原位制备淀粉接枝聚乳酸

研究了淀粉与乳酸的原位接枝反应.结果表明,利用乳酸中所含的水先将淀粉糊化,然后在95℃下减压反应,可直接得到淀粉-聚乳酸接枝共聚物.研究发现,上述反应体系中可原位生成丙交酯.该丙交酯的开环聚合是淀粉发生接枝反应的主要原因.利用定量核磁共振等方法对接枝产物的微结构进行了详细的解析.     

氧化锌催化淀粉/乳酸接枝共聚物的制备与表征

以氧化锌为催化剂,采用原位聚合法制备了淀粉/乳酸接枝共聚物。由FT-IR、1H NMR、XRD和SEM对接枝产物进行了表征,且讨论了反应温度、淀粉与乳酸质量比、催化剂用量和反应时间对淀粉接枝率的影响,结果表明,当反应温度为95℃,淀粉与乳酸质量比为1∶5,催化剂用量为乳酸质量的1.0%,反应时间11 h时,产物的接枝率可达到14.20%。     

丙烯酰胺与玉米淀粉接枝共聚物的合成及其吸水性能研究

本文以硝酸铵为引发剂N，N-亚甲基双丙烯酰胺为交联剂，将丙烯酸胺与玉米淀粉接枝共聚合成了吸水剂。实验表明，当脱水葡萄糖单元与丙烯酰胺摩尔比为1：4，交联度为0．2％时，其吸水率最高可达18g／g，其对1％食盐水的吸收率为其吸水率的90％左右。然后，将以上吸水树脂以10％NaOH于60℃水解3h，制备了另一种吸水剂，吸水率约提高了16倍，但其吸1%食盐水的能力只有其吸水能力的10％左右。     

高锰酸钾引发丙烯腈与木薯淀粉的接枝共聚及共聚物的水解

研究了木薯淀粉经碱糊化后,以KMnO_4为引发剂,在酸性介质中与丙烯腈的接技共聚。结果表明,单体转化率高,接技效率达95％,支链分子量达30万。接技共聚物在碱溶液中的水解产物吸水能力可超过自重的2000倍。     

两性淀粉接枝共聚物在中性抄纸中的应用

为考察两性淀粉与丙烯酰胺接枝共聚及阳离子合成的具有功能化、网络化的多元变性淀粉对纸张的增强效果,采用废纸浆为原料,在中性抄纸条件下,对该多元变性淀粉的增强应用性能进行了研究。结果发现,两性淀粉与丙烯酰胺接枝共聚物(AS-g-PAM)及其阳离子化的衍生物(AS-g-CPAM)比两性淀粉具有更好的增强效果,尤其可大幅度提高纸张的环压强度。与两性淀粉比较,用量为0.5%AS-g-PAM和AS-g-CPAM可分别提高环压指数22%和45%以上,对纸张的抗张指数、耐破度等也比使用两性淀粉有不同程度的提高,同时,AS-g-CPAM在0.05%的低用量时,仍具有较好的增强效果。     

淀粉-醋酸乙酯-丙烯酸乙酯接枝共聚物

在硝酸铈铵(CAN)以及硫酸亚铁/过氧化氢两种引发体系中，进行了丙烯酸乙酯(EA)、醋酸乙烯酯(VAc)与玉米淀粉的接枝共聚。用质子核磁共振研究了接枝支链的化学组成、用X衍射研究接枝共聚物结晶结构的变化、用扫描电镜研究了材料的微观结构、并研究了共聚物的亲水性。制备了接枝淀粉、聚乙烯醇的生物降解塑料，测定了材料的力学性能以及疏水性。     

淀粉接枝丙烯酸乙酯及其增容性

研究了在挤出机中采用高温和剪切力的作用直接引发淀粉与丙烯酸乙酯的接枝共聚合反应．讨论了反应条件对接枝反应的影响，研究了接枝物在淀粉与聚乙烯共混物中的增容作用．实验结果表明，高温和剪切力可以引发淀粉与丙烯酸乙酯的接枝共聚合反应．接枝物作为增容剂，可以明显地改善淀粉与聚乙烯共混物的力学性能和流变性能．     

阳离子型接枝淀粉的合成及其絮凝性能

以玉米淀粉(St)和甲基丙烯酰氧乙基三甲基氯化铵(DMC)为原料,硝酸铈铵为引发剂,合成了阳离子型接枝淀粉St-g-PDMC,并使用IR、SEM和XRD对产物的结构进行了表征。结果表明,St-g-PDMC的最佳合成条件为m(St):m(DMC)=1:1,引发剂用量为反应物固含量的15%,反应温度60 ~oC,反应时间4 h。在此条件下合成的St-g-PDMC的氮含量为3.27%,接枝率为94.22%。以高岭土悬浊液为模拟水样测试St-g-PDMC的絮凝性能。结果表明,当模拟水样的pH=7时,St-g-PDMC的最佳用量为9 mg·L~(-1),絮凝后水样的透光率可达91.22%。     

多孔球状淀粉接枝共聚物的合成及其性质研究

报道了一种多孔球状淀粉接枝共聚物的合成。此球有很强的机械性能，良好的稳定性和较高的致孔率，平均孔径约为１９．５ｎｍ，以其为载体固定化糖化酶活力为１４６２ＩＵ／ｇ干胶，比活为２９．３１ＩＵ／ｍｇ蛋白。     

羟乙基纤维素接枝N-异丙基丙烯酰胺的研究

利用硝酸铈铵引发了羟乙基纤维素与N-异丙基丙烯酰胺的接枝反应.通过红外光谱和1H-NMR谱证明了接枝反应是成功的讨论了单体浓度、引发剂浓度、反应温度对接枝共聚反应的影响。通过差示扫描量热仪和动态激光光散射仪。研究了接枝产物的溶液性质,证明了接枝产物具有温敏性。     

Structure and properties of chlorinated polyvinyl chloride graft copolymer with higher property

In this work, maleic anhydride (MAH) was grafted onto chlorinated polyvinyl chloride (CPVC) with high chlorine content (66 wt%) via in‐situ chlorinating graft copolymerization (ISCGC) to obtain the material with improved mechanical strength, softening point, and thermal stability of the material. The structure of the graft product (CPVC‐cg‐MAH) was characterized by FTIR, ¹H NMR, GPC, and UV. CPVC‐cg‐MAH contains less vinylidene chloride (CCl₂) units and double bond than corresponding CPVC. Meanwhile, the number–average molecular weight (M_n) and weight–average molecular weight (M_w) of CPVC‐cg‐MAH are increased, but distribution of molecular weight (M_w/M_n) is decreased. Then, the tensile strength and notched impact strength of CPVC‐cg‐MAH increased by 14.5 and 34.6%, respectively. Furthermore, the results of DMA, DSC, TG, and Vicat softening point showed that the loss peak of CPVC‐cg‐MAH was higher evidently than CPVC and moved to high temperature, the glass transition temperature (T_g) of CPVC‐cg‐MAH was consistent with CPVC, initial weight loss temperature, and maximum weight loss rate temperature of CPVC‐cg‐MAH increased by 7.2°C and 6.1°C, respectively, and the Vicat softening temperature of CPVC‐cg‐MAH increased by 15°C and up to 130°C. Copyright © 2011 John Wiley & Sons, Ltd.     

The interaction of vinyl monomers and poly (ethylene terephthalate) in the presence of various initiators produces a physical mixture,not a graft copolymer

The interaction between poly(ethylene terephthalate) and four vinyl monomers, methacrylic acid, methyl methacrylate, styrene, and vinyl acetate, has been studied using hydrogen peroxide, benzoyl peroxide, azobisisobutyronitrile, and cobalt acetylacetonate as initiators. The ease of addition of the monomer to the polymer follows the solubility of the monomer in the polymer film. No chemical interaction occurs between the PET film and the monomer; rather, the monomer is homopolymerized within the film and forms a semi-interpenetrating network so that the two homopolymers cannot be separated unless the PET matrix is destroyed. © 1995 John Wiley & Sons, Inc.     

Chemical initiation of graft copolymerization of methyl methacrylate onto styrene–butadiene block copolymer

When a solution containing both styrene–butadiene block copolymer (SBS) and methyl methacrylate is treated with an initiator both homopolymerization of the methyl methacrylate and graft copolymerization of the methyl methacrylate onto the SBS occur. The amount of graft copolymerization depends upon the time and temperature of the reaction, the concentrations of all species, and the identity of the solvent and initiator. The combination of benzoyl peroxide in chloroform gives the highest graft yield and the reaction occurs by removal of an allylic hydrogen from the SBS by the initiator radical and subsequent addition of monomer units to that site; there is a significant solvent effect. Both AIBN and BPO function by the removal of an allylic hydrogen atom from SBS; BPO is able to effect this reaction relatively easily while AIBN can remove the hydrogen atom only with great difficulty and to a limited extent. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 965–974, 1997     

CAN引发S-DMDAAC-AM接枝共聚的研究

以硝酸铈铵(CAN)为引发剂,以淀粉(S)、二甲基二烯丙基氯化铵(DMDAAC)和丙烯酰胺(AM)为原料,通过反相乳液聚合,合成接枝共聚物。研究了加料顺序、引发剂浓度、单体与淀粉配比、油水体积比、乳化剂用量等因素对产品性能的影响。并用IR和1H-NMR对接枝产物进行了分析表征。     

淀粉与丙烯酰胺流变相的微波辐射接枝共聚

微波辐射淀粉接枝乙烯基类单体的共聚反应，一般都采用溶液聚合，得到的产物含水量大，产物分离困难。本文将流变相反应法用于接枝共聚反应，探讨微波辐射下玉米淀粉与丙烯酰胺流变相态接枝共聚反应。     

Surface modification of polyamide-6: graft copolymerization of vinyl monomers onto polyamide-6 and thermal analysis of the graft copolymers

Graft copolymerization of vinyl monomers onto polyamide-6 using radical initiation has been investigated. Two monomers were used: methacrylic acid and acrylic acid. The initiators selected included hydrogen peroxide, benzoyl peroxide and azobisisobutyronitrile. The extent of graft copolymerization depends on the concentrations and identity of the initiator and monomer and the time and temperature of the reaction. The graft copolymers were not soluble in solvents that will dissolve the starting material; definitive proof for the formation of the graft copolymers was obtained from infrared spectroscopy. Thermogravimetric analysis was performed on the graft copolymers and it was found that the presence of the acid invariably accelerated the degradation of the polyamide. © 1998 John Wiley & Sons, Ltd.     

淀粉接枝共聚丙烯酸-丙烯酰胺煤尘抑尘剂的合成及应用

以淀粉为亲水主链,丙烯酸和丙烯酰胺为接枝单体,利用加聚反应合成了新型煤尘抑尘剂.从保湿、凝聚和固结机理出发,测试了其水溶性、吸水保水能力、黏度,以及对煤尘的渗透性和润湿性、凝聚能力、固结能力,评价了其应用性能.结果表明,所合成的煤尘抑尘剂对煤尘具有长效抑尘作用.     

过硫酸铵-亚硫酸氢钠引发活化淀粉与丙烯酰胺反相乳液聚合动力学研究

以过硫酸铵-亚硫酸氢钠作为氧化还原引发剂,研究了经球磨活化的淀粉与丙烯酰胺在反相乳液体系中的接枝共聚反应动力学,分别考察了反应温度、引发剂浓度、淀粉浓度、单体浓度、乳化剂用量对接枝速率的影响.结果表明,在实验考察范围内的动力学关系式为:Rp∝[(NH4)2S2O4)]0.571[NaHSO3]0.571[St]0.59...     

Cation-exchange fabric prepared by electron beam-induced graft copolymerization of binary monomer mixture

Applying the electron-beam preirradiation method in air the cation - exchange fabric (CEF) containing sulfonic acid (R-SO₃H) groups was prepared by graft copolymerization of sodium styrenesulfonate with acrylic acid onto non woven polypropylene fabric. The effect of reaction conditions on the grafting yield and reaction mechanism was examined. The ion-exchange properties towards Cu(II) and Co(II) ions of the CEF were investigated depending on the form of the CEF and a pH of the solution. It was found that the synthesized CEF contains both strong acid groups (R-SO₃H) and weak acid (R-COOH) groups in almost equal proportion. The utilization of the CEF in Na₊ form allows to make the best use of its ion-exchange capacity.