采用半连续种子乳液聚合方法制备了以聚丙烯酸正丁酯（PBA）为核、聚甲基丙烯酸甲酯（PMMA）为壳、粒径为346 nm的核/壳型改性剂（Poly（BA）/Poly（MMA））,简称PBMMA,改变两种单体的质量比分别为:60/40、65/35、75/25、70/30、80/20,以及调整添加量研究其对氰酸酯树脂（CE）的增韧改性效果。结果表明,该种子乳液聚合反应具有很高的瞬时转化率（＞ 90%）和总转化率（＞ 95%）,且改变核/壳质量比对乳液聚合反应过程没有影响。经透射电镜表征发现,PBMMA乳液有明显的核/壳结构。对CE/PBMMA共混物进行了力学性能测试,用扫描电镜观察其断裂表面形貌,并利用动态力学分析研究了CE/PBMMA共混物的分子运动。当核/壳质量比为60/40、添加量为5%（质量分数）时,增韧剂PBMMA在基体中均匀分散并出现脆性-韧性转变点。CE/PBMMA共混物的抗冲击强度是纯CE树脂的3. 78倍,力学性能与断面SEM观察结果一致。

Latex particles with the same core composition of poly(MMA-coALMA) and different shell compositions of poly(BA-co-AA) were prepared by semibatch emulsion polymerization using 'power feed' monomer and chain transfer agent addition methods in the shell layers. The seed stage involved formation of seed particles of 111 nm in diameter with a batch process. After that, two growth stages formed the final particle diameter, d(z) = 300 nm measured by dynamic light scattering. The gel content and the molecular parameters of the polymer were determined. The adhesive properties including loop tack, peel force and shear resistance were measured according to the FINAT test methods No. 9, 1 and 8. An evaluation was also made for the relationship between pressure-sensitive properties and molecular parameters. Introducing power feed to semibatch emulsion polymerization had no significant effect on the latex preparations and could improve the final conversion and the colloidal stability. The observed particles were grown without significant secondary nucleation. The power feed methods had no effect on the glass transfer temperature (T-g) of the shell layer also. Emulsion polymerization conducted by positive power feed resulted in the formation of longer primary polymer chains at the beginning than that conducted by negative power feed and standard uniform feed, which caused a very high gel fraction. As pressure-sensitive adhesives prepared by using the positive power feed had the highest gel content and strongest core-shell interaction, they exhibited the highest shear resistance, but the lowest tack and peel force.

A novel kind of thermally conductive and outstanding insulation composite was prepared using the mixture of 2-D micro-scale hexagonal boron nitride (h-BN) and 3-D nano-scale diamond (ND) hybrid fillers on the matrix of polyimide (PI) by in-situ polymerization.In order to improve the interfacial compatibility between the inorganic filler and the polymer matrix,BN fillers were functionalized with aromatic polyamide (HBP) and ND particles with 4,4'-oxybisbenzenamine (ODA).The structure and properties of the composites were characterized by scanning electron microscopy (SEM),thermo-gravimetric analysis (TGA) and thermally conductive instrument.The results indicate that the thermal conductivity of the composite can be enhanced with different sizes and types of the fillers,because of increasing the packing density,reducing the interfacial thermal resistance and forming thermal conductive networks.When the filler content is 30 ％ with the HBP-BN and ND-ODA mass ratio of 9:1,the thermal conductivity of the composite is 0.596 W/(m· K),3.5 times higher than that of the neat PI.Meanwhile,the composites fabricated possess excellent electrical insulation and thermal stability,and may be appropriate for application of the electronic materials.

A novel poly(cyclotriphosphazene-co-bisphenol A)-coated boron nitride (PCB-BN) was synthesized by in situ polymerization on the surface of BN. The epoxy/PCB-BN composites showed the enhanced thermal conductivity with the improved flame retardance.

Hexagonal boron nitride micro particles functionalized by γ-MPS, were used to fabricate PI/BN composites. The thermal conductivity of the composites with 40 wt% m-BN content was increased to 0.748 W m−1 K−1, 4.5 times higher than that of the pure PI.

Core-shell structured polyacrylic (CSSP) impact modifiers, consisting of a rubbery poly(n-butyl acrylate) core and a rigid poly(methyl methacrylate) shell, were synthesized by seed emulsion polymerization. The CSSP modifier with core-shell weight ratio 75/25 was used to modify the toughness of poly(butylene terephthalate) (PBT) by melt blending. The CSSP morphology was confirmed by TEM and SEM. Dynamic mechanical analyses of PBT/CSSP blends showed two merged transition peaks of PBT matrix. Increasing CSSP content increased elongation at break and impact strength, but decreased tensile strength. The notch impact strength of PBT/CSSP blends with weight ratio 85/15 was eight times greater than pure PBT.

采用热引发体系,以聚丙烯酸正丁酯为核层,聚甲基丙烯酸甲酯为壳层,并在最外层共聚功能单体甲基丙烯酸,以种子乳液聚合法制备了聚丙烯酸酯核-壳粒子;研究了不同核层交联密度的聚丙烯酸酯对尼龙6的增韧作用.结果表明,在乳液聚合反应中,单体转化率高,聚丙烯酸酯核-壳粒子的结构和组成可控,粒径在295 nm;当核层与壳层聚合物的质量比为85/15,核层交联剂用量和甲基丙烯酸均为单体总质量的0.5％时,尼龙6共混物的缺口冲击强度最高,是纯尼龙的7倍.

Core-shell structured polyacrylic nanoparticles (named CSPN) impact modifiers consisting of a rubbery poly(n-butyl acrylate) core and a rigid poly(methyl methacrylate) shell with a size of about 352nm were synthesized by seed emulsion polymerization. The CSPN modifier with core-shell weight ratio 80/20 was used to toughen poly(butylene terephthalate) (PBT) by melt blending. With an increase in CSPN content, the impact strength and the elongation at break of PBT/CSPN blends increased significantly compared with those of PBT; however, the tensile strength decreased. It was found that the polymerization had a very high instantaneous conversion (>93%) and overall conversion (99%). The core-shell structure of CSPN was examined by means of transmission electron microscope. Scanning electron microscope was used to observe the morphology of CSPN particle and fractured surfaces of the blends. The dynamic mechanical analyses of PBT/CSPN blends showed two merged transition peaks of PBT matrix, with the presence of CSPN modifier, which was responsible for the improvement of PBT toughness. The results indicated that the notched impact strength of PBT/CSPN blend with a weight ratio of 80/20 was 8.61 times greater than that of pure PBT where the brittle-ductile transition point appeared.

在分析了分析化学实验教学过程中遇到的一些问题的基础上,面向实际应用,采取了延伸经典实验、引入研究性实验、建立网络教学、完善考核体系等一系列教改措施,提高了学生实验技能、创新能力和应用能力,收到了较好的教学效果。

In the past work, the shear resistance of pure poly(n-butyl acrylate) was low, even incorporation of inorganic filler, silica in the composition. It is well-known that the copolymerization of n-butyl acrylate (BA) with methyl methacrylate (MMA) will increase the glass transition temperature, and enhance the shear resistance of acrylic polymers. In the current work, the preparation of a series of acrylic water-borne pressure-sensitive adhesives (PSAs) with the controlled composition and structure for the copolymerization of BA and acrylic acid (AA) with different MMA contents, poly(BA-co-MMA-co-AA) was reported and its effects on adhesive properties of the latices were investigated. The latices of poly(BA-co-MMA-co-AA) were prepared at a solid content of 50% by two-stage sequential emulsion polymerization, and this process consisted of a batch seed stage giving a particle diameter of 111 nm, which was then grown by the semicontinuous addition of monomers to final diameter of 303 nm. Dynamic light scattering (DLS) was used to monitor the particle diameters and proved that no new nucleation occurred during the growth stage. Copolymerization of BA with MMA raised the glass transition temperature (T-g) of the soft acrylic polymers, and had the effect of improving shear resistance, while the loop tack and peel adhesion kept relatively high. The relationship between pressure-sensitive properties and molecular parameters, such as gel content and molecular weight, was evaluated. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123: 1068-1078, 2012

A series of poly(n-butyl acrylate)/poly(methyl methacrylate-co-acrylic acid), i.e., poly(BA/MMA-co-AA), core-shell structured modifiers with different contents of crosslinking agent allyl methacrylate and functional monomer were prepared, and its effects on mechanical properties of polyamide 6 (PA 6) blends were investigated. The modifiers were prepared at a solid content of 50 wt% by a seeded emulsion polymerization. Dynamic light scattering measurement showed that the particle grew without significant secondary nucleation occurring. The morphology was confirmed by means of transmission electron microscopy. Scanning electron microscopy was used to observe the morphology of the fractured surfaces. The dynamic mechanical analysis measurements indicated that the appearance of two merged transition peaks and the magnitude of the loss peak of PA 6 matrix with the addition of PBMA core-shell modifier in the PA 6/PBMA blends were responsible for the improvement of PA 6 toughness. POLYM. ENG. SCI., 2012. (C) 2011 Society of Plastics Engineers

A series of acrylic copolymer latexes with different particle sizes and distribution were prepared by semi-continuous emulsion polymerization.Dynamic light scattering(DLS) was used to monitor the particle diameters,which shows that the particles have grown without significant secondary nucleation.The particle size of the latexes has decreased and the dynamic viscosity of the latexes has increased with the growing content of the surfactant at the seed stage.Dynamic mechanical analysis was used to characterize the molecular movement of the copolymers.Adhesive properties measured are loop tack force,peel strength and shear resistance according to FINAT test methods.For the two component latex system,the loop tack increases with the addition of small particle size latexes,while the shear strength decreases.For the three component latex,the peel force decreases.

The properties and morphology of nano-calcium carbonate (nano-CaCO3) modified with the titanate coupling agent isopropyl trioleoyl titanate (IPTT) were characterized by Fourier transform infrared, thermogravimetric analyses, surface tension, and transmission electron microscopy. The results showed that the grafting ratio of IPTT on the surface of nano-CaCO3 (IPTT-Ca) increased with IPTT content. IPTT-Ca/PBA/PMMA (IPTT-Ca/ACR, PBA/PMMA core-shell polymer, referred to ACR) latexes were prepared by seeded emulsion polymerization. They were then used to mix with PVC resin. The outer layer (PMMA) enhanced the dispensability of IPTT-Ca/ACR in the PVC matrix by increasing the interfacial interaction of these composite particles with PVC. The notched impact strengths of the blends were influenced by the weight ratio of IPTT-Ca to BA/MMA monomers, the weight ratio of BA/MMA. The relationships between the mechanical properties and the core-shell composite structures were elaborated. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115: 1336-1346, 2010

The polymer-supported metallocene catalyst was prepared by first copolymerization of metallocene with unsaturated double bond substituent, styrene and divinyl benzene, and then reacted with ethyl lithium, finally complexed by tetrabutyl titanate. Polymerizations of styrene were attempted in the presence of the supported metallocene catalytic system. Polymerization reactions were investigated at different polymerization conditions such as polymerization temperature,kinds of grignard reagents, Mg/Ti mole ratio and so on. The results demonstrated that catalytic activity of metallocene is increased by supported and catalytic activity of the supported catalyst is depended on the structure of copolymer-supported metallocene, polymerization conditions.

The polymer-supported metallocene catalyst was prepared by first copolymerization of metallocene with unsaturated double bond substituent styrene and divinyl benzene, and then reacted with ethyl lithium in toluene, finally complexed by tetrabutyl titanate. The catalyst structure was studied and characterized by IR, 1HNMR, ultimate analysis and photoelectron binding energy spectrum. The results showed that the supported titanium catalyst obtained from copolymerization was mainly p-substitutent functional suported tartalyst. The ICP spectrum indicated that the content of titanium was 1.19%.