sPS/PBA-aPS共混物的结晶与熔融行为

通过熔融共混法制备了间规立构聚苯乙烯/聚丙烯酸丁酯无规立构聚苯乙烯核壳乳胶粒子（sPS/PBA-aPS）共混物,采用差示扫描量热仪、X射线衍射仪和偏光显微镜研究了PBA-aPS对sPS结晶性能、结晶形态的影响,以及共混物在不同降温速率下、等温结晶条件下所得试样的熔融行为。结果表明, PBA-aPS的引入对sPS的结晶起阻碍作用,sPS及其共混物存在明显熔融重结晶再熔融现象,sPS平衡熔点为293.2 ℃,共混物的平衡熔点随PBA-aPS含量增加而降低,sPS形成β型大球晶完善性变差,sPS/PBA-aPS共混物的冲击强度明显提高,sPS/PBA-aPS质量比为80:20时,冲击强度提高了117 %。     

sPS/PBA-aPS共混物的非等温结晶动力学

采用差示扫描量热仪(DSC)研究了间规立构聚苯乙烯/聚丙烯酸丁酯-无规立构聚苯乙烯核壳乳胶粒子(sPS/PBA-aPS)共混物非等温结晶及其动力学。通过Jeziorny法和Mo法分别对s PS/PBA-aPS共混物的非等温结晶过程进行了分析处理,结果表明:随着降温速率增加,s PS结晶时间变短,结晶不完善程度增加;PBA-aPS核壳乳胶粒子的引入对sPS结晶起阻碍作用,Jeziorny法和Mo法都适用于分析sPS/PBA-aPS共混物的非等温结晶过程。     

SEBS弹性体增韧改性PE-HD/PS共混物及其相容性研究

采用聚苯乙烯嵌段聚（乙烯亚丁基）嵌段聚苯乙烯（SEBS）弹性体增韧改性高密度聚乙烯（PE-HD）/聚苯乙烯（PS）共混物,通过哈克转矩流变仪制备了PE-HD/PS/SEBS三元共混物,采用扫描电子显微镜（SEM）、旋转流变仪、冲击试验机、热重分析仪（TG）和差式扫描量热仪（DSC）等手段研究了PE-HD/PS/SEBS共混体系的相容性。结果表明,SEBS对共混体系具有良好的增容作用,但当SEBS添加量大于8 %(质量分数,下同)后,部分SEBS出现团聚现象,导致共混体系相容性降低;SEBS的引入对共混物的耐热性影响不大,共混物中连续相PE-HD的熔点稍有降低;随着SEBS添加量的增加,共混物的悬臂梁缺口冲击强度大幅提高。     

PC/HBPS共混体系相容性的研究

通过熔融共混法制备了聚碳酸酯／高支化聚苯乙烯（PC／HBPS）共混物,用差示扫描量热（DSC）仪和扫描电子显微镜（SEM）研究了其相容性。结果表明,采用不同的测试方法得到的共混体系各组分的相容性结果不同。用DSC分析,HBPS的质量分数小于等于1．5％时,PC／HBPS共混物只有一个玻璃化转变温度（t）,为完全相容体系;在PC中共混质量分数2．0％的HBPS时,共混物具有两个t,为部分相容体系。用SEM分析,HBPS的质量分数小于等于2．0％时,PC／HBPS共混物呈两相结构,HBPS以近似球状粒子均匀地分布在连续相PC中,相界面模糊,具有部分相容性。     

长支链聚丙烯增容聚丙烯共混物的研究

以聚丙烯（PP）为原料,通过熔融接枝法制备长支链聚丙烯（LCBPP）,将LCBPP分别加入到PP／聚苯乙烯（PS）、PP／苯乙烯-丙烯腈嵌段共聚物（SAN）和PP／聚对苯二甲酸乙二醇酯（PET）共混体系里。采用傅里叶变换红外（FTIR）和拉伸流变仪对LCBPP进行表征。采用扫描电子显微镜对共混物的断面进行观察。结果表明,LCBPP对分散相具有一定极性的体系表现出良好的增容效果;在组分比为70/30的PP/SAN 和PP/PET体系中加入５％的LCBPP后,体系分散相尺寸明显细化且分散均匀,但是其增容效果没有枝马来酸酐接聚丙烯（PP-g-MAH）的增容效果明显;LCBPP对于PP/PS体系的相容性有轻微的改善。     

间规聚苯乙烯/等规聚丙烯共混物的热性能

用差示扫描量热法(DSC)、动态力学分析(DMA)和热重法(TGA)等研究了间规聚苯乙烯/等规聚丙烯(sPS/iPP)、sPS与聚-1-丁烯(B30)组成的嵌段共聚物和sPS/iPP/B30共混体系的热性能。结果表明sPS/iPP是不相容体系,B30与iPP可相容,B30可作为sPS/iPP共混物的相容剂。DSC和DMA分析结果表明,加入适量的B30时,sPS/iPP/B30共混物中iPP的玻璃化转变温度随B30加入量的增加而逐渐升高,而sPS的玻璃化转变温度则随B30加入量的增加而逐渐降低;TGA分析结果表明共混体系的热失重温度高于300℃,比iPP的高。     

间规聚苯乙烯/高抗冲聚苯乙烯共混物相容性研究

通过熔融共混挤出制备了间规聚苯乙烯/高抗冲聚苯乙烯(PS-s/PS-HI)共混物,通过差示扫描量热(DSC)仪、动态热机械分析(DMA)仪、扫描电子显微镜(SEM)考察了PS-s/PS-HI共混物的相容性.结果表明,PS-s/PS-HI共混物中PS-s与PS-HI中的PS相是相容的;DMA结果表明,PS-HI可提高PS...     

相反转工艺制备聚苯乙烯/聚酯共混物微球

通过相反转工艺制备了聚苯乙烯/聚酯共混物微球,采用差示扫描量热仪、扫描电子显微镜、粒度分析仪研究了共混物微球的玻璃化转变温度、微观形貌、粒径等,分析了分散剂、表面活性剂、搅拌速率对共混物微球粒径及其分布的影响。结果表明:共混物微球具有两个玻璃化转变温度,与聚苯乙烯和聚酯的玻璃化转变温度相比,共混物微球的两个玻璃化转变温度相互靠近;聚酯和聚苯乙烯构成不相容体系,但二者链段间具有部分相容性;共混物微球表面粗糙;聚乙烯醇可有效减缓聚合过程中单体相粒子间发生聚并;微球粒径随表面活性剂用量、搅拌速率增加而减小,且粒径分布变窄。     

PTT/sPS共混物的形态和结晶行为

经双螺杆挤出机熔融挤出制备了聚对苯二甲酸丙二酯(PTT)/间规聚苯乙烯(sPS)/共混物,研究了共混物的微观形态、晶体结构、结晶与熔融行为。结果表明,PTT/sPS共混物属部分相容体系,sPS以规则小球分布在PTT基体中,使PTT的结晶温度和结晶度均有提高,但不影响PTT的晶体结构;PTT使sPS的冷结晶峰降低、熔体降温结晶温度提高;共混物中sPS在冷结晶下只形成α晶型,在熔体降温结晶下形成α晶型和部分β晶型。     

PLA-b-PMMA嵌段结构对PC/PLA共混形态和性能的影响

制备了具有不同嵌段长度的聚乳酸b聚甲基丙烯酸甲酯（PLA-b-PMMA),并将其作为大分子相容剂用于聚碳酸酯/聚乳酸（PC/PLA）共混体系,研究嵌段结构对PC/PLA共混体系形态与性能的影响。用傅里叶红外光谱仪和核磁共振氢谱表征嵌段共聚物的结构,用差示扫描量热仪、扫描电子显微镜和力学性能测试表征共混体系的结构及性能。结果表明,PLA-b-PMMA的加入改善了PC与PLA之间的相容性,其增容效果取决于PLA-b-PMMA的添加量及两嵌段的长度;当PLA-b-PMMA添加量为6 %时,PC与PLA之间的相容性较好;在PMMA嵌段长度一定时,随着PLA链段长度从3390提高到9780,共混体系中两相的相容性不断改善,共混物的力学性能增强;在PLA嵌段长度一定时,随着PMMA链段长度从20680提高到99680,增容效果逐渐下降。     

Preparation and characterization of composite resin by vinyl chloride grafted onto poly(BA-EHA)/poly(MMA-St)

Crosslinked poly(butyl acrylate-co-2-ethylhexyl acrylate)/poly(methyl methacrylate-co-styrene) (ACR I) latex was synthesized by multi-stage emulsion polymerization. A series of grafting vinyl chloride (VC) composite latices were prepared by emulsion copolymerization in the presence of core-shell ACR I latex. The effects of ACR I amount and its core/shell ratio on particle diameters of the composite latices and mechanical properties of the prepared materials were investigated. The grafting efficiency (GE) of VC grafted onto ACR I increases with an increasing ACR I content. Transmission electron microscope (TEM) study indicates that ACR I latex particles have a regular core-shell structure obviously. However, when styrene content in the shell of ACR I is more than 70 percent of the shell by weight, ACR I latex particles have an irregular core-shell morphology like sandwich. The composite latex particles synthesized by core-shell ACR I latex grafting VC have a clear three-layered core-shell structure. Dynamic mechanical analysis (DMA) study reveals that the compatibility between ACR I and PVC is well improved. With increasing ACR I content, the loss peak in low temperature range for every composite sample becomes stronger and stronger and gradually shifts to a higher temperature. Scanning electron microscope (SEM) graphs showed that the fractured surface of the composite sample exhibited better toughness of the material. TEM graphs showed that ACR I was uniformly dispersed in the PVC matrix.     

聚苯乙烯-聚甲基丙烯酸甲酯核-壳粒子的制备

由种子乳液聚合法制备了聚苯乙烯-聚甲基丙烯酸甲酯核-壳粒子。以过硫酸钾(KPS)为引发剂,辛基酚聚氧乙烯醚(OP-10)为乳化剂,合成了聚苯乙烯(PS)种子核;连续滴加甲基丙烯酸甲酯(MMA),在核表面富集MMA,制备了粒径范围在0.16~0.67μm的核-壳粒子;当单体苯乙烯与甲基丙烯酸甲酯(St/MMA)的比为30∶70(质量比)时,所得粒径在0.18μm,粒径分布为0.012。差示扫描量热(DSC)研究显示,复合粒子的玻璃化转变温度(Tg)为97.2℃,峰形单一,表现出良好的热性能。     

Synthesis of core-shell emulsion copolymer of poly(butyl acrylate)/α-methyl styrene-co-methyl acrylate,with application as processing aid of poly(vinyl chloride)

The core-shell grafting copolymer of α-methyl styrene-methyl acrylate on poly(butyl acrylate) was synthesized. The particle morphology of latex and core-shell grafting polymerization was investigated as a function of: (a) reaction temperature; (b) initiator concentration used in the secondary polymerization; (c) monomer to polymer ratio; (d) emulsifier concentration. The compatibility of this copolymer with poly(vinyl chloride) (PVC) was determined by the method of solubility parameter and scanning electron microscopy. The rheological behavior of the blend of this copolymer with PVC was investigated. The mechanical properties of the blend were determined. The results show that this copolymer can be used as processing aid for PVC. © 1994 John Wiley & Sons, Inc.     

n-BMA/MMA共聚核壳乳液的合成研究

通过半连续种子乳液聚合的方法,制备了具有核壳结构的丙烯酸酯聚合物乳胶粒子。采用甲基丙烯酸甲酯(MMA)、甲基丙烯酸酯正丁酯(n-BMA)等单体进行共聚。研究了共聚合过程中,乳化剂浓度、引发剂等对聚合物乳液粒径大小、凝胶量等的影响,并利用动态光散射(DLS)、透射电镜(TEM)和差示扫描量热仪(DSC)对乳胶粒子进行表征。结果表明:核乳液聚合阶段乳化剂浓度增大,乳液粒子的粒径变小,引发剂用量对粒径及分布影响不大;TEM观察到核乳胶粒径大小及变化趋势与DLS测得的结果相一致,并且核乳胶粒子和核壳乳液粒子都呈规则的圆球状,分布均一;DLS测试核壳丙烯酸酯乳胶粒子粒径的变化呈逐渐增长的趋势;DSC测试发现制备的核壳粒子有2个玻璃化转变温度(Tg),验证了胶乳粒子核壳结构的存在。     

Miscibility, crystallization and morphologies of syndiotactic polystyrene blends with isotactic polystyrene and with atactic polystyrene

Two-component blends of differing polystyrene (PS), one syndiotactic (sPS) and the other isotactic (iPS) or atactic (aPS), were discussed. The phase behavior, crystallization and microstructure of binary polystyrene blends of sPS/iPS and sPS/aPS with a specific composition of 5/5 weight ratio were investigated using optical microscopy (OM), differential scanning calorimetry, wide-angle X-ray diffraction, scanning and transmission electron microscopy (SEM and TEM). Based on the kinetics of enthalpy recovery, complete miscibility was found for the sPS/aPS blends where a single recovery peak was obtained, whereas phase separation was concluded for the sPS/iPS blends due to the presence of an additional recovery shoulder indicating the heterogeneity in the molten state. These findings were consistent with OM and SEM observations; sPS/iPS exhibits the dual interconnectivity of phase-separated phases resulting from spinodal decomposition.Both iPS and aPS have the same influence on the sPS crystal structure, i.e., dominant β-form sPS and mixed α-/β-form sPS obtained for melt-crystallization at high and low temperatures respectively, but imperfect α-form sPS developed when cold-crystallized at 175 °C. Co-crystallization of iPS and sPS into the common lattice was not observed regardless the thermal treatments, either cold or melt crystallization. Due to its slow process, crystallization of iPS was found to commence always after the completion of sPS crystallization in one-step crystallization kinetics. Segregation of rejected iPS component during sPS crystallization was extensively observed from TEM and SEM images which showed iPS pockets located between sPS lamellar stacks within spherulites, leading to the interfibrillar segregation, which was similar with that observed in the sPS/aPS blends. The addition of iPS (or aPS) component will reduce the overall crystallization rate of the sPS component and the retardation of crystal growth rates can be simply accounted by a dilution effect, keeping the surface nucleation intact. The phase-separated structure in the sPS/iPS blend shows a negligible effect on sPS crystallization and the signature of phase separation disappears after sPS crystallization. Depending on the relative dimensions of the segregated domains and iPS lamellar nucleus, subsequent crystallization of iPS can proceed to result in a crystalline/crystalline blend, or be inhibited to give a crystalline/amorphous blend morphology similar with that of sPS/aPS blends.     

Film formation from pigmented latex systems: Drying kinetics and bulk morphologies of ground calcium carbonate/functionalized poly(n‐butyl methacrylate‐co‐n‐butyl acrylate) blend films

The drying kinetics and bulk morphology of pigmented latex films obtained from poly(n‐butyl methacrylate‐co‐n‐butyl acrylate) latex particles functionalized with carboxyl groups and ground calcium carbonate blends were studied. Latex/pigment blends with higher carboxyl group coverage on the latex particle surfaces dried faster than films with few or no carboxyl groups present. The latex/pigment dispersions also dried faster when there was more stabilizer present in the blend system because of the hydrophilic nature of the stabilizer. The net effect of increasing the pigment volume concentration in the blend system was to shorten the drying time. The bulk morphologies of the freeze‐fractured surfaces of the pigmented latex films were studied with scanning electron microscopy. Scanning electron microscopy analysis showed that increased surface coverage of carboxyl groups on the latex particles in the latex/pigment blends resulted in the formation of smaller pigment aggregates with a more uniform size distribution in the blend films. In addition, the use of smaller latex particles in the blends reduced the ground calcium carbonate pigment aggregate size in the resulting films. Scanning electron microscopy analysis also showed that when the initial stabilizer coverage on the latex particles was equal to 18%, smaller aggregates of ground calcium carbonate were distributed within the copolymer matrix of the blend films in comparison with the cases for which the initial stabilizer coverage on the latex particles was 8 or 36%. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2267–2277, 2006     

电场作用下磺化聚苯乙烯微球在弹性体中梯度结构构建及性能研究

先采用硫酸对聚苯乙烯微球经过磺化得到带正电荷的磺化聚苯乙烯(s PS),将s PS分散在聚二甲基硅氧烷(PDMS)预聚体中,在高压直流电场下通过电泳作用形成梯度结构,再通过PDMS的热固化后将梯度结构固定下来。采用马尔文Zeta电位仪分析了s PS微球电荷,扫描电镜(SEM)对s PS以及s PS/PDMS梯度膜的结构进行表征,动态热机械分析仪测试了材料的动态力学行为和介电损耗。结果表明,电压强度为500 V/mm时,s PS能够在PDMS预聚体中通过电泳作用形成梯度结构,s PS总质量分数为20%时,s PS/PDMS梯度膜相比相同组成的均匀膜断裂伸长率提高了9. 41%,损耗因子在所测得温度范围(-70~200℃)均提高。在s PS的玻璃化转变温度附近,s PS/PDM S梯度膜比均匀膜损耗因子提高了30%。进一步对梯度结构膜力学行为及介电损耗增强效应进行了详细分析。     

纳米SiO2/聚氨酯-含氟丙烯酸酯杂化乳液的合成与表征

采用种子乳液聚合法,以聚氨酯（PU）乳液为种子（在聚合过程中为壳相）,甲基丙烯酸甲酯（MMA）、丙烯酸丁酯（BA）、甲基丙烯酸十二氟庚酯（DFMA）和γ-甲基丙烯酰氧丙基三甲氧基硅烷（KH-570）改性的纳米SiO₂组成的混合物为核相,合成了具有核壳结构的纳米SiO₂/聚氨酯-含氟丙烯酸酯（SiO₂/FPUA）复合乳液。考察了纳米SiO₂和DFMA用量对乳液聚合过程及乳胶膜性能的影响。通过傅里叶红外光谱（FT-IR）、接触角（CA）、透射电子显微镜（TEM）、热重（TG）、差示扫描量热仪（DSC）和力学性能测试（MPT）等表征乳液的结构形态、乳胶膜的表面性能和综合性能。结果表明：乳胶粒子呈现“反相核壳”结构,以聚丙烯酸酯（PA）相为核,PU相为壳;由于纳米SiO₂和DFMA的协同作用,涂膜的疏水性和综合性能得到了较大的提高。     

AIM增韧剂的合成及其增韧PVC的研究

采用种子乳液聚合法合成了核-壳结构丙烯酸酯类冲击改性剂(AIM),并用其增韧聚氯乙烯(PVC)树脂。采用动态激光粒度分析仪、DMA测试了AIM的乳胶粒子尺寸和玻璃化转变温度。对PVC/AIM共混物力学性能的分析表明:当PVC/AIM=100/8时,通过调节AIM交联剂含量和粒子尺寸,可以使PVC/AIM共混物冲击强度达到1443J/m。