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1.
    
Modification of polypropylene (PP) has been successfully carried out by graft copolymerization of gelatin, by chemical method using benzoyl peroxide (BPO) as radical initiator. PP was preirradiated by gamma rays at a constant dose rate of 3.40 kGy/h before grafting to introduce hydroperoxide groups. Optimum conditions pertaining to maximum percentage of grafting were evaluated as a function of different reaction parameters. Maximum percentage of grafting of gelatin (115%) was obtained at BPO concentration = 4.132 × 10?2 mol/L in 120 min at 70°C using 30 mL of water. Characterization of PP‐g‐gelatin was carried out through FTIR, thermogravimetric analysis, and scanning electron microscopy. Swelling studies were carried out in pure, binary, ternary, and quaternary solvent systems comprising distilled water, ethanol, dimethylsulphoxide (DMSO), and N,N‐dimethylformamide (DMF) in different ratios. Maximum swelling of PP‐g‐gelatin (both composite and true graft) was observed in pure solvents that is, DMSO followed by DMF, ethanol, and water and was higher than that observed in the mixed solvent system. Water retention studies of unmodified PP, that is, pristine PP and PP‐g‐gelatin (both composite and true graft) were investigated at different time periods, temperatures and pH. Maximum % water retention for PP‐g‐gelatin (composite; 170%) was observed in 8 h at 50°C in neutral medium (pH = 7). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

2.
氯化等规聚丙烯的合成与表征   总被引:3,自引:0,他引:3  
采用溶液氯化方法,对用固相接枝得到的等规聚丙烯接枝马来酸酐共聚物进行氯化反应,制得氯含量为30% ̄50%(质量分数)的氯化等规聚丙烯(MCPP),用FT-IR,X-衍射,DSC和^13C NMR表征了产物的结构,MCPP树脂可广泛用于印刷油墨和涂料等。  相似文献   

3.
    
N‐vinyl pyrrolidone (NVP) was grafted onto a polypropylene copolymer (PP) in melt in a Brabender Plasticorder and single screw extruder. The effect of variation of dicumyl peroxide (DCP) and lupersol (LUP) concentrations alone and with 20 wt % NVP concentration in the Brabender Plasticorder on Melt Flow Index (MFI) and final torque values was studied. Variation of NVP concentration (1–10 wt %) at a fixed DCP concentration on percent grafting (G) and MFI was also studied in the single screw extruder. The graft copolymers (PP‐g‐NVP) obtained by reaction of PP with NVP were soxhlet extracted with isopropanol to remove homopolymer, dried, and finally characterized by Fourier transform infrared (FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The PP‐g‐NVP (0–30 wt %) was used as an additive with PP, extruded in the single screw extruder, molded, and the mechanical properties and paint adhesion was measured. MFI values increased and torque values decreased with an increase in initiator concentration, indicating the dominance of the peroxide‐initiated scission reaction over grafting. DCP gave higher grafting compared to LUP. When NVP concentration was increased, MFI values increased initially due to more scission, and then decreased, indicating more graft copolymer formation. Mechanical properties increased by incorporation of PP‐g‐NVP as an additive than PP‐g‐NVP alone. Paint adhesion increased by the presence of PP‐g‐NVP as additive especially with polyurethane primer. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2173–2180, 2003  相似文献   

4.
综述了国内外聚丙烯(PP)功能化的方法,主要包括丙烯与极性单体直接共聚法、中介物功能化法、接枝改性法等,重点讨论了后两种功能化方法。通过化学反应在PP分子结构中引入极性基团是达到PP功能化的根本途径。  相似文献   

5.
香烟滤材聚丙烯化学接枝共聚条件的研究   总被引:1,自引:0,他引:1  
用自由基化学接枝共聚的方法制作聚丙烯香烟滤材,以提高其表面能,增加自粘性。本试验对聚丙烯接枝共聚反应条件进行了研究,运用正交法、方差分析法找出了最佳聚合条件(如活性单体的种类、单体浓度、引发剂种类及浓度、反应时间)等。  相似文献   

6.
等规聚丙烯-丙烯酸接枝共聚   总被引:2,自引:0,他引:2  
详细研究了等规聚丙烯细粒子在丙烯酸水溶液中,以过氧化苯甲酰为引发剂的液-固相接枝共聚反应和十氢化萘乙醇溶液对等规聚丙烯的膨化预处理作用,检测了等规聚丙烯-聚丙烯酸的某些性质,发现随接枝率提高,其吸湿性和碱性染料染色性均提高,熔点略有降低,但熔体流动性下降,按本研究获得的最佳膨化预处理条件和最佳接枝共聚反应条件,接枝产物等规聚丙烯-聚丙烯酸的接枝率可超过13%。  相似文献   

7.
以丙烯酸酯单体作为接枝共聚单体,合成了无芳烃低VOC的CPP(氯化聚丙烯)乳液。以接枝率和耐水性作为衡量指标,采用单因素试验法优选出制备CPP乳液的最佳工艺条件。结果表明:当反应温度为95℃、反应时间为3.5 h、w(总引发剂)=1.0%(其中10%引发剂在滴加单体以前加入,并且间隔时间为10 min)、w(丙烯酸酯单体)=30%和w(丙烯酸)=5%时,相应CPP乳液的综合性能相对较好,并且其对聚丙烯(PP)基材的附着力相对最好。  相似文献   

8.
以过硫酸钾为引发剂,通过糊化淀粉接枝丙烯酰胺制备了高吸水树脂.考察了淀粉的物理状态、交联剂的用量、引发剂的浓度、共聚合温度等对产品吸水率的影响.确定接枝反应最佳工艺条件为:交联剂质量分数0.0016%、引发剂浓度6 mmol·L-1、共聚合温度60℃.  相似文献   

9.
固相接枝共聚法制备PP—g—PS   总被引:4,自引:0,他引:4  
用固相接枝共聚方法制备了聚丙烯接枝苯乙烯(PP-g-PS),详细地考察了聚丙烯与引发剂的品种、反应温度、苯乙烯及引发剂的浓度等因素对接枝率和接枝效率的影响。研究结果表明:PP-g-PS具有较高的接技率,应用于聚丙烯/聚苯乙烯(PP/PS)共混物中,能降低分散相PS的粒径,提高PP/PS的相容性。  相似文献   

10.
聚丙烯的改性   总被引:10,自引:3,他引:10  
介绍了目前广泛采用的聚丙烯改性研究方法,包括共聚,接枝,交联,填充,增强及共混改性,并重点讨论了纳米粒子改性PP的新技术,结果认为纳米PP复合材料具有更好的刚性,保持了良好的低温冲击性。  相似文献   

11.
Modification of polypropylene fiber was carried out by graft copolymerization of acrylonitrile monomer using the preirradiation method. The influence of synthesis conditions (preirradiation dose, monomer concentration, temperature, draw ratio, and storage) on the degree of grafting was investigated. For all preirradiation doses, the degree of grafting was found to increase with the reaction time. The higher the preirradiation dose, the higher the degree of grafting was. The dilution of monomer with DMF showed peak maxima for the degree of grafting at 80% monomer concentration. Both the initial rate of grafting and the final degree of grafting were found to increase with an increase in the reaction temperature. An activation energy of 31.2 kJ/mol was found for the grafting reaction. The degree of grafting in the drawn fiber showed different behavior as compared to the undrawn fiber. The storage of the irradiated fiber at −4°C prior to the grafting showed a decrease in the degree of grafting initially for a period of 8 days, beyond which the degree of grafting remained constant. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1343–1348, 1998  相似文献   

12.
用毛细管流变仪和DSC方法研究了马来酸酐接枝改性的聚丙烯(PP g MA)对PP/PP g MA共混体系流变性和热行为的影响。结果表明,在聚丙烯(PP)中加入固相接枝反应得到的PP g MA,在剪切应力作用下,粘度下降很快;并且该体系的熔点和熔程都有显著变化。  相似文献   

13.
用淀粉制备高分子吸水树脂的工艺研究   总被引:4,自引:0,他引:4  
介绍了一种以淀粉为基本原料、以硝酸铈铵为化学引发剂、以丙烯腈为单体制备高吸水树脂的有效方法。所得产品可吸自身重量1362倍的蒸馏水,92倍的0.9%的食盐水。  相似文献   

14.
用固相接法制得马来酸酐接枝聚丙烯,接枝率为2%~2.5%(100gPP含马来酸酐的克数),用国产XLY-Ⅱ型毛细管流变仪进行了流变性能研究。  相似文献   

15.
利用回收聚丙烯固相接枝马来酸酐(MAH)、低温等离子体等,对聚丙烯进行亲水改性研究.以亲水性的MAH作为接枝单体,探讨了单体用量及引发荆用量等因素对固相接枝反应的影响.当乙烯-醋酸乙烯酯(EVA)含量为3%时,接触角最低可降到69.6°;而等离子体可以进一步改善亲水性,使接触角最低速54.0°.  相似文献   

16.
研究了在熔融状态下,苯乙烯(St)与聚丙烯(PP)的接枝共聚反应。此反应在密炼机中进行。由红外光谱确认聚丙烯接枝苯乙烯(PP-g-PS)的生成。以二甲苯作溶剂,甲乙酮作沉淀剂,用溶解-沉淀法测定接校率。通过差示扫描量热计(DSC)测定结晶温度(Tc)和结晶度。将所制备的PP-g-PS接枝共聚物掺混进PP/SBS合金中,在PP/SBS/PP-g-PS(80:10:10)的配比下进行共混,结果表明其在室温和-25℃之下的冲击强度均比PP/SBS有明显的提高。通过动态力学测试表明接枝共聚物提高了PP与SBS的相容性。  相似文献   

17.
    
Graft copolymerization of starch has been carried out onto preirradiated polypropylene (PP) in an aqueous medium using benzoyl peroxide (BPO) as the radical initiator. The maximum percentage of grafting (115%) of starch onto PP was obtained at optimum conditions of BPO concentration, 1.239 × 10−3 moles; temperature, 65°C; in 120 min. using 30 mL of water. Swelling studies were carried out in pure, binary, ternary and quaternary solvent systems comprising of water, ethanol (EtOH), dimethylsulphoxide (DMSO), and N,N‐dimethylformamide (DMF) in different ratios. Maximum swelling is observed in DMSO and DMF, followed by EtOH and least in water for true graft. Water retention studies of pristine PP and PP‐g‐Starch (both composite and true graft) were investigated at different time periods, temperature and pH. The composite contains grafted PP, unreacted starch and unreacted PP whereas true graft is the product from which both unreacted polymers have been removed. Maximum % water retention of PP‐g‐Starch (composite) (110%) was observed in 8 h at 50°C in neutral medium (pH = 7). The graft copolymers were characterized by FTIR, DTG, DTA, TGA, and SEM. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   

18.
以蔗渣纤维为原料,丙烯酸为接枝单体,N,N-亚甲基双丙烯酰胺为交联剂,K2S2O8为引发剂,通过溶液聚合的方法合成了蔗渣纤维(sugarcanebagasse,SCB)与聚丙烯酸(polyacrylicacid,PAA)的接枝共聚高吸水树脂(scB—g—PAA)。研究了丙烯酸用量、引发剂用量、交联剂用量以及中和度对吸水树脂吸水倍率的影响,结果表明,该接枝共聚吸水树脂的最佳合成条件是以丙烯酸用量为标准,蔗渣纤维、K2S2O8、交联剂用量分别是10%、2%、0.1%,中和度为80%,共聚物吸水倍率最高为765.7g·g-1。  相似文献   

19.
    
Graft copolymerization of methyl methacrylate onto PVC was carried out using Ce(IV)–glucose redox system in aqueous sulfuric acid medium under nitrogen atmosphere. To find out the optimum conditions for grafting, effects of concentrations of metal ion, glucose, monomer, and acid on the percentage of grafting was studied. The graft yield was found to be influenced by reaction time, temperature, and amount of PVC. An appreciably high graft yield could be achieved with the present system. On the basis of the results from the present study, a plausible reaction mechanism has been proposed. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2105–2111, 2005  相似文献   

20.
聚丙烯悬浮法接枝苯乙烯的研究   总被引:7,自引:0,他引:7  
研究了聚丙烯悬浮法接枝苯乙烯,考察了聚丙烯(PP)型号、溶胀时间、反应温度、反应时间、苯乙烯(St)及过氧化苯甲酰(BPO)的浓度对St接枝率和接枝效率的影响。较佳的实验条件为:PP:St=1:1,BPO 1%,60℃溶胀2h,反应温度85~90℃,反应时间6~7h。St接枝率可达10%以上。  相似文献   

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