Hydrochlorinated derivatives of syndiotactic 1,2-polybutadiene

Chlorine-containing polymeric products with a degree of functionalization of up to 70% are synthesized through the hydrochlorination of syndiotactic 1,2-polybutadiene via carbon-carbon double bonds. The introduction of chlorine atoms into polydiene units causes substantial changes in the viscosity of polymer solutions, the flowability of the polymer melt, the glass-transition and flow temperatures, and the thermal stability of polymers. The hydrochlorinated derivatives of syndiotactic 1,2-polybutadiene demonstrate good adhesion with respect to steel and can be used in adhesive compositions.     

Chlorinated polymers based on low-molecular-weight 1,2-polybutadiene

Chlorinated polymeric products were synthesized from 1,2-polybutadiene by introduction of chlorine atoms into macromolecules at carbon carbon double bonds.     

自成核对间同立构1,2-聚丁二烯结晶行为的影响

间同立构 1 ,2 -聚丁二烯自 1 95 5年问世以来 ,引起人们的广泛关注 ,但其形态结构方面的研究却很少报道 [1] .原因是间同立构 1 ,2 -聚丁二烯分子侧链含有大量双键 ,在较高温度下 ( >1 5 0℃ )很容易产生热交联 ,严重影响该聚合物的结晶行为 .我们曾报道了结晶性间同立构 1 ,2 -聚丁二烯的合成和溶液浇铸膜的板条状结构以及单晶结构 [2 ,3] .本文研究了间同立构 1 ,2 -聚丁二烯的自成核过程、结晶行为和形态结构 .自成核 ( Self- seeding nu-cleation)是指聚合物自身的微小晶粒作为晶核而诱导结晶生长的一种成核方式 ,它具有很高的成核效…     

Thermal degradation of halogen derivatives of syndiotactic 1,2-polybutadiene

Thermal degradation of halogen derivatives of syndiotactic 1,2-polybutadiene, differing in the kind of the halogen, its content in the polymeric product, and its position in the monomeric unit, was studied by thermal gravimetric analysis. Comparative evaluation of the heat resistance of the halogenated polymers under consideration was made.     

Radiation-Induced Addition Reaction of Ethyl Mercaptan and Carbon Tetrachloride to 1,2-Polybutadiene

γ-Ray-induced addition reactions of syndiotactic 1,2-polybuta-diene film with various compounds were carried out at room temperature. The weight of the film markedly increased when ethyl mercaptan was used. In the reaction with ethyl mercaptan, only addition took place without crosslinking. The addition of ethyl mercaptan to the vinyl group of syndiotactic 1,2-poly-butadiene followed anti-Markownikoff rule, and gave a 1:1 addition product. The rate of addition increased as the crys-tallinity of syndiotactic 1,2-polybutadiene used became lower. A similar relation between the crystallinity and the rate of addition was also observed in the γ-ray-induced addition of carbon tetrachloride to syndiotactic 1,2-polybutadiene, but at the same time gelation was pronounced. When liquid 1,2-polybutadiene was used instead of syndiotactic-1,2-polybutadiene, gelation which made the polymer insoluble in carbon tetrachloride did not take place, although a crosslinking reaction was noted. The appearance of the product in this case changed from a viscous liquid to a white powder as the reaction proceeded. The addition of carbon tetrachloride to the vinyl group of liquid 1,2-polybutadiene was also of the anti-Markownikoff type. This addition was accompanied by unexpectedly large vinyl consumption. The total decrease in vinyl group was found to be much larger than the decrease in vinyl group which was brought about by the addition of carbon tetrachloride. This discrepancy was attributed to cyclization and crosslinking reactions which were ascribed to the vinyl group bound by the main chain.     

Syndiotactic 1,2-polybutadiene with Co-CS2 catalyst system. I. Preparation,properties, and application of highly crystalline syndiotactic 1,2-polybutadiene

Highly crystalline syndiotactic 1,2-polybutadiene (s-PB) having melting point (mp) up to 216°C was obtained by using a Co(acac)₃-AIEt₃-CS₂ catalyst. The polymer with mp 208°C was found to have 99.7% 1,2 content and 99.6% syndiotacticity by ¹H and ¹³C-NMR measurements. The s-PB can be molded by addition of a stabilizer such as 2,6-di-t-butyl-4-hydroxymethylphenol into fiber, film, and various shaped articles. The physical properties presented in the present article include stress-strain and dynamic mechanical behavior. The highly crystalline syndiotactic 1,2-polybutadiene was applied to a carbon fiber and UBEPOL VCR (cis-1,4-polybutadiene reinforced by fibrous syndiotactic 1,2-polybutadiene).     

Properties of modified polymers based on syndiotactic 1,2-polybutadiene

The influence of the chemical modification on the properties of syndiotactic 1,2-polybutadiene derivatives that contain various functional groups in macromolecules and show promise for practical use was studied. The dependence of the glass transition point and the fluidity and rheological properties of modified polydiene melts on the nature of the functional group in the macrochain and on the degree of the polymer functionalization was revealed. The possibility of directional synthesis of modified polymer products with the required operation characteristics on the basis of syndiotactic 1,2-polybutadiene was demonstrated.     

Viscoelastic and rheological properties of syndiotactic 1,2-polybutadiene

The physicomechanical, viscoelastic, and rheological characteristics of syndiotactic 1,2-polybutadiene were studied and compared with those of the analogs produced in other countries.     

Polymer-asphalt compounds based on 1,2-polybutadienes

Properties of polymer-asphalt compounds containing 1,2-polybutadienes differing in the molecular weight and structure of macromolecules were examined. Introduction of syndiotactic 1,2-polybutadiene in combination with a plasticizing additive noticeably improves the main service properties of asphalts.     

Epoxidation of syndiotactic 1,2-polybutadiene with peracids

The epoxidation of syndiotactic 1,2-polybutadiene (84 and 16% 1,2 and 1,4 units, respectively) with carboxylic peracids prepared in situ and m-chloroperbenzoic acid was studied. In the course of epoxidation in the presence of carboxylic peracids, oxirane groups are formed only through epoxidation of double bonds in the macromolecular backbone, whereas m-chloroperbenzoic acid is responsible for the chemical modification of 1,2 and 1,4 units of polybutadiene. The basic kinetic parameters of 1,2-polybutadiene epoxidation with peracids of various chemical structures were determined.     

Cu(OAc)2-2,4-lutidine-ZnCl2 as an effective catalyst of functionalization of isobutylene oligomers and 1,2-polybutadiene with methyl diazoacetate

The possibility of [1+2]-cycloaddition of methoxycarbonylcarbene generated by catalytic decomposition of methyl diazoacetate in the presence of the Cu(OAc)₂-2,4-lutidine-ZnCl₂ system to the carbon-carbon double bound in isobutylene oligomers and syndiotactic 1,2-polybutadiene was examined. A comparative analysis of physicochemical properties of the starting compounds and their functionalized products was performed.     

A general route to very small polymer particles with controlled microstructures

Very small polymer particles of 10-30 nm size with various microstructures (polyethylene, syndiotactic 1,2-polybutadiene, poly(cycloolefins)) are prepared by catalytic polymerization with aqueous catalyst microemulsion.     

Radiation-induced addition reaction of carbon tetrachloride onto 1,2-polybutadiene

The γ-ray-induced addition reaction of carbon tetrachloride onto syndiotactic 1,2-polybutadiene film and liquid 1,2-polybutadiene was carried out at room temperature. In the film gelation was pronounced and the rate of addition increased as the crystallinity of the polymer decreased. In the liquid gelation, which makes the polymer insoluble in carbon tetrachloride, did not take place, although a definite crosslinking reaction was noticed. In this case the appearance of the product changed from a viscous liquid to a white powder as the reaction proceeded. Its structure was compared with that of chlorinated 1,2-polybutadiene. The addition of carbon tetrachloride to the vinyl group in liquid 1,2-polybutadiene caused an anti-Markownikoff-type reaction and was accompanied by an unexpectedly large vinyl depletion in the polymer. The total decrease in the vinyl group was found to be much larger than that brought about by the addition of carbon tetrachloride. This discrepancy was attributed to a cyclization and crosslinking reaction ascribed to the vinyl group bound by the main chain. Cyclization and crosslinking were less noticeable in the chlorination than in the carbon tetrachloride.     

Dichlorocyclopropane derivatives of syndiotactic 1,2-polybutadiene

Polymeric products containing hem-dichlorocyclopropane units with a degree of functionalization of up to 97% are synthesized via the reaction of syndiotactic 1,2-polybutadiene with dichlorocarbene obtained by the interaction of chloroform with an aqueous solution of sodium hydroxide in the presence of a phase-transfer catalyst. The incorporation of dichlorocyclopropane groups into units of polydiene substantially changes its molecular mass and polydispersity, the solution viscosity, the polymer melt flowability, and the glass-transition temperature and flow temperature of the polymer.     

Arylamino-derivatives of syndiotactic 1,2-polybutadiene

The chemical modification of syndiotactic 1,2-polybutadiene via interaction of the polymer with aromatic amines in the presence of sodium tetrachloroaluminate Na[AlCl₄] has been studied. With the use of IR and NMR spectroscopy data, the structure of the modified 1,2-polydiene has been examined.     

间同立构1,2-聚丁二烯的合成和形态结构研究

间同立构 1 ,2 -聚丁二烯自 1 955年问世以来 ,引起人们的广泛关注 ,但绝大多数研究工作集中在聚合物的合成方面[1～ 3] ,对其形态结构方面的研究却很少报道[4 ] ,原因是该聚合物分子侧链含有大量双链 ,在较高温度下 (>1 50℃ )很容易产生热交联 ,这给结构研究造成了很大困难 .间同立构 1 ,2 -聚丁二烯的性能取决于间规度 ,低间规度聚合物呈现弹性体特征 ,而高间规度聚合物则是一种半结晶性塑料 ,其结晶为平面锯齿链正交堆砌 ,Pacm空间群[4 ] .本文采用一种新的催化体系 ,使合成的 1 ,2 -聚丁二烯间规度可以调控 .同时首次报道了结晶性间规…     

Blends of Polypropylene and Syndiotactic 1,2-Polybutadiene:Morphology,Crystallization Behaviors and Mechanical Properties

Morphologies,crystallization behavior and mechanical properties of polypropylene（PP）/syndiotactic 1,2-polybutadiene（s-1,2 PB）blends were investigated.Morphology observation shows the well dispersed domains of s-1,2 PB in PP matrix with the rather small domain sizes from 0.1 to 0.5μm when the s-1,2 PB content increases from 5%to 20%（mass fraction）in the blends,and the phase structure tends to become co-continuous as s-1,2 PB content further increases.Crystallization temperature（Tc）of PP component in the blends is fluctuated with the variation of s-1,2 PB content in the blends.Compatibilization,to some extent,between the two components is inferred from the examination of both morphology and crystallization behavior.Improvement of impact strength of PP toughened by s-1,2 PB becomes significant only in the case of s-1,2 PB content above 20%（mass fraction）.     

双烯类聚合物的热分析Ⅱ.不同含1,2-含量无规聚丁二烯热(氧化)的研究

不同1,2-含量无规聚丁二烯的研究表明,与侧链乙烯基相比,主链双键更易于发生热氧化反应,这可能因其含有较多的α-氢。根据热氧化温度和动力学参数活化能E,钴系高1,2-含量间规聚丁二烯比之钼(或锂)系聚丁二烯更为稳定,前者E值高达150kJ/mol以上,后者为100kJ/mol左右。热交联表观活化能分别为181、166kJ/mol。它们热氧化稳定性的差别,是由于通常钴系聚合物为晶态,锂(或钼)系为非晶态。     

Syndiotactic 1,2-polybutadiene with Co-CS2 catalyst system. IV. Mechanism of syndiotactic polymerization of butadiene with cobalt compounds–organoaluminum–CS2

A mechanism is proposed for the polymerization of syndiotactic 1,2-polybutadiene (s-PB) with soluble cobalt-organoaluminum-CS₂. The proposed active species have structures which consist of side-on coordination of CS₂ to cobalt, anti-π-allyl growing end, cisoid bidentate coordination of butadiene, and activation by complex formation with organoaluminum at the nonbonded sulfur of the coordinated CS₂. This proposal is based on findings for the aluminum-free catalyst Co(C₄H₆)(C₈H₁₃)-CS₂. It is tentatively interpreted that syndiotactic 1,2 polymerization proceeds under the influence of the side-on coordinated CS₂, by which the reactivity between the terminal carbons of butadiene and the C3 of the π-allyl end is enhanced.     

双烯类聚合物的热分析——I.间规1,2-聚丁二烯的熔融-结晶与热氧化

由钴催化体系合成的间规1,2-聚丁二烯是结晶性的,熔点205—210℃,与1,2-链节含量无关。低1,2-含量(12—20mol％)时,热氧化峰温为185℃左右,高1,2-含量(95—100mol％)时,200到240℃。换言之,与主链双键相比,侧链乙烯基的热氧化反应发生在更高的温度,即在熔融后的较窄的温度范围表现出较大的热效应。高1,2-含量间规聚丁二烯热氧化的热效应和活化能值,似与合成转化率有一定联系,当达到一定转化率时,热效应急剧增高,而活化能降低,估计这与残留在试样中催化剂的量及存在形式有关。