This report deals with the improvement for SBR by its modification with compounds of general formula R-X-C=Y-SH, where X is -CH₂-, -O-, -S, or -NH- and Y is CH- O, S or NH. The reaction was carried out in hexane solution of SBR in the presence of organic peroxide as the initiator for radical reaction. Thiobenzamide was found to be one of the most suitable modifier and to yield the vulcanizate of good mechanical property. The vulcanizate of modified SBR ingradiated with precepitated calcium carbonate exhibited 150kg/cm² in tensile strength in comparison with 80kg/cm² for non-modified SBR.

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We have classified structurally a number or of nsual organic rubber chemicals according to general formula, R X-C=Y-Z and as the model compound benzmercapto-imides in which R-X-, =Y, and -Z were phenyl, S and -NH₂ respectively, was investigated in detail for natural rubber. As the results, it was shown that benzmercapto-imide enhanced the vulcanization, especially in the presence of dibenzothiazyl disulfide or tetramethylthiuram disulfide, but it did not act as peptizer nor antioxidant.
Throughout these phenomena we have proposed a mechanism of six membered system for cocatalytic action of benzmercapto-imides.

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Theoretical considerations for polishing of rigid vinyl sheets were developed. Using the results of parallel plastometer measurements and the conditions determined with test polishing apparatus, following equation based on Dienes′ equation was assumed.
1/h₄=8.21×F/10^-6×V²×Kⁿ{1/G₁+1/G₂(1-e^-t/τ₂)+t/η₃}
where
h: thickness of the sample
F: total load
V: volume of the sample
G₁: instantaneous rigidity
G₂: viscoelastic rigidity
t: time
τ₂: retardation time
η₃: viscosity
K and n are constant respectively. After various calculations, it was found that nearly satisfactory pressure or time was obtained when K=V and n=-0.75.

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When carbon black reacts with benzoylperoxide (Bz₂O₂) in pure acetone at 30-50°C, benzoic acid is formed. It the concentrations of Bz₂O₂ are small and reaction periods are long enough so that the residuat peroxide is negligible, benzoic acid formed during these reactions is quantitative for Bz₂O₂ used.
Using a brand of carbon black under a given concentration of Bz₂O₂, the conversion rate of peroxide into benzoic acid is found to be proportional to the total urface areas of the black. Further, the rate of reactions, referred to as the relations between the amount of benzoic acid formed and the concentrations of Bz₂O₂ used is analogous to that observed with some gas reactions on solid surfaces, which is given by a Langmuir type equation. The apparent activation energies are about 9-10kcal for most blacks.
The extent of the reaction under a given treatment at 40°C for the rubber-grade carbon blacks is obtained by plotting the measuring values of benzoic acid formed against their BET surface areas. A plot of furnace type blacks is actually represented by points lying above channel types, presumably because of the difference of their surface roughness and oxygen contents.
On the other hand, the reaction of Bz₂O₂ with blacks in primary and secondary alcohols (for example methyl, ethyl and Isopropylalcohol) at 40°C for 30hrs shows that a part of alcohols is converted to the corresponding aldehydes or ketones.

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Vinyl polymers (PVC, PMMA and PS) are blended using of rolls in air. The blended combination is again separated into two fractions, extracted solution and residue, by means of an either solvent of them. To find a mechanical degradation by which the polymer molecule of each fraction may have been ruptured of C-C chain bond, their intrinsic viscosities are measured respectively. On the polymer-polymer blending, it is found that one or both chain may be ruptured, or none. For example PS bond ruptures give only rise as to PS-PVC blending and PVC chain is stable. Moreover, the mechanical bond rupture of PVC chain and PMMA chain is simultaneous through their blendings.

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