丙烯腈接枝三元乙丙橡胶共聚物增容三元乙丙橡胶/丁腈橡胶共混胶的性能

采用溶液接枝聚合法制备了丙烯腈（ACN）接枝三元乙丙橡胶（EPDM）共聚物（PAN-gEPDM）,考察了其接枝率及用量对EPDM/丁腈橡胶（NBR）共混胶物理机械性能和耐油性能的影响,并表征了PAN-g-EPDM及其增容EPDM/NBR共混胶。结果表明,ACN单体与EPDM主链发生了接枝反应,得到了不同接枝率的PAN-g-EPDM,其具有不同的热分解温度和玻璃化转变温度;当加入6份接枝率为26%的PAN-g-EPDM时,共混胶的物理机械性能及耐油性能较佳;PAN-g-EPDM可起到增容作用,使NBR相和EPDM相的相容性得到改善。     

三元乙丙橡胶/丁腈橡胶并用胶增容剂丙烯腈接枝三元乙丙橡胶共聚物的研制

采用溶液聚合法制备三元乙丙橡胶(EPDM)/丁腈橡胶(NBR)并用胶增容剂丙烯腈(AN)接枝EPDM(PANg-EPDM)共聚物,研究AN/EPDM用量比、引发剂BPO用量、溶剂种类、反应温度和反应时间对接枝率的影响。结果表明,在AN/EPDM用量比为5/6、引发剂BPO质量分数为0.005、溶剂为正庚烷、反应温度为70℃、反应时间为2.5 h的最佳溶液聚合反应条件下,PAN-g-EPDM共聚物的接枝率为26%,该接枝率的PAN-g-EPDM共聚物对EPDM/NBR并用胶增容性较好。     

聚乙烯醇与丙烯腈的接枝共聚

为了克服乙烯基单体在含氧条件下聚合的难题,在聚合过程中使用天然树胶,用硝酸铵高铈（CAN）作引发剂,在空气中进行聚乙烯醇与丙烯腈（AN）的接枝共聚反应,对天然树胶所起的作用进行研究,它的接枝百分率可由硝酸及单体含量,时间,温度的函数关系求得,其聚合速率及最大接枝率（151%）均高于在空气中制备的,甚至高于在惰性气体中不使用树胶的情况,由此可见,该树胶对接枝共聚有影响,本研究通过差式扫描量热法（DSC）检测出聚丙烯腈（PAN）的玻璃化转变温度（Tg)56℃,热重量分析（TGA）测得其热稳定性,揭示了该接枝共聚物具耐吸湿性。     

马来酸酐接枝三元乙丙橡胶改性丁腈橡胶/三元乙丙橡胶的性能研究

在转矩流变仪中通过熔融插层法制备了马来酸酐(MAH)接枝三元乙丙橡胶(EPDM)增容剂(EPDM-g-MAH)。考察了增容剂对不同并用比的丁腈橡胶/三元乙丙橡胶(NBR/EPDM)并用胶的各种性能的影响。结果表明,采用10份增容剂时,并用比为8∶2的并用胶的各项性能提升较小,使用时还需解决丁腈橡胶(NBR)的分散问题;并用比为6∶4的并用胶的各项性能有所下降,使用时需降低增容剂的添加量;并用比为7∶3的并用胶的硫化性能、耐油性能和压缩永久变形性能略有降低,但胶料的分散性、力学性能、耐热氧老化性能及耐臭氧性能均得到了显著的提升。     

溶液接枝共聚制备三元乙丙橡胶接枝共聚物的方法和应用

本发明公开一种溶液接枝共聚制备三元乙丙橡胶接枝共聚物的方法及其在制备工程塑料中的应用,该方法是在现有溶液接枝共聚法制备EPDM—g—SAN的基础上进行优化改进,     

接枝乙丙橡胶的研制

对接枝乙丙橡胶进行了制备．探讨了引发剂、调节剂、马采酸酐浓度等时接枝乙丙橡胶性能的影响。通过红外光谱对接枝产物进行了表征．结果表明：过氧化苯甲酰(BPO)为适宜的引发剂，质量分数为0．1％～0．15％；调节剂(最佳质量分数为0．5％～2％)的使用可将接枝乙丙橡胶的凝胶质量分数控制在3％以内；接枝单体质量分数1.0％～1．5％为宜。接枝产物的接枝率可迭0．8％～1.0％。     

丙烯腈-酪素在硫氰酸钠浓溶液中接枝共聚的研究

丙烯腈,酷素在硫氰酸钠浓水溶液中均相接枝共聚,研究了反应时间,单体质量分数,引发剂质量分数,反应温度对接枝共聚的影响,在共聚反应时间100min,AN12.8%,Casein5.4%,AIBN0.18%,NaSCN44%,温度72℃时,接枝率为88．4％－91．1％,产率为90．1％－91．1％,接枝效率77．4％－77．5％。     

三元乙丙橡胶—甲基丙烯酸甲酯溶胀机械接枝共聚研究

采用直接溶胀法，在叶片混合器中以不同条件制备了三元乙丙橡胶－甲基丙烯酸甲酯接枝共聚物。通过动态力学粘弹谱表征，该接枝共聚物具有稳定的双相体系相态。在适宜条件下，可以制得较好综合性能的接枝共聚物。     

溶液接枝法合成EPDM-g-SAN

以过氧化二苯甲酰(BPO)为引发剂，正庚烷／环己酮为溶剂，用溶液接枝法合成了高胶含量的苯乙烯(St)-三元乙丙橡胶(EPDM)-丙烯腈(AN)接枝共聚物(EPDM-g-SAN)。研究了反应温度、引发剂浓度、EPDM含量、混合溶剂的配比以及反应时间对接枝共聚合反应的影响。FTIR分析证实EPDM已接枝上SAN支链。实验证明，接枝共聚物对SAN树脂具有良好的增韧效果。     

苯乙烯、丙烯腈与降解天然胶乳的共聚研究

以BPO-FeSO4为氧化还原引发体系，采用种子乳液聚合技术，在降解天然胶乳DNR粒子上接枝共聚苯乙烯(St)和丙烯腈(AN)，用正交实验法研究了较佳反应条件，考察反应温度、反应时间及投料比对单体转化率、接枝率和接枝效率的影响，并用红外光谱对共聚物进行表征。     

Graft copolymerization of styrene and acrylonitrile onto EPDM

Acrylonitrile–EPDM–styrene (AES) graft copolymers were synthesized by solution graft polymerization of styrene (St) and acrylonitrile (AN) onto EPDM in an n‐hexane/benzene solvent with benzoyl peroxide (BPO) as an initiator. The structure changes were studied by an FTIR spectrophotometer. The grafting parameters were calculated gravimetrically. The influence of the polymerization conditions, such as the reaction time, concentration of the initiator, EPDM content, and weight ratio of St/AN, on the structure of the products was investigated. It was found that a proper initiator concentration and EPDM content will give a high grafting ratio of the AES resin. The thermal property of the copolymer was studied using programmed thermogravimetric analysis (TGA). The results showed that the copolymer has a better heat‐resistant property than that of ABS, especially for the initial decomposition temperature (T_in) and the maximum weight loss rate temperature (T_max). Also, the mechanism of the graft reaction was discussed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 428–432, 2002     

Graft copolymerization of acrylonitrile and methyl methacrylate monomer mixtures on crumb natural rubber

Graft copolymerization of mixtures of acrylonitrile and methyl methacylate on crumb natural rubber was carried out in toluene at 60°C. The nitrogen content of the grafted copolymer was determined by elemental analysis and used to estimate the composition of the copolymer samples. It was found that the amount of acrylonitrile monomeric units incorporated into the polymer was disproportionately lower than the acylonitrile content of the feed and explanations in terms of the e‐value of the monomers and the inherent heterogenous nature of the polymerization mixture were offered. The miscibility of the natural rubber‐g‐polyacrylonitrile‐co‐poly(methyl methacrylate) with poly(vinyl chloride) was studied by viscometry, differential scanning calorimetry, and phase contrast microscopy. It was found that the natural rubber‐g‐polyacrylonitrile‐co‐poly(methyl methacrylate) formed semimiscible blends with poly(vinyl chloride). © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1872–1877, 2002; DOI 10.1002/app.10474     

Graft polymerization of acrylonitrile onto paper and characterization of the grafted product

The chemical graft copolymerization reaction of acrylonitrile (AN) onto paper sheet was performed. The effect of initiator concentration, monomer concentration, and temperature on the reaction rate was studied. The reaction rate equation of the graft copolymerization reaction is found to be R_P = K₂ [initiator]^0.54[monomer]^1.13. The apparent activation energy (E_a) of the copolymerization reaction is found to be 35.99 KJ/mol. The infrared characteristic absorption bands for cellulosic paper structure and the paper gr‐AN are studied. Tensile break load, porosity, and burst strength were measured for the grafted and pure paper sheet. It was found that the mechanical properties are improved by grafting. The chemical resistance of the graft product against strong acid (HCl), strong alkali (NaOH), polar and nonpolar solvents was investigated. It was found that the resistance to these chemicals is enhanced by grafting. From the TGA and DTA data, it is clear that the grafted paper sheet is more thermally stable than pure paper sheet. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Ceric‐initiated free radical graft copolymerization of acrylonitrile onto kappa carrageenan

The polysaccharide, kappa carrageenan (kC), was modified using ceric‐initiated graft copolymerization of acrylonitrile (AN) under inert atmosphere in a homogeneous aqueous medium. Grafting was confirmed using FTIR spectroscopy, solubility test, elemental analysis, acid hydrolysis, and thermogravimetric analysis (TGA). kC‐graft‐poly(AN) products had a higher thermal stability than kC as revealed by TGA analysis. The polyacrylonitrile branches were isolated by acidic degradation of the carrageenan main chains and characterized by size exclusion chromatography (SEC). Residual monomers were not found by HPLC in graft copolymers stored even for longer periods. The effect of various factors affecting on grafting, i.e., concentration of the initiator, monomer, and polysaccharide as well as the reaction time and temperature were studied by conventional methods to achieve the optimum grafting parameters. The graft copolymerization reactions were kinetically investigated using semi‐empirical expressions and a suitable rate expression has been derived. According to the empirical rates of the polymerization and the graft copolymerization of AN onto kC backbone, the overall activation energy of the graft copolymerization reaction was estimated to be 20.96 kJ/mol. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

EPDM-g-SAN接枝共聚反应的研究

探讨以正庚烷 /甲苯混合物为溶剂 ,采用共聚法制备EPDM接枝聚苯乙烯 丙烯腈 (EPDM g SAN)的反应条件。试验得出的优化反应条件为 :单体苯乙烯 /丙烯腈质量比　 3 /1,EPDM/单体质量比　 45 /5 5 ,引发剂BPO浓度　3 3 8× 10 - 3mol·L- 1 ,正庚烷 /甲苯体积比　 60 /4 0 ,反应温度　 80℃ ,反应时间　 2 0h。在此条件下 ,反应的单体转化率、接枝率和接枝效率分别为 75 % ,3 3 %和 3 6%。红外光谱分析证明 ,EPDM分子链上接枝了SAN支链     

丙烯腈-三元乙丙橡胶-苯乙烯接枝共聚物AES的合成

用溶液聚合法合成了丙烯腈-三元乙丙橡胶-苯乙烯接枝共聚物（AES）,研究了接枝聚合反应的影响因素,并进行了红外光谱表征。结果表明,三元乙丙橡胶（EPDM）已接枝上丙烯腈（AN）和苯乙烯（St）的共聚物（SAN）支链,即EPDM与AN及St发生了接枝共聚合反应。     

Chemical modification of pineapple leaf fiber: Graft copolymerization of acrylonitrile onto defatted pineapple leaf fibers

Graft copolymerization of acrylonitrile (AN) onto defatted pineapple leaf fiber (PALF) was studied using a CuSO₄ and KIO₄ combination as an initiator in an aqueous medium in the temperature range 30–50⁰C. The effects of the concentration of potassium periodate, CuSO₄, and monomer on the graft yield were investigated. The effects of time, temperature, amount of some inorganic salts, and organic solvents on the graft yield are also reported. A combination of Cu⁺²—IO in an aqueous medium with an IO concentration of 0.005 mol L⁻¹ and Cu⁺² concentration of 0.002 mol L⁻¹ produced optimum grafting for use of 0.1 g defatted PALF with a fiber‐to‐liquor ratio of 1:50 at 50⁰C for 2 h. However, KIO₄ and CuSO₄ failed to induce polymerization of AN in the presence of PALF when used separately. FTIR and thermogravimetric analysis of the defatted and AN‐grafted PALF were carried out. Grafting improved the thermal stability of PALF. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 3035–3043, 2000     

Graft copolymerization onto Tamarind Kernel Powder: Ceric(IV)‐initiated graft copolymerization of acrylonitrile

Tamarind Kernel Powder (TKP) is derived from the seeds of Tamarindus indica Linn., a common and most important tree of India. It is extensively used in cotton sizing, as a wet‐end additive in the paper industry, as a thickening, stabilizing, and gelling agent in the food industry. However, because of its fast biodegradability there is a need to prepare graft copolymers of TKP. The graft copolymerization of acrylonitrile (AN) onto TKP with ceric ammonium nitrate as a redox initiator in an aqueous medium has been studied. The reaction conditions were optimized to afford maximum percent grafting and percentage grafting efficiency of AN onto TKP, which was found to be 86% and 64%, respectively. Fourier Transform Infrared Spectrum of the grafted products showed an additional sharp absorption band at 2244 cm^?1 due to ? C?N stretching, thereby confirming the grafting of AN onto TKP. Scanning electron microscopy studies indicated change in contour of the polysaccharide on grafting and the thick polymeric coating of AN on the surface alongwith grafting of AN such that all the gap between polysaccharide particles have been closed. Thermal studies using thermogravimetric and differential gravimetric analyses confirmed that TKP‐g‐AN has overall high thermal stability than pure TKP. Reaction mechanism of grafting of acrylnitrile onto TKP is also proposed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Graft mechanism of acrylonitrile onto starch by potassium permanganate

The graft mechanism of acrylonitrile (AN) onto starch under the initiation of potassium permanganate was investigated. The relationships of the grafting rate and the concentrations of potassium permanganate, AN, and backbone starch, as well as the reaction temperature, were established. On this basis, the equation for the rate of the graft copolymerization was derived, and the apparent activation energy for the graft copolymerization was obtained. Through the study of the oxidation reaction of starch with manganic ions, the valence changes of manganic ions during the graft copolymerization, and the grafting ability of different starch derivatives, together with electron spin resonance analysis, the grafting mechanism for the graft copolymerization of AN onto starch under the initiation of potassium permanganate was determined. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 146–152, 2003     

Graft copolymerization of acrylonitrile on kenaf fibers by ceric ion in the presence of allyl compounds

Graft copolymers of acrylonitrile on kenaf fibers were obtained in an aqueous medium by the use of allyl alcohol and allyl chloride in combination with ceric ion as redox pairs. The graft copolymerization reactions showed distinct features that were associated with different initiating species derived from the redox pairs. For a ceric–allyl-chloride-initiated reaction, a minimum graft yield was observed, accompanied by an enhanced graft yield. This suggested the existence of two kinetically controlled grafting reactions arising from two different initiating species. For the ceric–allyl-alcohol-initiated reaction, the grafting profile showed a maximum yield and suggested the presence of one active initiating species. High concentrations of acrylonitrile were favorable to grafting with values of up to 150%, but they also resulted in decreased efficiency in monomer conversion to grafted polymer. The frequency of grafting increased with the concentration of allyl alcohol but the molecular weight of grafted polymer of up to 4.46 × 10⁴ decreased by a factor of one and half over the concentration range 1.8–9.0 × 10⁻⁴M of the latter. The presence of 10% (v/v) N,N′-dimethylformamide resulted in zero graft, but the same vol % of formic acid had no apparent effect on the graft yield. A negative temperature dependence in the graft yield was found in the temperature range of 50–70°C. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 1757–1761, 1999