悬浮法合成EPDM—g—MAN接枝共聚物及其对SAN树脂的增韧作用

用悬浮接枝共聚合法合成了乙烯-丙烯-乙叉降冰片烯三元乙丙橡胶（EPDM）与甲基丙烯酸甲酯-丙烯腈（MMA—AN）共单体的接枝共聚物（EPDM—g—MAN）。将其与苯乙烯-丙烯腈共聚物（SAN树脂）共混制备了耐热氧老化黄变性能优异的高抗冲工程塑料EPDM—g—MAN／SAN共混物（AEMS）。研究了仇（AN）／m（MMA—AN）和m（EPDM）／m（MMA—AN）对5个接枝共聚体系反应行为的影响。结果发现,随着AN比率（fAN）的增加,共单体的转化率（CR）、接枝率（GR）和接枝效率（GE）都有所下降;随着m（EPDM）／m（MMA—AN）的增加,CR先增后降,GE增加,GR下降;随着优（AN）／（MMA—AN）和m（EPDM）／m（MMA—AN）的增加,AEMS的缺口冲击强度先增后降,出现极大值。AEMS在‰为5％,CR为98．9％,GR为68．4％,GE为84．6％时出现极大值,为76．8kJ／m^2。FTIR图谱显示,EPDM确已接枝上了甲基丙烯酸甲酯一丙烯腈（MAN）支链。TEM分析表明,m（EPDM）／m（MMA～AN）为55／45,fAN为10％时合成的EPDM—g—MAN在SAN树脂中以“海-岛”结构存在,相界面模糊,EPDM粒子的粒径范围为0．2～0．5μm,增韧效率高。     

悬浮法EPDM-g-MAN对SAN的增韧及其共混物的热稳定性分析

用悬浮法在乙烯-丙烯-乙叉降冰片烯三元乙丙橡胶(EPDM)上接枝甲基丙烯酸甲酯-丙烯腈(MMA-AN),将接枝共聚物EPDM-g-MAN与苯乙烯-丙烯腈共聚物(SAN)树脂共混,得到高抗冲、耐老化性能优异的工程塑料。FTIR分析表明,EPDM确已接枝上了MMA-AN支链。研究了AN含量和EPDM含量对EPDM-g-MAN/SAN共混物力学性能的影响。随着EPDM含量的增加,共混物缺口冲击强度先升后降,在AN质量分数为5%,EPDM质量分数为25%时达到最大值76.8kJ/m2,拉伸和弯曲强度逐步下降。扫描电镜(SEM)和差示扫描热(DSC)分析表明,在EPDM质量分数为15%时,共混物室温条件下受外界冲击发生脆韧转变,EPDM-g-MAN与SAN具有较好的相容性。TG分析表明,随着EPDM含量增加,EPDM-g-MAN/SAN共混物的热失重起始温度有所上升,热稳定性得到提高。     

PBA-g-SAN的表征及其对SAN树脂的增韧作用

以乳液聚丙烯酸丁酯(PBA)为主链,苯乙烯(St)和丙烯腈(An)为接枝单体,通过乳液接枝共聚合成了PBA-g-SAN接枝共聚物,用SEM、FTIR和DSC对其进行了表征。以PBA-g-SAN与SAN树脂共混制备ASA,用DSC和SEM分别对ASA及其冲击断面进行了分析。结果表明,PBA-g-SAN以平均粒径为85nm的微粒连接成珠链状的形态存在,具有高接枝率,PBA相与SAN相部分相容;PBA-g-SAN在SAN树脂中有良好的分散性,ASA存在Tg为10℃左右的界面相,使PBA相与SAN相结合紧密;当PBA质量分数为25%时,ASA的冲击断面呈“须根”结构,证实其增韧机理为剪切屈服机理。上述结构赋予ASA以高抗冲性能,其缺口冲击强度最高可达33 kJ/m2。     

悬浮接枝共聚合成POE-g-MAS及其表征

用悬浮接枝法合成了乙烯-辛烯共聚物（POE）和甲基丙烯酸甲酯（MMA）-丙烯腈（AN）-苯乙烯（St）的接枝共聚物（POE-g-MAS）。研究了单体比率、POE／单体的比率、引发剂浓度和反应时间等因素对接枝共聚合反应的影响。从聚合产物中用丙酮抽提得到接枝共聚物POE-g-MAS,并用傅立叶变换红外光谱（FTIR）和差示扫描量热法（DSC）对POE-g-MAS进行了分析。实验证明MMA-AN-St已经接枝在POE分子链上。接枝链MAS在一定程度上影响了POE的结晶相,降低了POE的熔融温度和熔融热。     

相反转乳液接枝法合成EPDM-g-SAN及其对SAN树脂的增韧作用

采用相反转乳液接枝法合成EPDM接枝聚苯乙烯-丙烯腈（EPDM-g-SAN），研究乳化剂质量分数、油相／水相（O／W）质量比和EPDM／单体质量比对聚合反应的影响以及EPDM-g-SAN对SAN树脂的增韧作用。结果表明，乳化剂质量分数为0．06、O／W质量比为100／100、EPDM／单体质量比为60／40时，聚合反应的单体转化率、接枝率和接枝效率最大；EPDM-g-SAN对SAN树脂增韧效果显著，其增韧机理以空穴化为主，兼有银纹化和剪切屈服。     

Synthesis of high rubber styrene–EPDM–acrylonitrile graft copolymer and its toughening effect on SAN

High rubber styrene–EPDM–acrylonitrile (AES) was prepared by the graft copolymerization of styrene (St) and acrylonitrile (AN) onto ethylene–propylene–diene terpolymer (EPDM) in n‐heptane/toluene cosolvent using benzoyl peroxide as an initiator. The effects of reaction conditions, such as reaction temperature, initiator concentration, EPDM content, the solvent component, and reaction time, on the graft copolymerization are discussed. In addition, according to the research on mechanical properties of the SAN/AES blend, a remarkable toughening effect of AES on SAN resin was found. By means of scanning electron microscopy, the toughening mechanism is proposed to be crazing initiation from rubber particles and shear deformation of SAN matrix. Uniform dispersion of rubber particles, as shown by transmission electron microscopy, is attributed to the good compatibility of SAN and AES. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 416–423, 2004     

丙烯酸酯类反应性微凝胶的制备及其对环氧树脂的增韧作用

采用自稳定分散聚合法,制备了粒径在20nm左右、粒径分布均匀的球形丙烯酸酯类反应性微凝胶;同时研究了其对环氧树脂/间苯二胺(MPDA)体系的增韧效果.结果表明,所制备的丙烯酸酯类反应性微凝胶在室温下呈橡胶态;它是环氧树脂/MPDA体系的一种有效增韧荆,增韧效果受其用量、官能团种类及用量的影响;含有环氧基团的微凝胶颗粒,增韧效果最好,而且提高了环氧树脂的热性能:带有环氧基团的微凝胶颗粒用量越大,或丙烯酸酯类微凝胶中环氧基团的摩尔分数越高,对环氧树脂的增韧效果越好.     

POE-g-MAS增韧SAN树脂及其相容性

合成了乙烯-辛烯共聚物(POE)和甲基丙烯酸甲酯-丙烯腈-苯乙烯的接枝共聚物(POE-g-MAS).用POE-g-MAS与苯乙烯-丙烯腈共聚物(SAN)树脂共混制备了具有高抗冲击性能的SAN,POE-g-MAS共混物,研究了接枝链极性、接枝率和POE含量对共混物冲击性能的影响,当m(St)/m(MMA)/m(An)为10:70:20,接枝率为45.1%,w(POE)为25%时,共混物的缺口冲击强度达到56.1kJ/m2.用扫描电子显微镜和差示扫描量热仪研究表明,POE-g-MAS与SAN树脂有良好的相容性.     

Synthesis of EPDM-graft-methyl methacrylate and styrene and its toughening effect on MS resin

EPDM-graft-methyl methacrylate and styrene (EPDM-g-MS), a toughen agent for MS resin, was synthesized by solution graft copolymerization of methyl methacrylate (MMA) and styrene (St) onto ethylene-proplene-diene terpolymer (EPDM) in toluene/n-heptane cosolvent using benzoyl peroxide (BPO) as an initiator. The effects of reaction conditions on the graft copolymerization were discussed. EPDM-g-MS/MS resin blends, a novel high impact engineering plastic, was prepared by melt blending EPDM-g-MS and MS resin. The toughening effect of EPDM-g-MS on MS resin was investigated. The results showed that the optimized reaction conditions were EPDM/MMA-St ratio of 50/50, MMA/St ratio of 75/25, initiator dosage of 1%, reactant concentration of 20%, toluene/n-heptane ratio of 75/25, at 80 °C for 20h, and EPDM-g-MS with the higher EPDM content (56.8%) and grafting ratio (52.8%) was obtained under the optimized reaction conditions. SEM analysis showed that EPDM-g-MS had good compatibility with MS resin. EPDM-g-MS had excellent toughening effect on MS resin and could be used for toughen agent of MS resin.     

EPDM/St‐An graft copolymerization reaction behavior by phase inversion emulsion and the toughness effect of EPDM‐g‐SAN on SAN resin

Styrene‐EPDM‐acrylonitrile tripolymer (EPDM‐g‐SAN) was synthesized by the graft copolymerization of styrene (St) and acrylonitrile (An) onto ethylene‐propylene‐diene terpolymer (EPDM) with “phase inversion” emulsification technique. The high impact strength engineering plastics AES was the blend of SAN resin and EPDM‐g‐SAN, which occupied good weathering and yellow discoloration resistivity. The effects of An percentage in comonomer and the weight proportion of EPDM to St‐An on graft copolymerization behavior and AES notched impact strength were studied. The results showed that monomer conversion ratio (CR) exhibited a peak when the An percentage changed, and the maximum value was 97.5%. Grafting ratio (GR) and grafting efficiency (GE) enhance as well. The notched impact strength of AES presented a peak with the maximum value of 53.0 KJ/m², when An percentage was at the range of 35–40%. The spectra of FTIR showed that St and An were graft onto the EPDM. DSC analysis illuminated that T_g of EPDM phase in the blends was lower than that of the pure EPDM. TEM and SEM micrographs indicated that the polarity of g‐SAN of EPDM‐g‐SAN was the main factor effect the particle morphology, in terms of size, distribution and isotropy. When weight ratio of St to An was 65/35, the polarity of g‐SAN chains was appropriate, and the EPDM‐g‐SAN particles dispersed well in the SAN matrix. The super impact toughness is interpreted in terms of EPDM phase cavitation and enhanced plastic shear yielding. The highest toughness occurs at an optimum EPDM‐g‐SAN phase particle size which is about 0.2 μm in SAN resin matrix. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

玉米淀粉/丙烯酰胺接枝型高吸水性树脂的合成

本文以硝酸铈铵为引发剂 ,研究了单体浓度、引发剂浓度、反应温度和反应时间等因素对玉米淀粉与丙烯酰胺接枝共聚制备高吸水性树脂的影响 ,通过反应条件和正交试验 ,确定了最适宜的反应条件和工艺路线 ,制备出了吸水率在 4 5 0～ 70 0g·g-1的玉米淀粉接枝型高吸水性树脂。     

有机硅接枝共聚改性环氧树脂

有机硅改性环氧树脂可提高环氧树脂的韧性和耐热性,该领域是近年来的研究热点。综述了在不消耗环氧基的前提下,通过接枝共聚引入有机硅链段改性环氧树脂的途径,介绍了改性树脂的微观形态及该领域新近研究进展。     

Synergistic toughening effect of chlorinated polyethylene and acrylic resin on SAN/ASA blends at low temperature

Styrene–acrylonitrile copolymer (SAN)/acrylonitrile–styrene–acrylate terpolymer (ASA) blends (75/25, w/w) were toughened by blending with chlorinated polyethylene (CPE) and acrylic resin (ACR) at three different temperatures (?30, 0, and 25 °C). When the testing temperature was 0 and 25 °C, CPE played a key role in improving the impact strength of blends instead of ACR. However, an obvious synergistic toughening effect of CPE and ACR was observed at ?30 °C: when both 10 phr CPE and 15 phr ACR were added, the impact strength of the blends reached a peak at 7.50 kJ/m², which was about two to three times higher than when 25 phr CPE or 25 phr ACR was introduced into the blends individually. Scanning electron microscopy, dynamic mechanical analysis, and surface energy measurements were used to investigate the toughening mechanism. Furthermore, other mechanical properties and the heat distortion temperatures were evaluated. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43958.     

Toughening effect of comonomer on acrylic denture base resin prepared via suspension copolymerization

In this article, three copolymers used as denture base resins were prepared via suspension copolymerization using butyl acrylate (BA), butyl methacrylate (BMA), or methyl acrylate (MA) with methyl methacrylate (MMA), respectively. The homopolymers and copolymers were characterized by ¹³C nuclear magnetic resonance (¹³C NMR). The influence of the three comonomers on the mechanical property was investigated in details and the fracture surfaces of copolymer specimens were examined using scanning electron microscopy (SEM). Meanwhile, the T_g values of three copolymers were examined by differential scanning calorimetry (DSC). The results indicate that, poly(methyl methacrylate) (PMMA) copolymers with BA, BMA, or MA have been successfully prepared via suspension copolymerization. The presence of BA, BMA, or MA could improve the mechanical property especially the impact strength, the toughness of the materials was remarkably improved. The toughening effect of BMA monomer is most significant. When the content of BA is 2 wt %, the flexural strength improves by 51% and the impact strength improves by 81.3%. The T_g values of three copolymers all decrease. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

几种因素对葵花秸秆髓制备高吸水树脂的研究

用葵花秸秆髓与丙烯酸(AA)和丙烯酰胺(AM)接枝共聚得到高吸水树脂,通过四组单因素实验选择出吸水倍率最高的吸水树腊的配方:m[单体总量(AA+AM)];m(秸秆)=7:1,m(引发剂),m(秸秆)=0.04,m(交联剂):m(秸秆)=0.008,反应温度为50℃.并通过实验测定发现该配方的老化年、接枝率、凝胶强度等性能明显优于淀粉类吸水树脂.     

聚氨酯预聚体的合成及其增韧环氧树脂胶粘剂的研究

EP(环氧树脂)/芳香胺胶粘剂固化体系具有良好的粘接性能和耐热性,但其固化温度较高,体系韧性较差且粘接强度不高。采用不同的异氰酸酯和聚醚多元醇按照一定的比例可合成多种端—NCO基PU(聚氨酯)预聚体,并以此作为EP的增韧改性剂。研究结果表明:当R=n(聚醚多元醇3050)∶n[HDI(六亚甲基二异氰酸酯)]=1∶2、w(PU预聚体)=10%(相对于EP质量而言)时,改性EP体系的拉伸剪切强度比未改性EP体系提高了80%。     

丙烯酸酯液体橡胶的合成及其增韧环氧树脂的研究进展

综述了反应性丙烯酸酯液体橡胶的合成方法及其用丙烯酸酯液体橡胶增韧环氧树脂的研究进展。其合成方法以溶液聚合为好,聚合产物以三元共聚物为好。增韧效果与体系的相态结构、化学键合和环氧基体的延展性有关。     

偏氯乙烯-丙烯酸甲酯悬浮共聚树脂的研制

采用悬浮共聚的方法研制了偏氯乙烯/丙烯酸甲酯（VDC/MA）共聚树脂。考察了共聚配方、分散剂种类及用量、搅拌速度及聚合温度对VDC/MA共聚树脂的影响。结果表明,当VDC/MA=（92-96）/（8-4）、采用分散剂B（用量0.13%)、搅拌速度300-400r/min,并根据聚合温度调节分子量大小,制得的VDC/MA共聚树脂其膜光泽好、透时度高,热稳定性好。     

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。