不同混凝剂对马铃薯淀粉废水混凝效果的影响

用混凝剂Fe2(SO4)3、PAC、PFSS、PAFC处理马铃薯淀粉废水,研究了混凝剂的种类、投药量、废水pH值、助凝剂PAM的投加量以及沉降时间等对混凝效果的影响。结果表明,混凝沉淀法预处理马铃薯淀粉废水优选混凝条件为:pH为7,混凝剂PAFC为1 200 mg/L,助凝剂PAM为5 mg/L,沉降25 m in。在此条件下,废水的浊度、COD去除率分别达97.27%及40.55%。投药量明显减少,而沉积物产量较高,为后续生化处理提供了有利条件。     

马铃薯淀粉废水处理及资源化利用研究进展

马铃薯淀粉废水由清洗废水、淀粉提取废水、淀粉清洗废水3种工艺废水组成。根据3种工艺废水的水质特点,提出清洗废水应进行沉淀循环利用,淀粉提取废水宜先回收利用后再处理,淀粉清洗废水可采用常规处理的观点。综述了当前国内这3种工艺废水处理技术的研究现状,对各种技术的优缺点进行了分析,提出光合细菌法是一种非常有前途的处理马铃薯淀粉废水和其它高浓度有机食品工业废水的技术。     

CAN - KPS体系引发淀粉接枝共聚为絮凝剂的工艺研究

为克服引发剂铈盐较昂贵,工业应用难的缺点,实验采用CAN-KPS复合引发体系引发丙烯腈接枝改性淀粉,采用接枝率和接枝效率作为评价接枝效果的指标,详细研究了接枝工艺及其引发剂浓度、丙烯腈单体的用量和接枝温度对接枝率和接枝效率的影响,结果表明:接枝率达130%以上,接枝效率达90%以上,可较好地代替铈盐引发剂。接枝后对接枝淀粉的结构分析表明:淀粉大分子上已接枝上丙烯腈单体;接枝反应不仅发生在淀粉的无定形区也发生在结晶区,且接枝后接枝淀粉的结晶度有所提高。     

Electron‐beam processing of destructurized allylurea–starch blends: Immobilization of plasticizer by grafting

Allylurea (AU) was used as a reactive additive with poor aptitude to homopolymerization for obtaining grafted plasticized starch films with stabilized physical properties. Potato starch was mixed with AU (30–50 parts per hundred/pph) in a mixer operating at 125°C. Upon storage in well‐defined hygrothermal conditions, the resulting thermoplastic material shows strong plasticizer migration revealed by AU crystals blooming at the samples surface and exhibits strong opacity assigned to phase separation of the organic additive inside the material. Freshly prepared thermoplastic films of appropriate thickness were exposed to a 175‐kV electron beam (EB) radiation for inducing covalent grafting of AU by a free radical process. FTIR monitoring of the resulting chemical changes in thin films of AU–starch blends indicates unambiguously the transformation of AU allylic bond. High irradiation doses are required for achieving complete conversion of AU in the blend. However, no detectable AU migration was observed for intermediate AU conversion, probably as a consequence of higher plasticizer solubility in the grafted polysaccharide. Examination of the viscoelastic properties by dynamic mechanical thermal analysis shows that artificial aging by placing the films alternatively in high and low relative humidity (RH) atmosphere does not significantly alter the thermomechanical spectrum of the material reconditioned in a cell at 58% RH. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 409–417, 1999     

Synthesis and electrorheology of potato starch phosphate

Potato starch phosphate (PSP) particles were synthesized via an esterification process of potato starch with a mixture of various concentrations of phosphoric acid and urea. The electrorheological (ER) characteristics of the synthesized PSP particles, suspended in a silicone oil, were examined. The PSP granule‐based ER fluid exhibited typical ER behavior, possessing a nonvanishing yield stress under an applied electric field. Enhanced polarization and higher yield stresses were observed as the content of phosphate groups in the starch increases. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1770–1773, 2004     

氧化还原引发下的淀粉、丙烯酸反相乳液聚合

以环己烷为连续相,Span20为乳化剂,采用氧化还原引发体系,通过反相乳液聚合技术,合成淀粉、丙烯酸接枝共聚物。并用红外光谱对共聚物进行了表征。研究结果表明:采用氧化还原引发剂可使聚合反应低温快速进行,在过硫酸钾为3.1mmol/L,亚硫酸氢钠为3.1mmol/L,单体丙烯酸浓度为2.6mol/L,反应温度为30℃,反应时间为3h,乳化剂浓度为5%时,单体转化率为92.6%、淀粉接枝率为43.2%、淀粉接枝效率56.4%。     

冷法H_2O_2氧化制备马铃薯淀粉粘合剂及改性研究

在室温下,以马铃薯淀粉为原料,双氧水为氧化剂,制备出了马铃薯淀粉粘合剂.探讨了氧化剂用量、催化剂用量、糊化剂用量、氧化时间、糊化时间、粉水比、络合剂用量对粘合剂性能的影响,以粘度和初粘力为评价指标,通过L18(37)正交试验确定制备淀粉粘合剂的最佳条件为:m(水)∶m(马铃薯淀粉)=5∶1,双氧水1.3 mL,硫酸亚铁0.2 g,NaOH为3.0 g,氧化时间90 min,糊化时间30 min,硼砂0.3 g.并以添加聚乙烯醇进行接枝改性,提高其干燥时间和初粘力,实验得到添加量为5%时效果最好.     

聚丁二烯橡胶接枝苯乙烯本体自由基聚合机理

采用傅里叶变换红外光谱法和碘值法分析了在热引发和化学引发方式下,低顺式和高顺式聚丁二烯橡胶接枝苯乙烯聚合物的双键结构和含量,确定了橡胶接枝苯乙烯本体自由基聚合机理。结果表明,热引发时,接枝机理主要是自由基夺取橡胶链上α氢原子;而化学引发时,同时存在自由基与橡胶双键加成的机理。橡胶的结构不同导致接枝点的位置差异,在低顺式聚丁二烯橡胶体系中,自由基以夺取反式-1,4-结构和1,2-乙烯基结构为主,而在高顺式聚丁二烯橡胶体系中。自由基以夺取顺式-1,4-结构为主。     

热带假丝酵母菌处理马铃薯淀粉废水工艺优化

利用微生物发酵技术,通过正交试验研究了温度、pH值、发酵时间、接种量等因素对热带假丝酵母茵处理马铃薯淀粉废水的影响。结果表明,在温度为28℃、pH值为5．5、发酵时间为28h、接种量为10％的条件下,废水处理效果和热带假丝酵母茵生长情况最佳,且经处理后废水CODCr、色度去除率分别可达到76．0％、73．5％、77．1％．同时可获得9．53g／L的单细胞蛋白。     

UASB—SBBR—混凝—气浮工艺处理马铃薯淀粉废水

采用UASB—SBBR—混凝—气浮工艺处理沈阳市某淀粉厂马铃薯淀粉废水,介绍了厌氧和好氧反应器的启动过程,分析了各反应器的运行效果。运行结果表明:当进水COD﹑BOD5﹑SS﹑NH3-N平均质量浓度分别为13 400、6 500﹑2 000﹑160 mg/L时,相应的出水质量浓度分别为38﹑18﹑24﹑13 mg/L,达到了《污水综合排放标准》(GB8978—1996)中的一级排放标准。该工艺运行成本为0.63元/m3,适于处理马铃薯淀粉废水。     

Controlled grafting of poly(vinyl acetate) onto starch via RAFT polymerization

A structure‐exact starch‐based xanthate agent was prepared and used as chain transfer agent to mediate RAFT polymerization of vinyl acetate, which offered a convenient way to well control the structure and composition of starch‐g‐poly(vinyl acetate). The structures of the intermediate and the polymer were verified with FTIR and ¹H‐NMR. Gel permeation chromatography measurement results indicated that the polymerization was performed as expected. It was found that the relationship between number average molecular weight and monomer conversion was linear. The polydispersity index of grafted side‐chain ranged from 1.19 to 1.53 and most of them were around 1.2. There was one more degradation stage appeared on the thermogravimetric analysis profile of starch‐g‐poly(vinyl acetate) than that of starch. TEM observation exhibited that the product was able to self‐assemble into micelles in aqueous solution, which suggested the copolymer was amphiphilic. Both the thermal and amphiphilic properties demonstrated the starch‐g‐poly(vinyl acetate) was successfully synthesized as well. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

聚丙烯纤维接枝苯乙烯的研究

采用化学接枝法以苯乙烯(St)为接枝单体、过氧化苯甲酰(BPO)为引发剂,1,2-二乙烯苯(DVB)为交联剂、甲醇和正辛醇为溶剂,对聚丙烯(PP)纤维进行接枝改性。研究了原料配比和反应条件对其接枝的影响。结果表明,PP纤维上接枝St,适宜的原料配比和操作条件为:St质量与PP体积比(St/PP)为4,BPO质量与St体积比(BPO/St)为0.025,DVB与St体积比(DVB/St)为0.025,溶剂与St体积比为5,浸渍24～30h,在85℃恒温水浴中反应6～8h。在较佳条件下可得到导入率为110%-160%的接枝纤维。     

淀粉接枝丙烯腈制备絮凝剂的工艺优化及应用研究

研究了淀粉接枝丙烯腈的各种因素对接枝率和接枝效率的影响。结果表明,接枝改性淀粉絮凝剂的最佳工艺条件:可溶性淀粉与丙烯腈的质量比为1∶3,硝酸铈铵的浓度为6 mg/L,接枝温度为35℃,接枝时间为2 h。在此条件下,接枝率可达172%,接枝效率92%。所制得高分子絮凝剂较无机絮凝剂对较高浓度的有机废水有较好的浊度、COD去除率及沉降速度。     

IC反应器处理马铃薯淀粉生产废水的试验研究

试验采用超滤-IC反应器-MBR工艺处理马铃薯淀粉生产废水,重点研究了IC反应器处理马铃薯淀粉废水的工艺参数。结果表明,在常温下,当进水COD的质量浓度为6000～9000mg/L、HRT为5h、容积负荷为23.62kg[COD]/(m3·d)时,IC反应器对COD的去除率为91.43%。采用该工艺处理马铃薯淀粉生产废水完全可以达到废水回用的目的。     

紫甘薯红色素及淀粉一体化提取方法研究

探讨了紫甘薯红色素及紫甘薯淀粉的一体化提取工艺,并由正交实验最终确定最优提取条件是:料液比1:3、提取时间90分钟、粉碎粒度60目、磷酸添加量2%。按照以上各因素最佳条件,得到色素提取率96.65%,淀粉提取率95.80%。     

Preparation and characterization of grafting styrene onto LLDPE by cyclohexane compatibilization in suspension polymerization

A novel method of grafting styrene onto linear low‐density polyethylene (LLDPE) by suspension polymerization was systematically evaluated. Cyclohexane as a compatibilizer was introduced to swell and activate the surface of LLDPE molecular chain for amplifying the contact point of styrene monomer with LLDPE. A series of copolymer of grafting polystyrene (PS) onto LLDPE, known as LLDPE‐g‐PS, were prepared with different ratios of cyclohexane/styrene monomer and various LLDPE dosages. FTIR and ¹H NMR techniques both confirmed successful PS grafting onto the LLDPE chains. In addition, SEM images of LLDPE‐g‐PS particles showed that the cross‐section morphology becomes smooth and dense with suitable cyclohexane dosages, indicating a better compatibility between LLDPE and PS. The highest grafting efficiency was 28.4% at 10 mL/g cyclohexane and styrene monomer when 8% LLDPE was added. In these conditions, the LLDPE‐g‐PS elongation at break increased by about 30 times compared with PS. Moreover, thermal gravimetric analysis (TGA) demonstrated that LLDPE‐g‐PS possesses much higher thermal stability than pure PS. Therefore, the optimal amount of cyclohexane as compatibilizer could increase the grafting efficiency and improve the toughness of PS. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41671.     

淀粉醋酸酯与醋酸乙烯接枝共聚制备白乳胶

提出了用淀粉醋酸酯与醋酸乙烯接枝共聚制备白乳胶的新工艺。结果表明制得的白乳胶与单独用PVA作为保护胶体制得的白乳胶相比,粘度和耐水性得到改善,粘接强度均能达到使用标准。作为一种新型胶粘剂,其与环境相容性好,前景广阔。     

苯乙烯对马来酸酐熔融接枝聚丙烯的影响

用双螺杆挤出机分别制备了马来酸酐(MAH)和MAH-苯乙烯(St)共单体接枝共聚聚丙烯(PP)。红外光谱分析表明:MAH单体被接枝到PP大分子链上;引入St后,产物熔体流动速率从16.42 g/10min降为0.60 g/10 min;吸光度比从0.021升高到0.778,但St含量过高时,PP基体发生交联,影响接枝共聚物的加工性能。探讨了共单体St的作用机理以及交联机理。     

高浓度马铃薯淀粉废水处理工艺研究现状及发展

分析了高浓度马铃薯淀粉废水的水质特性及污染因子,介绍了目前国内外对高浓度马铃薯淀粉废水的传统处理工艺及可行性分析。通过对北方气候和马铃薯淀粉生产特点的分析,提出适合此特点的膜酵母反应器处理淀粉废水新工艺。结果表明,膜酵母反应器处理工艺适合北方马铃薯淀粉废水的高效处理。     

淀粉的羧甲基化研究

研究了不同原料配比 (淀粉、CH2 ClCOOH及NaOH的用量 )、反应介质以及反应时间等对淀粉羧甲基化反应的影响。结果表明 ,在其它条件不变时 ,( 1)当NaOH用量不大时 ,随着NaOH用量的增加 ,取代度 (DS)和CH2 ClCOOH的反应效率(RE)亦增加 ,当NaOH与CH2 ClCOOH的摩尔比为 2 .5∶1时 ,达到最大值 ,其后随着NaOH的增加 ,DS和RE急剧下降 ;( 2 )随着CH2 ClCOOH用量的增加 ,DS和RE增加 ,其中DS在CH2 ClCOOH与淀粉中葡萄糖基的摩尔比增大到 1∶1时达到最大值 ,而RE在CH2 ClCOOH与淀粉中葡萄糖基的摩尔比为 0 .75∶1时达到最高 ;异丙醇作为反应介质优于乙醇 ;在本实验的时间范围内 ,DS随着反应时间的增长而增大