from spherical to plum blossom‐like. The core‐shell latex had two T_g corresponding to the rubber polyacrylate core and hard fluorine‐containing polyacrylate shell, and the latex film possessed excellent thermal stability. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42527.     

玻纤增强聚丙烯复合材料性能研究

研究了玻纤(GF)、SEBS和聚丙烯接枝马来酸酐(PP-g-MAH)用量对GF增强聚丙烯复合材料性能的影响,以及PP/GF(65/35)、PP-g-MAH/PP/GF(15/65/35)的微观形态。结果表明:随着GF用量的增加,复合材料的拉伸强度、弯曲强度和弯曲模量增加,断裂伸长率降低,冲击强度先减小后增大,PP/GF复合材料断面呈脆性断裂;在PP/GF中添加增韧剂SEBS可以提高复合材料的冲击强度,但拉伸强度、断裂伸长率、弯曲强度和弯曲模量均减小;在PP/GF中添加增容剂PP-g-MAH,可使其拉伸强度、断裂伸长率、弯曲强度、弯曲模量和冲击强度均得到提高,当PP-g-MAH/PP/GF为15/65/35时,复合材料性能优异,材料断面呈韧性断裂。     

环氧改性聚酰胺对淀粉基生物降解复合膜性能的影响

将环氧改性聚酰胺(EPA)与热塑性玉米淀粉复合后采用浇铸法制备出新型增强生物降解复合膜,研究了EPA对复合膜结晶性能、交联程度、力学性能以及生物降解性能的影响。结果表明,玉米淀粉与EPA、烷基烯酮二聚体及丙三醇复合后,结晶程度明显下降。当EPA质量分数为21 62%时,复合膜的交联度高达45 77%,且复合膜残留物中非EPA成分的质量分数也达到24 15%;复合膜的干态拉伸强度和断裂伸长率分别可以高于12 0MPa和45 0%,湿态拉伸强度和断裂伸长率则分别可以达到5 40MPa和30 0%以上。EPA的添加降低了复合膜的生物降解性能。     

单体配比对丙烯酸酯环保型塑溶胶性能的影响

采用乳液聚合方式制备丙烯酸酯乳液用于环保型塑溶胶主料：通过调整单体比例,考查了单体配比对塑溶胶性能的影响．用粒度仪对乳液粒子的粒径及其分布进行了分析,通过TEM观察了粒子的分布情况及验证了粒径大小：用DSC表征了单体配比对塑溶胶玻璃化转变温度的影响,并研究了塑溶胶的应力应变性能。结果表明,反应单体比例（以mn-BMA／mMMA计算）中甲基丙烯酸正丁酯（n=BMA）含量多时塑溶胶的断裂伸长率高,甲基丙烯酸烯甲酯（MMA）含量多时塑溶胶强度高,mn-BMA／mMMA=6／4最合适、     

纳米SiO_2/聚丙烯酸酯组装杂化乳液的合成及表征

通过乳液聚合法成功合成了纳米SiO2/聚丙烯酸酯杂化乳液。首先将纳米SiO2经过表面官能团化处理,使其表面含有活性官能团,然后经过乳液聚合使丙烯酸酯单体在纳米SiO2表面引发聚合,合成了具有核壳结构的纳米杂化乳液。采用透射电子显微镜(TEM)对乳液的微观结构进行了表征,并对胶膜进行了机械力学性能测试和表面润湿性能测试。结果表明纳米SiO2的表面官能团化处理改善了纳米粒子在乳液中的稳定性,当纳米SiO2质量分数为0 2%时,杂化乳液胶膜的拉伸强度和断裂伸长率同时达到最大值。其表面润湿性与SiO2质量分数有关,SiO2质量分数为0 5%时其杂化乳胶膜的接触角最大,耐水性最好。     

高直链玉米淀粉/PVA复合膜的制备

以高直链玉米淀粉为原料,选用乙二醇为增塑剂,硼砂为交联剂,采用流延法制备淀粉/聚乙烯醇(PVA)复合膜。研究不同直链淀粉含量、增塑剂用量、交联剂用量、等因素对复合膜性能的影响。结果表明,高直链淀粉复合膜的性能明显优于普通淀粉复合膜。当淀粉、乙二醇、硼砂用量分别为20%、30%、5%时,复合膜性能最佳。