甲基丙烯酸羟烷基酯与丙烯腈或丙烯酰胺共聚合的研究

测定了亲水性甲基丙烯酸羟烷基酯如HEMA、MHPMA分别与AN或AAM,在60℃不同溶剂中自由基聚合反应的竞聚率。AN(M_1)-HEMA(M_2)共单体,在DMSO或DMF溶剂以AIBN或KPS-IPA引发剂条件下共聚,用Kelen-Tüds法计算的竞聚率变化不大,r_1=0.22-0.25、r_2=0.97-1.05,说明在此均相溶液共聚中,所用的溶剂及引发剂对竞聚率的影响较小,这两种单体能很好共聚。但AAM-MHPMA或AAM-HEMA共单体时,r_1与r_2值相差很大,如前者r_1=0.0433、r_2=3.98,后者r_1=0.0535、r_2=1.89,说明不易共聚,共聚物中主要是MHPMA或HEMA组分。     

X射线光刻胶的研究

合成了甲基丙烯酸缩水甘油酯与甲基丙烯酸氯乙酯和甲基丙烯酸氯乙酯与甲基丙烯酸甲酯共聚物,并研究了该共聚物的分子量分布、结构和热稳定性能。研究了甲基丙烯酸缩水甘油酯与甲基丙烯酸氯乙酯正性X射线光刻胶。该光刻胶具有热稳定性和高分辨率性。最低线幅宽度为0.1μm。     

取代基对系列有机锡单体与MMA共聚活性的影响

本文采用红外光谱技术测定了共聚物的组成,用最小二乘曲线拟合法计算了甲基丙烯酸三甲基锡酯(TMTM),三乙基锡酯(TETM),三丁基锡酯(TBTM),和三苯基锡酯(TPTM)与甲基丙烯酸甲酯(MMA)的共聚合竞聚率,其数值分别为:r_1=1.07,r_2=0.63(TMTM/MMA);0.87,0.62(TETM/MMA);0.62,0.58(TBTM/MMA);0.68,0.60(TPTM/MMA),并计算了各单体的δ和e值,讨论了不同取代基结构对其共聚合相对活性的影响。     

4-甲基丙烯酸-2,2,6,6-四甲基哌啶醇酯自由基共聚合的研究——Ⅲ.共聚物组成与竞聚率的测定

本文以苯为溶剂,在60±0.1℃下测定了MTMP(4-甲基丙烯酸-2,2,6,6-四甲基哌啶醇酯,M_1)与St(苯乙烯,M_2)、MVK(甲基乙烯酮,M_2)、VAc(醋酸乙烯酯,M_2)、AN(丙烯腈,M_2)的共聚物组成曲线与竞聚率(MTMP-St:r_1=0.30±0.05、r_2=0.63±0.05;MTMP-MVK:r_1=0.53±0.05、r_2=0.41±0.05;MTMP-VAc:r_1=14±0.5、r_2=0.02±0.01;MTMP-AN:r_1=13.7±0.5、r_2=0.20±0.05)。确定了MTMP的Q(0.56)和e(0.49)值。讨论了共聚物结构单元的序列分布。     

Nd(vers)3/Al(i-Bu)2H/AlEt3/EASC体系催化丁二烯/异戊二烯及丁二烯/异戊二烯/月桂烯共聚合的研究

采用新癸酸钕(Nd(vers)_3)/氢化二异丁基铝(Al(i-Bu)_2H)/三乙基铝(AlEt_3)/乙基倍半氯化铝(EASC)体系催化丁二烯(Bd)/异戊二烯(Ip)及Bd/Ip/月桂烯(My)共聚合.所得丁戊共聚物组成与催化剂用量无关,单体的投料量与共聚物中此单体的含量几乎呈线性关系;用示差扫描量热仪(DSC)测得共聚物只有一个玻璃化转变,共聚物中Ip含量与其玻璃化转变温度(T_g)呈良好的线性关系.采用Fineman-Ross方法计算竞聚率得到r_1=1.04,r_2=1.18,Kelen-Tüdos法计算竞聚率得到r_1=1.33,r_2=1.59;r_1,r_2均接近于1,说明在此催化体系下反应可以得到无规的丁戊共聚物.利用核磁碳谱对共聚物的序列结构进行了分析和归属,采用Bernoulli模型和一级Markov模型验证共聚物的序列结构,通过比较数均序列长度,一级Markov模型计算得到的序列长度与核磁计算的实际值更接近. Bd/Ip/My三元共聚合时,所得共聚物中My单元含量随着投料比的增加而增加,其DSC曲线上只有一个玻璃化转变,T_g值随着My含量的增加而稍增加.     

红外光谱法测定St—BMA的竞聚率

对于共聚合反应中同一对单体的竞聚率,由于采用的实验方法、计算方法不同,可能有几对、甚至上百对不同的数据。在实际生产中已逐渐趋向于在较高温度下进行共聚合,而文献的竞聚率一般均在较低温度下获得,因此缺乏实用意义。本文用FTIR方法测定苯乙烯(St)-甲基丙烯酸正丁酯(BMA)共聚竞聚率参数r_1和r_2,讨论了温度的影响。     

甲基丙烯酸三丁基锡酯与丙烯酸酯的共聚合

采用自由基引发剂对甲基丙烯酸三丁基锡酯和丙烯酸酯进行共聚合 ,其竞聚率用YBR法解出共聚方程的微分式而求得。甲基丙烯酸三丁基锡酯 (M1 )和丙烯酸甲酯 (M2 )、丙烯酸乙酯 (M2 )、丙烯酸丁酯 (M2 )共聚反应的竞聚率分别为r1 =1 .0 1± 0 .0 6,　r2 =0 .2 9± 0 .0 3;　r1 =1 .0 7± 0 .0 5 ,r2 =0 .38± 0 .0 3;　r1 =1 .1 1± 0 .0 5 ,　r2 =0 .45± 0 .0 3;　而所得到的甲基丙烯酸三丁基锡酯的Q、e值是它对各个单体的所有Q、e值的平均值 ,其Q =0 .5 7,e=- 0 .39     

含卤高聚物记录材料的研究——不同共聚单体对紫外光敏性的影响

研究了与偏二溴乙烯(VDBr,M_1)共聚的不同单体(M_2)——丙烯酸甲酯(MA)、甲基丙烯酸甲酯(MMA)和苯乙烯(St)的性质和共聚物的序列分布对记录材料紫外光敏性的影响。结果表明,含St的紫外光敏性最高,含MA的较差。对同一类共聚物记录材料而言,光敏性与共聚物的序列分布,主要是P_2(M_1M_2)有对应关系。本文还报道了VDBr与MA、MMA及St在55±0.2℃以偶氮二异丁腈为引发剂的自由基共聚反应竞聚率(r)分别为,VDBr-MA:r_1=0.72±0.05,r_1=0.72±0.05;VDBr-MMA:r_1=0.50±0.04,r_2=1.74±0.04;VDBr-St:r_1=0.40±0.04,r_2=1.12±0.04。     

2-甲基-7-亚甲基-1,4,6-三氧螺[4,4]壬烷与丙烯腈、丙烯酸甲酯的共聚合反应及竞聚率的测定

用高效液相色谱跟踪2-甲基-7-亚甲基-1,4,6-三氧螺[4,4]壬烷(MMTN)与丙烯腈(AN),丙烯酸甲酯(MA)的共聚合反应。根据Lowry-Meyer共聚积分方程式,采用插值法进行数据拟合测定单体的竞聚率。对于体系MMTN(M_1)-AN(M_2),r_1=0.048;r_2=0.213;MMTN(M_1)-MA(M_2)r_1=0.025,r_2=0.764。说明两组共聚体系均有较强的交替共聚趋势。     

pH响应性含氟三嵌段共聚物的制备及性质研究

以苄醇(BzOH)与氢化钾(KH)反应形成的氧阴离子作为引发剂, 依次引发甲基丙烯酸-2-(N,N-二甲氨基)乙酯(DMAEMA, 简称DMA)、甲基丙烯酸-2-(N,N-二乙氨基)乙酯(DEAEMA, 简称DEA)和甲基丙烯酸-(2,2,3,3,4,4,5,5-八氟)戊酯(OFPMA)进行氧阴离子聚合, 获得含氟三嵌段共聚物PDMA-b-PDEA-b-POFPMA和PDEA-b-PDMA-b-POFPMA. 共聚物的化学结构可以通过不同单体的加料顺序和各种单体的投料量加以控制. 通过¹H NMR, ¹⁹F NMR和GPC测试, 研究聚合物的结构、分子量及分子量分布. 利用表面张力、荧光探针法、Zeta电位和透射电镜等测试方法, 研究共聚物在不同pH值的水溶液中的聚集行为.     

甲基丙烯酸酯和丙烯酸酯基团转移共聚的竞聚率

甲基丙烯酸酯和丙烯酸酯基团转移共聚的竞聚率邹友思郭金全戴李宗潘容华（厦门大学化工系，厦门，３６１００５）基团转移聚合是制备极性单体的嵌段或无规共聚物的有效方法。如用甲基丙烯酸甲酯（ＭＭＡ）和丙烯酸丁酯（ＢＡ）进行嵌段共聚，可制得热塑性弹性体［１...     

Copolymerization of 2-Hydroxypropyl Methacrylate with Alkyl Met hacrylates

2-Hydroxypropyl methacrylate (2-HPMA) has been copolym-erized with ethyl methacrylate (EMA), n-butyl methacrylate (BMA), and 2-ethylhexyl methacrylate (EHMA) in bulk at 60°C using benzoyl peroxide as initiator. The copolymer composition has been determined from the hydroxyl content. The reactivity ratios have been calculated by the Yezrielev, Brokhina, and Raskin method. For copolymerization of 2-HPMA (M₁) with EMA (M₂), the reactivity ratios are r₁ = 1.807 ± 0.032 and r₂ = 0.245 ± 0.021; with BMA (M₂) they are n = 2.378 ± 0.001 and r₂ = 0.19 ± 0.01; and with EHMA the values are r₁ = 4.370 ± 0.048 and r₂ = 0.103 ± 0.006. Since reactivity ratios are the measure of distribution of monomer units in copolymer chain, the values obtained are compared and discussed. This enables us to choose a suitable copolymer for synthesizing thermoset acrylic polymers, which are obtained from cross-linking of hydroxy functional groups of HPMA units, for specific end-uses.     

Copolymerization of 2-Hydtoxypropyl Methacrylate with Alkyl Methacrylates

2-Hydroxypropyl methacrylate (2 HPMA) has been copolym-erized with ethyl methacrylate (EMA), n-butyl methacrylate (BMA), and 2-ethylhexyl methacrylate (EHMA) in bulk at 60°C using benzoyl peroxide as initiator. The copolymer composition has been determined from the hydroxyl content. The reactivity ratios have been calculated by the YBR method. For copolymerization of 2-HPMA (M₁) with EMA (M₂), the reactivity ratios are: r₁=1.807 ± 0.032, r₂=0.245 ± 0.021; with BMA (M₂) they are r₁=2.378 ± 0.001, r₂=0.19 ± 0.01; and with EHMA the values are r₁=4.370 ± 0.048, r₂=0.103 ± 0.006. Since the reactivity ratios are the measure of distribution of monomer units in a copolymer chain, the values obtained are compared and discussed. This enables us to choose a suitable copolymer for synthesizing thermoset acrylic polymers, which are obtained from cross-linking of hydroxy functional groups of HPMA units, for specific end uses.     

丙烯酸甲酯/4-丙烯酰胺基-2,2,6,6-四甲基哌啶光共聚合体系的竞聚率和序列分布研究

以丙烯酸甲酯(MA,M1)和4-丙烯酰胺基-2,2,6,6-四甲基哌啶(AATP,M2)溶液光共聚合体系为研究对象,采用1H-NMR手段测定了MA/AATP共聚物的组成,用Mayo-Lewis积分法和扩展Kelen-Tüdos方法计算的竞聚率分别为0.88相似文献   

Radiolysis of polymers of chlorine methacrylates

Polymers of α-chloroacrylate (MCA), 1-chloroethyl methacrylate (1CEMA), 2-chloroethyl methacrylate (2CEMA), 2,2,2-trichloroethyl methacrylate (trCEMA) and 1,2,2,2-tetrachloroethyl methacrylate (teCEMA) were γ-irradiated at 77 K. The primary radicals were generated by the abstraction of chlorine. They decay or change into chain end radicals upon warming up to room temperature.     

Effect of LiClO4 Salt on Dielectric Properties of Acrylonitrile-Methyl Methacrylate and Acrylonitrile-Isobutyl Methacrylate Copolymers

Poly(acrylonitrile-co-isobutyl methacrylate), PAN-co-PIBMA, and poly(acrylonitrile-co-methyl methacrylate), PAN-co-MMA copolymers are synthesized by emulsion polymerization. The structural characterization is done by FTIR and ¹H-NMR spectroscopy and thermal analyses are performed by thermogravimetric analysis (TGA). After various amounts of LiClO₄ salt loading into copolymer films, the dielectric properties of these films at different temperatures and frequencies are determined. The effects of different methacrylate groups and salt content on the dielectric properties of copolymers are investigated. It is found that the dielectric constant increases systematically with increasing MMA and IBMA content in the copolymer. The samples with higher salt content show higher ac-conductivities.     

Copolymerization of Tri-n-butyltin Acrylate and Tri-n-butyltin Methacrylate Monomers with Vinyl Monomers Containing Functional Groups

A new approach to obtaining thermoset organotin polymers, which permits control of crosslinking site distribution and, through it, a better control of properties of organotin antifouling polymers, is reported. Tri-n-butyltin acrylate and tri-n-butyltin methacrylate monomers were prepared and copolymerized, by the solution polymerization method with the use of free-radical initiators, with several vinyl monomers containing either an epoxy or a hydroxyl functional group. The reactivity ratios were determined for six pairs of monomers by using the analytical YBR method to solve the differential form of the copolymer equation. For copolymerization of tri-n-butyltin acrylate (M₁) with glycidyl acrylate (M₂), these reactivity ratios were n = 0.295 ± 0.053, r₂ = 1.409 ± 0.103; with glycidyl methacrylate (M₂) they were r₁ = 0.344 ± 0.201, r₂ = 4.290 ± 0.273; and with N-methylolacrylamide (M₂) they were r₁ = 0.977 ± 0.087, r₂ = 1.258 ± 0.038. Similarly, for the copolymerization of tri-n-butyltin methacrylate (Mi) with glycidyl aery late (M₂) these reactivity ratios were r₁ = 1.356 ± 0.157, r₂ = 0.367 ± 0.086; with glycidyl methacrylate (M₂) they were r₁ = 0.754 ± 0.128, r₂ = 0.794 ± 0.135; and with N-methylolacrylamide (M₂) they were r₁ ?4.230 ± 0.658, r₂ = 0.381 ± 0.074. Even though the magnitude of error in determination of reactivity ratios was small, it was not found possible to assign consistent Q,e values to either of the organotin monomers for all of its copolymerizations. Therefore, Q,e values were obtained by averaging all Q,e values found for the particular monomer, and these were Q = 0.852, e = 0.197 for the tri-n-butyltin methacrylate monomer; and Q = 0.235, e = 0.401 for the tri-n-butyltin acrylate monomer. Since the reactivity ratios indicate the distribution of the units of a particular monomer in the polymer chain, the measured values are discussed in relation to the selection of a suitable copolymer which, when cross-linked with appropriate crosslinking agents through functional groups, would give thermoset organotin coatings with an optimal balance of mechanical and antifouling properties.     

Copolymerization of N-Vinylcarbazole with 2-Dimethylaminoethyl Methacrylate

The thermal copolymerization of N-vinylcarbazole (VCz) with 2-dimethylaminoethyl methacrylate (DMAEM) initiated by α,α′-azobisisobutyronitrile (AIBN) in solution in tetrahydrofuran at 60°C has been studied. Different compositions of copolymer were prepared and characterized by UV, IR, and ¹H-NMR spectroscopy, viscosity measurements, and thermal studies. The estimation of the composition of VCz and DMAEM in the copolymer was carried out by UV spectroscopy. The reactivity ratio of VCz (r ₁) and DMAEM (r ₂) was determined by the methods of Mayo and Lewis, Kelen and Tüdös, and Tidwell and Mortimer.     

3-Tetrahydrofurfuryloxy-2-Hydroxypropyl Methacrylate: Synthesis,Characterization, Homopolymerization,and Copolymerization

Abstract

3-Tetrahydrofurfuryloxy-2-hydroxypropyl methacrylate monomer was prepared from methacrylic acid, tetrahydrofurfuryl alchol, and epichlorhydrin. Homopolymerization and copolymerization with (2-phenyl-1,3-dioxolane-4-yl)methyl methacrylate and N-vinyl pyrrolidone monomers were carried out in 1,4-dioxane solution at 60°C using benzoyl peroxide as initiator. Infrared, proton and carbon-13 nuclear magnetic resonance techniques were used in characterizations of the monomer, the homopolymer and the copolymers were determined by DSC technique. The copolymer compositions were estimated from 1H-NMR spectra. The reactivity ratios in copolymerization of 3-tetrahydrofurfuryloxy-2-hydroxypropyl methacrylate and (2-phenyl-1,3-dioxolane-4-yl) methyl methacrylate were calculated by both Kelen-Tüdos and Fineman-Ross methods.