降解淀粉/DMDAAC-AM接枝共聚物复鞣剂的合成及应用

酶降解淀粉与二甲基二烯丙基氯化铵(DMDAAC)和丙烯酰胺(AM)在引发剂(NH4)2S2O8(APS)作用下进行了接枝共聚合反应,制得阳离子型淀粉复鞣剂。第一步酶降解条件为m(蒸馏水)∶m(淀粉)∶m(α 淀粉酶)=180∶20∶0 2,在60℃降解1h。第二步接枝聚合反应条件为m(DMDAAC)∶m(AM)∶m(APS)=40∶20∶1 5,在75℃保温反应2h。接枝共聚物的接枝率及接枝效率分别为150%和78%,单体转化率及阳离子度分别为98 5%和37%,复鞣革对于染料及加脂剂的吸收率分别为97 3%和96 2%,用红外光谱(FTIR)对复鞣剂的结构进行了表征。     

氧化-接枝双重改性淀粉胶粘剂的制备与性能研究

以玉米淀粉为原料、过硫酸铵(APS)为氧化剂、APS-亚硫酸氢钠为引发剂、苯乙烯(St)和丙烯酸丁酯(BA)为接枝共聚单体,制得氧化-接枝双重改性淀粉胶粘剂。采用单因素试验法和正交试验法优选出制备改性淀粉胶粘剂的最佳工艺条件。结果表明:当w(APS)=0.6%、w(总单体)=20%、w(引发剂)=0.6%、反应时间为2.0 h和反应温度为65℃时,改性淀粉胶粘剂的综合性能良好,其耐水时间为200 h、吸水率为60%和黏度为850 mPa.s。     

氧化/交联双重改性淀粉胶粘剂的制备

以玉米淀粉为原料、过硫酸铵(APS)为氧化剂和三聚氰胺为交联剂,采用氧化/交联双重改性法制备淀粉胶粘剂。研究了反应时间、反应温度、氧化剂和交联剂用量等因素对改性淀粉胶粘剂耐水性和流动性能的影响。结果表明:当反应时间为2.5 h、反应温度为65℃、w(APS)=4.0%、w(甲醛)=1.00%和w(三聚氰胺)=2.5%时,改性淀粉胶粘剂的耐水性(耐水时间96 h)和流动性能(黏度750 mPa·s)均较好。     

光固化丙烯酸酯改性氯化聚丙烯的制备及性能研究

为得到光固化丙烯酸酯改性氯化聚丙烯(CPP),首先采用溶液聚合方法,用甲基丙烯酸羟乙酯(HEMA)对CPP进行功能化接枝改性,研究了HEMA含量、反应温度、引发剂含量对接枝率的影响,确定合成丙烯酸酯改性CPP最佳工艺条件为m(CPP)∶m(HEMA)=8.5∶1.5,反应温度100℃,引发剂占CPP及HEMA总质量的3%,接枝率达到6.69%。利用甲基丙烯酰氯对在接枝基础上得到的丙烯酸酯改性CPP进行光固化改性,研究了不同接枝率的丙烯酸酯改性CPP光固化改性前后,以及光固化改性产物光固化前后对表面张力和附着力的影响。结果表明:光固化改性前后,涂层表面张力均能达到40.0 m N/m以上,附着力良好;光固化改性产物光固化后表面性能仍然保持良好,附着力得到提高。     

HRP催化降解淀粉与HPA-CAE接枝共聚物的制备及性能

用丙烯酸羟丙酯与柠檬酸发生酯化反应合成丙烯酸羟丙酯柠檬酸酯(HPA-CAE),在辣根过氧化酶(HRP)/H2O2/乙酰丙酮(ACAC)体系引发下,HPA-CAE与降解淀粉发生接枝共聚反应。研究了HRP、H2O2、ACAC和HPA-CAE用量对共聚物接枝效率(GE)和接枝率(GP)的影响,结果表明,50 g酶降解淀粉(质量分数15%)与13.9 gHPA-CAE在HRP(6.4 mg)/H2O2(4.7 mL)/ACAC(1.2 g)催化下发生共聚反应为最适反应条件。用FTIR和NMR表征了接枝共聚物的结构。应用结果表明,该共聚物复鞣革手感柔软、粒面平细和厚度均匀。     

氧化淀粉交联改性PVA胶粘剂的制备和性能研究

以聚乙烯醇(PVA)和红薯淀粉为原料、硼砂为交联剂、双氧水(H2O2)和过硫酸铵(APS)为氧化剂,采用氧化交联法制备了环保、耐水和高强的氧化淀粉交联改性PVA胶粘剂。研究结果表明:淀粉和PVA之间发生了氧化反应,并形成了交联结构;当w(淀粉)=40%、w(H2O2)=3%、w(APS)=0.45%和w(硼砂)=2.0%(均相对于PVA质量而言)时,改性胶粘剂的综合性能相对最好,其胶接强度、耐水性分别为0.88 MPa、95 h,并且其流动性好、无霉变现象。     

酸解氧化淀粉胶粘剂的制备及性能研究

以蜡质玉米淀粉为主要原料、聚乙烯醇(PVA)为保护胶体,在反应过程中加入酸解催化剂[盐酸(HCl)]、氧化剂和引发剂[过硫酸铵(APS)],制得酸解氧化淀粉;然后将其与醋酸乙烯酯(VAc)、丙烯酸乙酯(EA)接枝共聚后,制得新型环保复合淀粉胶粘剂。研究结果表明:采用单因素试验法优选出接枝反应的最佳工艺条件是HCl浓度为2.0 mol/L、V(VAc)=40 mL、V(VAc)∶V(EA)=3∶1、接枝反应温度为70℃、w(淀粉乳液)=20%、w(APS)=1.2%和w(PVA)=40%(均相对于淀粉干基质量而言),此时酸解氧化淀粉胶粘剂在外观、流动性、木材污染性和粘接强度等方面均优于双醛淀粉胶粘剂和PVAc(聚醋酸乙烯酯)白乳胶。     

改性淀粉木材胶粘剂的制备及性能研究

以玉米淀粉为接枝骨架、聚乙烯醇(PVA)为保护胶体、过硫酸铵(APS)为引发剂、乙酸乙烯酯(VAc)和丙烯酸丁酯(BA)为接枝单体,采用接枝共聚法制备了改性淀粉木材胶粘剂。研究结果表明:当w(淀粉)=20%(相对于胶粘剂质量而言)、m(BA)∶m(VAc)=3∶1、m(引发剂)=0.32 g、V(氧化剂)=0.8 m L和m(PVA)=3.5 g时,改性淀粉木材胶粘剂的综合性能相对较好,其各项性能均达到HG/T 2727—2010标准中的指标要求。     

Poly(MAA-AN-DM)两性聚合物复鞣剂的制备及性能

以甲基丙烯酸(MAA)、丙烯腈(AN)和甲基丙烯酸二甲基氨基乙酯(DM)为原料,过硫酸铵(APS)为引发剂,水为反应介质,经自由基共聚合制备了Poly(MAA-AN-DM)两性聚合物复鞣剂,并将其用于皮革的复鞣。用红外光谱、核磁共振氢谱、凝胶渗透色谱、胶体电荷滴定等对聚合产物的结构和性能进行了表征。用多功能材料实验机和色度计考察了聚合物组成对复鞣革性能的影响。较佳合成条件为:聚合温度80℃,单体量比n(MAA)∶n(AN)∶n(DM)=0.9∶0.3∶0.3,引发剂w(APS)=1.5%,w(单体)=30%,反应时间5.0 h。胶体电荷滴定测出共聚物的等电点为4.36,凝胶渗透色谱分析出共聚物的数均相对分子质量为84 688,分散系数为2.07。用w〔Poly(MAA-AN-DM)〕=2%的聚合物对猪蓝湿革进行复鞣,可使蓝湿革收缩温度提高5.5℃,抗张强度增加76.5%,增厚13.2%,革身饱满、无败色现象。     

木薯双醛淀粉制备木材用胶粘剂的研究

以木薯淀粉为原料、高碘酸钠为氧化剂,在一定条件下制得双醛淀粉(DAS);然后以过硫酸铵(APS)为引发剂、聚乙烯醇(PVA)为保护胶体和醋酸乙烯酯(VAc)为DAS的接枝单体,再配合其他助剂制得双醛接枝淀粉基木材用胶粘剂。结果表明:当w(DAS中醛基)=20%、m(DAS)∶m(VAc)=1∶2.5、w(PVA)=75%、VAc为25 mL、接枝反应温度为65℃和反应时间为3 h时,胶粘剂的干、湿强度分别为3.0、2.4 MPa。     

胶原蛋白改性丙烯酸类复鞣剂的制备

该文以过硫酸铵为引发剂,以马来酸酐和丙烯酸为主要原料,通过水溶液共聚合成共聚产物,用胶原蛋白对共聚物进行接枝改性,合成了胶原蛋白改性聚丙烯酸类复鞣剂。讨论了单体质量比、反应温度、时间等条件对产品性能的影响,最佳反应条件为:m(过硫酸铵)∶m(马来酸酐)∶m(丙烯酸)∶m(胶原蛋白)=0.25∶2∶3∶0.5,共聚反应温度80℃,共聚反应时间1 h,加入胶原蛋白后在60℃继续反应3 h。对该复鞣剂进行了复鞣应用实验,讨论了该复鞣剂对皮革湿热稳定性和透水气性能的影响。结果表明,经该复鞣剂复鞣过的皮革与经商业化复鞣剂TGR复鞣过的皮革相比,表现出更好的粒面性能、丰满度、弹性及填充性能,可使皮革的收缩温度提高6℃,使皮革的透水气性能提高20%以上。     

Synthesis and application of methyl methacrylate/butyl acrylate copolymer nanoemulsions as efficient retanning and lubricating agents for chrome‐tanned leather

Two different nano‐emulsions based on methyl methacrylate/butyl acrylate copolymers have been synthesized to be used as retanning and lubricating agents for chrome‐tanned leather. The main difference and characteristics of the two prepared copolymers were studied. The nano particle size of the two copolymers was confirmed using transmission electron microscope (TEM). The influence of the prepared copolymers on chrome‐tanned leather as retanning agents was investigated. The properties of the retanned leather, namely, physicomechanical properties as tensile strength, elongation at break and water absorption, were measured. Thermal gravimetric analysis (TGA) technique was used to examine the thermal stability of the retanned leather. Also, the texture of the grain surface and fibers were inspected using scanning electron microscope (SEM). The retanned leather showed an improvement in its physicomechanical properties, as well as enhancement of its thermal stability as compared with the chrome‐tanned leather. Furthermore, the retanned leather has uniform dyestuff, softness, and firmness of grain. All these promising results provide evidence to the applicability of the prepared copolymer emulsions as efficient retanning and lubricating agents for chrome‐tanned leather. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

聚乙二醇支链型丙烯酸树脂复鞣剂的制备及应用性能

用聚乙二醇(PEG400~800)与丙烯酸(AA)进行酯化反应,所得产物聚乙二醇丙烯酸酯(PEGAA)再与AA及甲基丙烯磺酸钠(SMAS)进行共聚反应,制备了聚乙二醇支链型丙烯酸树脂复鞣剂。考察了影响酯化反应及共聚反应的因素,确定酯化反应的条件为:n(PEG)∶n(AA)=1∶1,反应温度110℃,反应时间3 h,酯化率为98%;共聚反应的条件为:n(PEGAA)∶n(AA)∶n(SMAS)=1∶1∶0.2,w(过硫酸铵)=2%,反应温度90℃,反应时间1 h。PEG800支链型丙烯酸树脂的应用效果最好。用FTIR及GPC分别对复鞣剂的结构和相对分子质量进行了表征,最好的复鞣剂质均相对分子质量为26 510,分布系数为6.21。应用结果表明,复鞣革具有丰满、柔软、弹性好、发泡感强、无败色现象等优点。     

天然橡胶接枝甲基丙烯酸羟乙酯的合成与表征

以甲基丙烯酸羟乙酯(HEMA)为接枝单体,过氧化二苯甲酰(BPO)为引发剂,合成了天然橡胶(NR)接枝聚甲基丙烯酸羟乙酯(NR-g-HEMA)。研究了BPO和HEMA用量、反应温度、反应时间以及NR塑炼时间对单体转化率、接枝率和接枝效率的影响,并采用红外光谱对接枝产物进行了表征。结果表明:当BPO用量为3%,HEMA用量为30%,反应温度为80℃,反应时间和NR塑炼时间分别为4h和30min时,NR-g-HEMA的接枝率达16%。     

Synthesis and Characterization of Starch-Poly(vinyl Acetate) Graft Copolymers and their Saponified Form

A redox initiation system based on potassium persulfate/acetone sodium bisulphite (KPS/ASBS) was developed to initiate the graft copolymerization of vinyl acetate (VAc) monomer onto corn starch in aqueous solution. The grafting reaction was studied with respect to grafting yield (GY), grafting efficiency (GE) and total conversion (TC) and results obtained were compared with those a well-established redox initiation system namely potassium persulfate/sodium bisulphite (KPS/SBS). The effect of reaction variables such as redox initiator concentration, liquor ratio, reaction time and temperature as well as VAc concentration were investigated. The GY, GE and TC increased significantly with increase of the redox initiation concentration up to 8/16 mmol/l irrespective of the initiation system used. Moreover, optimal grafting was obtained at 60 ^○C for KPS/ASBS redox system and 70 ^○C for KPS/SBS redox system. Saponification of poly (vinyl acetate)-starch graft copolymers were effected using NaOH in three different bath media (n-hexane, acetone or methanol) to convert starch-g-poly(vinyl acetate) to starch-g-poly(vinyl alcohol). Higher extent of solubility in hot water of the saponified form was achieved by using a bath containing n-hexane/sodium hydroxide; however, increasing the graft yield higher than 26.3% decreases the solubility. The structures and thermal stability of starch, grafted starch copolymer and saponified grafted starch copolymer were characterized by infrared spectroscopy and thermogravimetric analysis. Moreover, the rheological behavior as well as sizing performance of the saponified grafted starch copolymers were evaluated and compared with the native starch and commercial polyvinyl alcohol.     

固相法淀粉接枝甲基丙烯酸甲酯共聚物的制备与表征

以过硫酸铵为引发剂,在少量水存在下,研究了玉米淀粉（CS）与甲基丙烯酸甲酯（MMA）接枝共聚的反应规律。考察了含水量、反应时间与温度、MMA单体和引发剂用量等因素对接枝共聚反应的影响。实验结果表明,体系含水质量百分数为40％左右、MMA用量为CS质量的15％、过硫酸铵用量为CS质量的8％、反应温度在80℃、反应时间为0．5h左右,可得到接枝率和接枝效率均较高的接枝共聚物。通过红外光谱（FTIR）、热重分析法（TGA）以及X射线衍射法（XRD）对合成的接枝共聚物进行了表征。     

Study on antithrombosis dialytic membrane prepared by preirradiation grafting

A new antithrombosis dialytic membrane with a hydrophilic–hydrophobic microphase structure was prepared by preirradiation grafting of β‐hydroxyethyl methacrylate (HEMA) and styrene (St) onto ethylene–vinyl acetate (EVA). The influence of some effects, such as preirradiation dose, dose rate, grafting reaction temperature, reaction time, and monomer component, on the degree of grafting was determined, and the properties of the grafted films were investigated. Compared with the conventional EVA‐grafted hydrophilic monomer, the EVA films grafted with HEMA and St have superior antithrombogenicity; the antithrombogenicity and permeability of EVA‐g‐(HEMA‐co‐St) were 30 and 20 times higher than those of the ungrafted films, respectively, when the volume ratio (HEMA versus St) was about 7:3. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1321–1327, 2000