Zur kristallstruktur der polycarbonate aus 4,4′-dihydroxydiphenyl-2,2-propan, 4,4′-dihydroxydiphenylsulfid und 4,4′-dihydroxydiphenylmethan

The polycarbonate from 4,4′-dihydroxydiphenyl-2,2-propane crystallizes monoclinically in the space group C_s² with four chains each in the lattice cell, but the polycarbonate from 4,4′-dihydroxydiphenyl sulfide and from 4,4′-dihydroxydiphenyl methane crystallizes orthorhombically in the space group C_2v⁹ with two chains each in the lattice cell. In all three substances, the fibre identity period always comprises two monomeric units, so that always eight and always four monomeric units, respectively, are located in the lattice cell. The crystal densities are 1.315 g./ccm. for the polycarbonate from 4,4′-dihydroxydiphenyl-2,2-propane, 1.50 g./ccm. for the polycarbonate from 4,4′-dihydroxydiphenyl sulfide, and 1.303 g./ccm. for the polycarbonate from 4,4′-dihydroxydiphenyl methane. The fibre identity period of the three substances, as compared with their theoretical maximum length in the case of fully stretched chains, has been shortened by 15 per cent to 20 per cent. Accordingly, the crystal elasticity modulus in the direction of the chain only amounts to about 450 to 600 kp./mm². The crystal structures considered do not contain any glide planes, so that the crystal domains possess a high shear strength. The low crystallization tendency of the polycarbonate from 4,4′-dihydroxydiphenyl-2,2-propane is easily and plausibly accounted for by its crystal structure.     

Mechano-chemischer abbau bei der schwingmahlung von poly(ε-caprolactam) in gegenwart von sebacoylchlorid und nachfolgende polykondensation mit aromatischen diaminen

Mechano-chemical degradation of poly(ε-caprolactam) {poly[imino(1-oxohexamethylene)]} in the presence of sebacoyl chloride, carried out by vibratory milling, gave polyamide acid chlorides. Subsequently, these products, also by vibratory milling, were condensed with p-phenylenediamine to obtain polymers with aromatic amino groups which by diazotation and coupling reaction were transformed into coloured polymers. The use of some specially selected coupling components (i.e. containing itself primary amino groups) allowed to regulate the colour intensity of the final product when the diazotation and coupling reaction was carried out gradually.     

Polymers of carbonic acid, 5. Nematic polyurethanes derived from 4,4′-dihydroxybiphenyl and 4,4′-bipiperidine,ethylene-4,4′-bipiperidine or trimethylene-4,4′-bipiperidine

4,4′-Bipiperidine ( 3a ), 1,2-bis(4-piperidinyl)ethane ( 3b ) and 1,3-bis(4-piperidinyl)propane ( 3c ) were condensed with the dichloroformates of p-phenylene, 2-methyl-1,4-phenylene or 2,5-biphenylylene. Furthermore, two copolyurethanes were prepared either by mixing 3a and 3c or by mixing the dichloroformates for p-phenylene and 2,5-biphenylylene. Inherent viscosities between of 0,6 and 1,7 dl/g were found for the polyurethanes of 3c , but only values below 0,86 dl/g for those of 3a and 3b . The polyurethanes derived from hydroquinone or methylhydroquinone are semicrystalline polymers with a short-term thermostability up to 310°C. The polyurethanes deriving from phenylhydroquinone are amorphous with a thermostability up to 360°C. The homo-and copolyurethanes containing 4,4′-biphenylylene units form a smectic layer structure in the solid state and a nematic melt above the melting point.     

Zur struktur der produkte der reaktion von 2-cyano-2-propylradikalen mit 1,4-benzochinon

The products of the reaction of 2-cyano-2-propyl radicals with 1,4-benzoquinone in toluene solution have been investigated by ¹H NMR spectroscopy and mass spectroscopy. In agreement with the findings of Bickel and Waters the main reaction products are the hydroquinone monoether 1 and the hydroquinone diether 2 . In addition two ringsubstituted products, 5 and 6 , have been obtained. The structures 3 and 4 , which have been proposed for the main products by Yassin and Rizk, are shown to be in error.     

Untersuchungen einiger gesetzmäßigkeiten der polykondensation von tetracarbonsäure-tetranitrilen mit diaminen sowie der eigenschaften der entstehenden polymere

Polyhexazocyclanes, a new type of polymers with nitrogen containing macroheterocycles in the chain, are obtained by polycondensation of tetranitriles of tetracarboxylic acids with diamines with generation of ammonia. The study of a model reaction of phthalodinitrile with p-phenylenediamine in various media containing a hydroxyl group showed that unlike the condensation in aliphatic alcohols, the condensation in phenol and cresols allows the formation of macrocyclic compounds in high yields. There is no formation of macroheterocycles when conducting the condensation in phenols with electron withdrawing substituents. The reaction of ammonia with a model heterocycle leads to the formation of a number of intermediates of its synthesis. This leads to the assumption the formation of the model compound and, consequently, the polycondensation of tetranitriles with diamines to be an equilibrium process. Polyhexazocyclanes are thermally stable polymers. The decomposition point in air exceeds 400°C. On heating above 250°C the polymers are cross-linking and do not soften up to the temperature of their decomposition.     

Copolymerisation of 4,4′-divinylbiphenyl and of 4,4′-diisopropenylbiphenyl with styrene in solution

Styrene has been copolymerised with 4,4′-divinylbiphenyl and with 4,4′-diisopropenylbiphenyl in 15% toluene solution at 95°C. The copolymers have been analysed via UV spectroscopy, to give estimates of total crosslinker incorporated and of the number of pendant double bonds remaining. Extrapolation of the results—including viscometry—to zero conversion indicates that both crosslinkers form intramolecular linkages (rings). These rings appear to be comparable in size with those formed with p-divinylbenzene, but to occur rather more frequently. Estimates of copolymerisation reactivity ratios r₁ (styrene=1) are, for 4,4′-divinylbiphenyl 0,77, for 4,4′-diisopropenylbiphenyl 1,3. It is concluded that, contrary to a previous suggestion, increasing separation of reactive groups leads to more, not less, intramolecular reaction.     

Untersuchung der grignard-wurtz-reaktion von partiell hydrobromiertem 1,4-polybutadien und partiell α-bromiertem polyoctenylen durch metathese-abbau der polymere und identifizierung der niedermolekularen produkte

Partially hydrobrominated 1,4-polybutadiene and α-brominated polyoctenylene were treated with pentyl, isopropyl, cyclohexyl, benzyl, 4-methylbenzyl, phenyl, 4-methylphenyl, 4-ethylphenyl, 3,4-dimethylphenyl, 2,4,6-trimethylphenyl, 4-chlorophenyl, 4-fluorophenyl, 4-methoxyphenyl, 3,4-dimethoxyphenyl, and 2-thienyl magnesium bromide. In addition partially hydrobrominated 1,4-polybutadiene was treated with 2-methylbenzyl, 3-methylbenzyl and 4-isopropylphenyl magnesium bromide. Polymers were degraded by metathesis with 4-octene using WCl₆/(CH₃)₄Sn as a catalyst. The low molecular products were separated by gas chromatography and identified by mass spectrometry. Mass spectra of products with 4-alkyl(aryl)octanediylidene units (from modified polybutadiene) and 2-alkyl(aryl)octanediylidene units (from polyoctenylene) were compared.     

Gelchromatographische analyse der produkte der diels-alder-reaktion von chloropren

DIELS -ALDER reactions and the thermal polymerization of chloroprene were quantitatively followed by means of gel chromatography. Using a system of highly efficient chromatographic columns filled with a suspension copolymer of styrene/divinylbenzene, the separation of cyclic chloroprene dimers along with the monomer and the polymer was achieved. The temperature dependence of the rate constant of monomer consumption obtained by GPC is in a very good agreement with values obtained by gas chromatography and dilatometry.     

Reaktionen mono- und bifunktioneller thiocarbonsäuren mit mono- und bifunktionellen isocyanaten oder isothiocyanaten

Thiocarboxylic acids react faster with isocyanates or isothiocyanates than the corresponding carboxylic acids. The primary reaction products are carbamic acid carboxylic acid thioanhydrides and carboxylic thiocarbamic acid thioanhydrides, which can be isolated only in some cases at low temperatures. On heating amides are formed as the main products and in the case of aromatic isocyanates diarylureas are also obtained. The reaction of α,ω-dithio carboxylic acids with diisocyanates or with diisothiocyanates leads to poly[thiocarbonylimino-(6-oxohexamethylenes)] (poly thioanhydrides) or at higher temperatures to polyamides of the nylon type. The heating of 6-isocyanato or 6-isothiocyanato hexanethioic acid trimethylsilyl ester with alcohols or phenols above 200°C produces Nylon-6 with molecular weights up to 10000.     

Disproportionierung und kombination als abbruchmechanismen bei der radikalischen polymerisation von styrol, 1.Versuche mit 14C-markierten 2,2′-azoisobutyronitril

Bulk polymerisation of styrene initiated by ¹⁴C-labelled 2,2′-azoisobutyronitrile (AIBN) was studied at 52°C. The polymerisation was controlled dilatometrically, the molecular weights of the resulting polymers were measured viscometrically, the weight fraction of the one chain molecules was determined by gel permeation chromatography, and the number of labelled end groups was counted. The detailed kinetic analysis affords consistent conclusions, particulary about the mechanism of termination. It is concluded, that in styrene polymerisation both disproportionation and combination compete with each other.     

Polychelates derived from 4,4′-(4,4′-biphenylylenebisazo)di(salicylaldehyde oxime)

Polychelates of Ni(II), Co(II), Cu(II), Zn(II), and Mn(II) were synthesized from bis 4,4′-(4,4′-biphenylenebisazo)di(salicylaldehyde oxime) and metal chlorides. All the chelates are dark in colour and insoluble in common organic solvents. Their most probable structures were determined by visible reflectance spectroscopy and magnetic measurements in conjunction with thermogravimetric and IR measurements. Elemental analyses indicate a ligand: metal ratio of 1:1 and the association of water molecules with the central metal. The decomposition temperatures of the polychelates decrease in the following order: Zn(II) > Co(II) > Ni(II) > Mn(II) > Cu(II).     

High performance aromatic polyimide fibers, 3. A polyimide synthesized from 3,3′,4,4′-biphenyltetracarboxylic dianhydride and 2,2′-dimethyl-4,4′-diaminobiphenyl

A new high molecular weight aromatic polyimide has been synthesized from 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA) and 2,2′-dimethyl-4,4′-diaminobiphenyl (DMB) in p-chlorophenol at elevated temperature. BPDA-DMB fibers have been spun by a dry-jet wet spinning method. The fibers were elongated and annealed at elevated temperatures above 400°C to achieve excellent mechanical properties. In seven times drawn fibers, the BPDA-DMB molecule packs into a triclinic unit cell with dimensions of a = 2,10(2) nm, b = 1,523(8) nm, c = 4,12(7) nm, α = 61,2(6)°, β = 50,7(7)°, and γ = 78,9(6)° with the number of chain repeating units per unit cell (Z) is sixteen. After annealing at elevated temperatures, the fibers produce a small modification of the unit cell [a = 2,048(6) nm, b = 1,529(5) nm, c = 4,00(2) nm, α = 62,1(3)°, β = 52,2(3)° and γ = 79,6(3)°]. By increasing the draw ratio, both the crystallinity and crystal orientation increase. The BPDA-DMB fibers possess a decomposition temperature of 530°C in nitrogen and 500°C in air at a 5% weight loss when the heating rate is 10°C/min. After extensive drawing, BPDA-DMB fibers exhibit a tensile strength of 3,3 GPa and a tensile modulus of over 130 GPa. Dynamic mechanical behavior of the fibers show both α (glass transition) and β (sub-glass transition) relaxations above room temperature. The nature of the sub-glass transition behavior is described as a noncooperative motion attributed to the diamine portion of the molecule. The activation energy for this relaxation in as-spun fibers is 109 kJ/mol and increases to 144 kJ/mol by increasing the draw ratio. This β relaxation is found to be crystallinity dependent. The α transition is also suppressed by crystallinity which increases with draw ratio.     

Bestimmung der geschwindigkeitskonstanten und der effektivitäten beim zerfall von 2,2′-azoisobutyronitril in styrol,N-vinyl-2-pyrrolidon und methylmethacrylat

The decomposition rate constants k_d of initiators can be determined by a new method directly in monomers as solvents. If a suitable inhibitor is added to a monomer mixture with the initiator the latter decomposes nearly without monomer conversion. The initiator concentration—after the inhibitor is consumed—can be found by means of the dilatometrically determined polymerization rate after the induction period. The functional connection between polymerization rate and initiator concentration found without inhibitor is used as a calibration curve for that purpose. The dilatometrical measurements were made in the monomers styrene and N-vinyl-2-pyrrolidone using 2,2′-azoisobutyronitrile (AIBN) as initiator and p-quinone as inhibitor. The following decomposition rate constants were found: k_d=1,52 · 10^?5 S^?1 (styrene) and k_d=1,62 · 10^?5 S^?1 (N-vinyl-2-pyrrolidone), which is in agreement with literature values. Initiator efficiencies f were calculated: f=0,46 (styrene), f=0,47 (N-vinyl-2-pyrrolidone). In methyl methacrylate (MMA) 2,2′-diphenyl-1-picrylhydrazyl (DPPH) was used as inhibitor. Under certain conditions the product k_df can be calculated from the consumption rate of DPPH. The value found in MMA (k_df=3,7 · 10^?6 s^?1) is lower than that reported in literature (6,45 · 10^?6 s^?1).     

Thermotropic para-linked aromatic polyesters containing 1,1′-binaphthyl-4,4′-ylene units

Synthesis, thermal properties and solubility behaviour of para-linked aromatic homopolyesters containing non-coplanar 1,1′-binaphthyl-4,4′-ylene units are described. By combining such binaphthylylene units with monosubstituted phenylene units, crystallization can be suppressed and thermotropic liquid-crystalline polyesters with glass transition temperatures (T_g) up to 190°C are obtainable. The liquid-crystalline order is maintained below T_g in an anisotropic glass. The polyesters show good solubility in common organic solvents, such as chloroform or tetrahydrofuran.     

Gemischte Diester von 2,2′-Methylendiphenolen mit Methacryl- und Crotonsäure und ihre Polymeren. 13C NMR-Untersuchungen zur Strukturaufklärung

The structure of mixed diesters of three 2,2′-methylenediphenols with crotonic acid and methacrylic acid was studied by ¹³C NMR-spectroscopy. The position of the two acyl groups, expected from the synthetic pathway, was unambiguously confirmed by comparison with the corresponding mono- and diesters containing the same acyl group. In the same way, it was shown that the crotonoyl residue is not involved in the radical polymerisation of these esters.     

Synthesis of polyamides containing 4,4′-azodibenzamido units

Four coloured polyamides containing azo-p-phenylene units were synthesised from 4,4′-azodibenzoic acid and four aromatic diamines employing both interfacial and solution polymerization procedures. The polymers were characterized by their UV and IR spectra, by inherent viscosity measurements and by solubility data. The stability in conc. sulfuric acid and the thermal behaviour are discussed.     

Kinetik der Wachstumsreaktionen der Copolymerisation von Butadien und Styrol mit Lithiumorganylen

The rate constants of the propagation reactions of the lithiumalkyl catalyzed copolymerization of butadiene and styrene in toluene were measured and their rate constants and activation energies and the association constants of the initiators were determined. It turned out, that the cross reaction of styryllithium with butadiene is faster by a factor of 100 as hitherto assumed. The problems in determining rate constants from copolymerization reactivity ratios are discussed.     

Sequenzspezifische Cooligokondensation von Nucleinsäure-Bausteinen mit Affinitäts-Schutzgruppen, 2. Cooligomere von 5′-O-[p-Anisyldiphenylmethyl]thymidin und Desoxynucleotiden

The cooligocondensations of 5′-O-[p-anisyldiphenylmethyl]thymidine with thymidylic acid, derivatives of deoxycytidylic acid and deoxyguanylic acid were studied. The cooligomers MMTrdT(pdN)_n (N = nucleoside) were first removed from homooligomers and unreacted nucleotide by passing the reaction mixture through a column of trityl cellulose, then the separation depending on the chain length was achieved on DEAE-cellulose. In the example studied best—the cooligocondensation with N-isobutyryldeoxyguanosine-5′ phosphate—the nucleoside component was completely inserted into the cooligomers; the sequences of chain length 2, 3, 4, and 5 were obtained in 77, 18, 3 and 2% yield. The mean chain length of the product can be altered e.g. by variation of blocking groups and the ratio of starting compounds.     

Polymers of carbonic acid, 23. Photoreactive cholesteric polycarbonates based on isosorbide, 4,4′-dihydroxychalcone and 4,4′-dihydroxybiphenyl

Numerous copolycarbonates were prepared from 4,4′-dihydroxychalcone, on the one hand, and methylhydroquinone, 4,4′-dihydroxybiphenyl or isosorbide (1,4:3,6-dianhydro-D-sorbitol), on the other. Three different polycondensation methods were compared, but polycondensation in an organic solvent using diphosgene as condensing agent proved to be the most satisfactory. The resulting copolycarbonates were characterized by their inherent viscosities, elemental analyses, infrared (IR), ¹H nuclear magnetic resonance (NMR) and ¹³C NMR spectra, by differential scanning calorimetry (DSC) measurements and by optical microscopy. The ¹³C NMR spectra proved the formation of almost random sequences in all cases. In contrast to the homopolycarbonate of chalcone which is crystalline and insoluble in inert solvents, all copolycarbonates of chalcone are completely or largely amorphous and soluble. Whereas 4,4′-dihydroxychalcone itself proved to be nonmesogenic, copolycarbonates containing 4,4′-dihydroxybiphenyl are thermotropic. Ternary copolycarbonates containing isosorbide as a chiral component are cholesteric and form Grandjean textures upon shearing in the molten state. Ultraviolet (UV) irradiation of thin films resulted in crosslinking.     

Über N-(isothiocyanatoacylamino)carbonsäuren und ihre kondensationspolymerisation zu copolyamiden mit alternierender sequenz

N-Isothiocyanatoacylamino carboxylic acids are crystalline monomers, which were prepared from ω-isothiocyanato carboxylic acid chlorides and various aliphatic or aromatic amino carboxylic acids. Their condensation polymerization to copolyamides was investigated under various conditions. At reaction temperatures ≤200°C exclusively copolyamides with an alternating sequence were formed, whereas at 250°C amide exchange reactions brought about copolyamides with short homologous blocks. The sequence analysis was achieved by ¹H-NMR- or by ¹³C-NMR-spectroscopy. The average molecular weights of all copolyamides were found to be in the range of 5–10000.