Sequence distribution in the Living anionic copolymerization of Styrene and strong electron-donating DPE derivative, i.e. the 1,1-bis(4-N,N-dimethylanimophenyl) ethylene (DPE-(NMe2)(2)), was investigated by a timing-sample method. The target taken samples were characterized by SEC and H-1 NMR in detail According to the research data based on integrating all the taken samples, the synthesized copolymer exhibited gradient structure that most polar dimethylamino groups distributed at the end section along whole polymer chains. In addition, the apparent rate constants of styrene and DPE-(NMe2)(2) were calculated (at 24 degrees C) as follows: K-st = 0.036 min(-1) (R-2 = 0.995), K-DPE = 8.40 x 10(-5) min(-1) (R-2 = 0.998), respectively. It is hardly to prepare the alternating structure just through increasing the monomer feed ratios. (C) 2016 Elsevier Ltd. All rights reserved.

ABSTRACTHigh impact polystyrene (HIPS) resins were obtained with in situ bulk polymerization toughened by styrene–isoprene–butadiene terpolymer rubber (SIBR). SIBR prepolymer was prepared through selective polymerization of styrene (St), isoprene (Ip), and butadiene (Bd) in St with [Nd]/[Al]/[Cl] catalyst. Nd‐based catalyst exhibited more favorable activity toward conjugated diene other than St, resulting in St solution of random SIBR with high cis‐1,4 stereoregularity and low St content, which was directly exposed to the free radical polymerization of St to generate HIPS. Effect of toughened rubber and the initiators [difunctional (D2) and trifunctional (T3)] were examined to attain HIPS possessing mechanical properties as follow: impact strength, 0.9–24.8 kJ/m2; tensile strength, 16.0–27.5 MPa; and elongation at break, 7.4–107.0%. Increasing SIBR matrix in HIPS improved the impact strength and decreased tensile strength. The fracture surface morphologies of HIPS specimens were studied by notched impact tests and scanning electron microscopy (SEM), illustrating that the incremental SIBR matrix presented synergistic toughening effect of crazing to enhance the ductile fracture behavior. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43979.

Sequence-determined bottlebrush polymers are precisely, efficiently and conveniently synthesized.

Radius growth rate of spherulites (G) versus crystallization temperature (Tc) for graft PLLA with different graft density and graft length.

In-chain functionalized polystyrenes with different sequential arrangements of functional groups are preparedvialiving anionic copolymerization. The sequence structures are determined by time sampling to establish the sequence-determination method.

An efficient method to combine the NMRP with click chemistry for the synthesis of colorant modified polystyrene was realized.

Front Cover: An efficient and convenient strategy is developed to construct dense grafted polymers with a controlled distribution of branch points. Living anionic polymerization and hydrosilylation are combined effectively to control the distribution of silyl-hydride groups uniformly, alternately and gradiently along the chain. Thereby, polymeric brushes are grafted onto the backbones with high efficiency and convenience. Further details can be found in the article by H. Ma, Q. Wang, W. Sang, L. Han, P. Liu, J. Chen, Y. Li,* and Y. Wang on page 726.

Random styrene (St)–butadiene (Bd) copolymer (SBR) was obtained with the catalyst system composed of Nd(P507)3, methylaluminoxane (MAO) and indene. This Nd-based catalyst system showed high activity and selectivity toward the copolymerization. Indene was proven to be the critical component to achieve the high content of St units (~33.0 %). Raising the polymerization temperature was beneficial to enhance the coordination of St to the active center, affording the increased yield and number-average molecular weight (M n ) of SBR. The polymers obtained in aliphatic solvents possessed higher M n than M n of SBR generated in toluene. The composition of SBR was controllable by adjusting the feed ratio of St/Bd. NMR and DSC analysis illustrated that the copolymers sustained random distribution even when St incorporation in SBR was up to 33.0 %. SBR was fully characterized by NMR, FTIR, GPC and DSC analysis.

Boric acid (1, B(OH)(3)) was investigated as metal-free biocatalyst for its activity towards the bulk ring-opening polymerization (ROP) of epsilon-caprolactone (CL) initiated by benzyl alcohol (BnOH). Moreover, other boric acid derivates such as phenylboronic acid (2), 2-thienylboronic acid (3), 2-furanylboronic acid (4) and 5-pyrimidinylboronic acid (5) were also used as acidic catalysts to synthesize poly(epsilon-capro-lactone) (PCL), poly(delta-valerolactone) (PVL) and poly(trimethylene carbonate) (PTMC). The studies on the polymerization kinetics for all catalysts confirm that the reaction rates are first-order with respect to monomer and their catalytic activities follow the order 1 > 3 > 2 approximate to 4 > 5. Furthermore, the block copolymerization of epsilon-caprolactone (CL) with delta-valerolactone (VL) and trimethylene carbonate (TMC) successfully proceeded by the sequential monomer addition to give PCL-b-PVL and PTMC-b-PCL co-polymers, indicating the living nature of the present polymerization system. The end group analysis by H-1 NMR and MALDI-TOF MS measurements suggested that the benzyl moiety of initiator inserted into the synthesized polymeric chain. The existence of the interaction between the catalyst B(OH)(3) and the monomer CL supports that B(OH)(3) catalyzed ROP of CL preferred an activated monomer mechanism. A possible model for the initiation and propagation procedures of ROP of cyclic esters catalyzed by boric acid in the presence of benzyl alcohol was proposed. (C) 2015 Elsevier Ltd. All rights reserved.

Two DendriMac polymers (Dendri-hydr and Dendri-click) are efficiently and conveniently synthesized via the combination of living anionic polymerization (LAP) and hydrosilylation/click chemistry. Based on the end-capping of DPE derivatives (DPE-SiH and DPE-DA) toward polymeric anions, the polymeric core and arms are effectively synthesized, and the base polymers can be regarded as polymeric bricks. Hydrosilylation and click chemistry are used as coupling reactions to construct the DendriMac polymers with high efficiency and convenience. The numbers of branched arms are calculated by SEC as 5.84 and 6.08 for Dendri-hydr and Dendri-click, respectively, which indicate that the DendriMac architectures exhibit high structural integrity. Because of its independence, high efficiency, and convenience, the whole construction can be regarded as the "building of polymeric bricks."

A new series of linearcomb and 4-arm starcomb side chain liquid crystalline polymers (Lc-/Sc-SCLCPs) have been synthesized and characterized. The treatment of hydride siloxane-containing terminated liquid crystalline and high 1,2-/1,4- (high vinyl, hv/low vinyl, lv) linear or 4-arm star polybutadienes (L-/S-PBs) was conducted via the methods in combination of living anionic polymerization and reverse hydrosilylation to obtain SCLCPs with wide mesomorphic temperature range (?T) and narrow polydispersity index (PDI). The possible molecular arrangement model of two analogous hv-/lv-architectures was constructed, that was used to systematically investigate the effects of Lc- and Sc- topological morphology on liquid crystalline (LC) properties and molecular microstructures. SCLCPs exhibited the same smectic A phase around room temperature, but thermal properties were significantly different due to differences of interaction force resulting from different macromolecular side chains packing. Surprisingly, the trend of lv-SCLCP displaying the effects of topology on phase transitions and microstructures was just contrary to that of hv-topology. hv-Sc-SCLCPs containing high density mesogenic composition were desired to generate wider Delta T and higher molecular layer order in comparison with Lc analogues, which provided a unexpected analyzed model that are of interest to be explored. In particular, the uniaue differences of macromolecular aggregation state arrangement in liquid crystal state dependent on free cooling between hv-Lc- and Sc-SCLCPs were observed from POM.

By combining living anionic polymerization and hydrosilylation, densely grafted bottlebrush polymers with controlled spacing of branch points are prepared. Dimethyl(4-vinylphenyl)silane and dimethyl(4-(1-phenylvinyl)phenyl)silane are anionically (co)polymerized to synthesize uniform, alternating, and gradient in-chain silyl-hydride (Si-H) functionalized backbones. The spacing of branch points is controlled effectively by regulating the distribution of Si-H groups along the backbones. Three backbones with a similar number of Si-H groups but variable distributions are used to synthesize corresponding bottlebrush polymers via hydrosilylation between the backbones and chain-end vinyl functionalized polystyrene. The uniformly grafted bottlebrush exhibits the highest hydrodynamic radius (Rh ) of 5.6 nm and the lowest Tg of 79 °C which may be attributed to its compact grafted structure. This methodology exhibits high efficiency and convenience for the construction of bottlebrushes with controlled distribution of brushes.

The crystallization ability of PLLA with different chain structures.

The copolymerization of epichlorohydrin( ECH),epoxyethane( EO) and allyl glycidyl ether( AGE) was carried out in toluene with Al( i-Bu)3( simplified as Al) /H3PO4/1,8-diazo-bicyclo [5. 4. 0]undecene-7( DBU) catalytic system. The effects of the catalyst composition,adding mode of catalyst components,aging temperature and time on polymerization were investigated, and the synthesized epichlorohydrin rubber was characterized. The results showed that the conversion of monomers reached 97% under the conditions of H2 O in H3PO40,H3PO4/ Al( mole ratio) 0. 35,DBU / Al( mole ratio) 0. 5, aging temperature 60 ℃, aging time2. 0 h and adding mode Al + H3PO4+ DBU. The polymer was composed of EO,ECH and AGE,and the glass transition temperature was- 47. 2 ℃ when the mole ratio of EO / ECH / AGE was 56 /40 /4.

采用三异丁基铝-正磷酸-1,8-二氮杂二环[5.4.0]十一碳-7-烯主催化剂、P2O5助催化剂进行ECH-EO-AGE三元共聚合反应,通过黏度法、傅里叶变换红外光谱、核磁共振碳谱及差示扫描量热法对共聚物进行了表征.结果表明,添加P205助催化剂,在实验范围内可使转化率从52.4％提高到96.4％,共聚物特性黏数从1.16 dL/g增加到1.56 dL/g,表明催化剂的催化活性显著提高.同时,当P205质量分数从0增加到27％时,三元共聚物组成发生较大变化,ECH和AGE组分含量不断增大,而EO含量却显著下降,表明控制P2O5用量即可有效调控三元组成含量;P2O5的加入能使共聚物的玻璃化转变温度有所提高.

功能化已成为实现高分子材料高性能化的重要途径,高分子材料的功能化已从端基官能化向链中官能化发展.本文评述了基于活性阴离子聚合方法高枝化聚合物及链中功能性聚合物的合成方法.以实现链中功能性聚合物“定性、定位、定量”为目标,通过硅氧键(DPE-SiO)、硅氢键(DPE-SiH)与功能性试剂之间的转换反应将目标官能团键入到聚合物链中.系统评述了复杂拓扑结构链中功能性高枝化聚合物的合成方法以及结构与性能之间的构效关系.

In-chain multi-functionalized polybutadiene possessing definite geminal dimethylamino groups along polymer backbone, poly(butadiene-co-1,1-bis(4-dimethylaminophenyl)ethylene), has been designed and synthesized via anionic copolymerization of butadiene with 1,1-bis(4-dimethylanimophenyl)ethylene using sec-butyllithium as initiator. Narrow molecular weight distribution copolymers with Mn = 12-28kg/mol (Mw/Mn < 1.10) were characterized by size exclusion chromatography, H-1-NMR spectroscopy and DSC. The amine functionality was readily controlled by the amount of polar modifiers appropriately selected and the polymer molecular weight. The incorporation of 1,1-bis(4-dimethylanimophenyl)ethylene unit resulted in increases in glass transition temperatures of copolymers and had little effect on butadiene microstructure.